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Friday,May 28, 2010

Part III

Department of Transportation

Federal Aviation Administration

14 CFR Part 91 Automatic Dependent Surveillance— Broadcast (ADS–B) Out PerformanceRequirements To Support Air TrafficControl (ATC) Service; Final Rule

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30160 Federal Register / Vol. 75, No. 103 / Friday, May 28, 2010/ Rules and Regulations

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 91

[Docket No. FAA–2007–29305; Amdt. No.91–314]

RIN 2120–AI92

Automatic Dependent Surveillance—Broadcast (ADS–B) Out PerformanceRequirements To Support Air TrafficControl (ATC) Service

AGENCY : Federal AviationAdministration (FAA), DOT.ACTION : Final rule.SUMMARY : This final rule amends FAAregulations by adding equipagerequirements and performancestandards for Automatic DependentSurveillance—Broadcast (ADS–B) Outavionics on aircraft operating in ClassesA, B, and C airspace, as well as certain

other specified classes of airspacewithin the U.S. National AirspaceSystem (NAS). ADS–B Out broadcastsinformation about an aircraft through anonboard transmitter to a groundreceiver. Use of ADS–B Out will moveair traffic control from a radar-basedsystem to a satellite-derived aircraftlocation system. This action facilitatesthe use of ADS–B for aircraftsurveillance by FAA and Department of Defense (DOD) air traffic controllers tosafely and efficiently accommodateaircraft operations and the expectedincrease in demand for airtransportation. This rule also providesaircraft operators with a platform foradditional flight applications andservices.DATES : This final rule is effective onAugust 11, 2010. The compliance datefor this final rule is January 1, 2020.Affected parties, however, do not haveto comply with the informationcollection requirement in § 91.225 untilthe FAA publishes in the FederalRegister the control number assigned bythe Office of Management and Budget(OMB) for this information collectionrequirement. Publication of the controlnumber notifies the public that OMBhas approved this informationcollection requirement under thePaperwork Reduction Act of 1995. Theincorporation by reference of certainpublications listed in the rule isapproved by the Director of the FederalRegister as of August 11, 2010.FOR FURTHER INFORMATION CONTACT : Fortechnical questions concerning this finalrule, contact Vincent Capezzuto,Surveillance and Broadcast Services,AJE–6, Air Traffic Organization, Federal

Aviation Administration, 800Independence Avenue, SW.,Washington, DC 20591; telephone (202)385–8637; [email protected] .

For legal questions concerning thisfinal rule, contact Lorelei Peter, Officeof the Chief Counsel, AGC–220, FederalAviation Administration, 800Independence Avenue, SW.,

Washington, DC 20591; telephone 202–267–3134; e-mail [email protected] .SUPPLEMENTARY INFORMATION :

Authority for This RulemakingThe FAA’s authority to issue rules on

aviation safety is found in Title 49 of theUnited States Code (49 U.S.C.). SubtitleI, Section 106, describes the authority of the FAA Administrator. Subtitle VII,Aviation Programs, describes in moredetail the scope of the agency’sauthority.

This rulemaking is promulgatedunder the authority described inSubtitle VII, Part A, Subpart I, Section40103, Sovereignty and use of airspace,and Subpart III, Section 44701, Generalrequirements. Under section 40103, theFAA is charged with prescribingregulations on the flight of aircraft(including regulations on safe altitudes)for navigating, protecting, andidentifying aircraft, and the efficient useof the navigable airspace. Under section44701, the FAA is charged withpromoting safe flight of civil aircraft inair commerce by prescribing regulationsfor practices, methods, and proceduresthe Administrator finds necessary forsafety in air commerce.

This regulation is within the scope of sections 40103 and 44701 because itprescribes aircraft performancerequirements to meet advancedsurveillance needs to accommodateincreases in NAS operations. As moreaircraft operate within the U.S. airspace,improved surveillance performance isnecessary to continue to balance thegrowth in air transportation with theagency’s mandate for a safe and efficientair transportation system.Guide to Terms and AcronymsFrequently Used in This Document

ACI–NA—Airports Council International-North AmericaACSS—Aviation Communication and

Surveillance SystemsADIZ—Air Defense Identification ZoneADS–B—Automatic Dependent Surveillance-

BroadcastADS–C—Automatic Dependent Surveillance-

ContractADS–R—Automatic Dependent Surveillance-

RebroadcastAGL—Above Ground LevelAIA—Aerospace Industries Association of

America

ALPA—Air Line Pilots Association,International

AOPA—Aircraft Owners and PilotsAssociation

ARC—Aviation Rulemaking CommitteeASA—Aircraft Surveillance ApplicationsASAS—Aircraft Surveillance Applications

SystemASDE–X—Airport Surface Detection

Equipment, Model XASSA—Airport Surface Situational

AwarenessATC—Air Traffic ControlCAA—Cargo Airline AssociationCDTI—Cockpit Display of Traffic InformationCNS—Communication, Navigation, and

SurveillanceEAA—Experimental Aircraft AssociationELT—Emergency Locator TransmitterES—Extended SquitterEUROCAE—European Organisation for Civil

Aviation EquipmentEUROCONTROL—European Organisation for

the Safety of Air NavigationFAROA—Final Approach Runway

Occupancy AwarenessFedEx—Federal ExpressFIS–B—Flight Information Service–Broadcast

FL—Flight LevelGA—General AviationGAMA—General Aviation Manufacturers

AssociationGNSS—Global Navigation Satellite SystemGPS—Global Positioning SystemHAI—Helicopter Association InternationalIATA—International Air Transport

AssociationICAO—International Civil Aviation

OrganizationMHz—MegahertzMOPS—Minimum Operational Performance

StandardsMSL—Mean Sea LevelNACP —Navigation Accuracy Category For

Position

NACV —Navigation Accuracy Category forVelocityNAS—National Airspace SystemNBAA—National Business Aviation

AssociationNextGen—Next Generation Air

Transportation SystemNIC—Navigation Integrity CategoryNM—Nautical MileNPRM—Notice of Proposed RulemakingNTSB—National Transportation Safety BoardOPD—Optimized Profile DescentOMB—Office of Management and BudgetRAA—Regional Airline AssociationRAIM—Receiver Autonomous Integrity

MonitoringRFA—Regulatory Flexibility Act

RNP—Required Navigation PerformanceSANDIA—Sandia National LaboratoriesSARPs—Standards and Recommended

PracticesSCAP—Security Certification and

Accreditation ProceduresSDA—System Design AssuranceSIL—Source Integrity LevelSSR—Secondary Surveillance RadarTCAS—Traffic Alert and Collision and

Avoidance SystemTIS–B—Traffic Information Service-

BroadcastTMA—Traffic Management Advisor


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30161Federal Register / Vol. 75, No. 103 / Friday, May 28, 2010/ Rules and Regulations

TSO—Technical Standard OrderUAT—Universal Access TransceiverUPS—United Parcel ServiceURET—User Request Evaluation ToolVFR—Visual Flight RulesWAAS—Wide Area Augmentation System

Table of ContentsI. Background

A. Notice of Proposed RulemakingB. ADS–B Aviation Rulemaking Committee

C. Summary of the Final Rule1. Airspace2. Datalink Requirements3. System Performance Requirements4. Antenna Diversity and Transmit Power

Requirements5. Latency of the ADS–B Out Message

Elements6. Conforming Amendments and Editorial

ChangesD. Differences Between the Proposed Rule

and The Final RuleE. Separation Standards Working Group

II. Discussion of the Final RuleA. Airspace1. 2,500 Feet Above Ground Level

Exclusion in Class E Airspace

2. Airspace for Which ADS–B is Required3. Requests for Deviations From ADS–BOut Requirements

B. Dual-Link Strategy1. Altitude To Require the 1090 MHz ES

Datalink2. Automatic Dependent Surveillance-

Rebroadcast (ADS–R)3. 1090 MHz Frequency CongestionC. Performance Requirements—System1. Performance Requirements Tailored to

Operator, Airspace, or Procedure2. Navigation Accuracy Category for

Position (NAC P )3. Navigation Accuracy Category for

Velocity (NAC V )4. Navigation Integrity Category (NIC)5. Surveillance Integrity Level6. Source Integrity Level (SIL) and System

Design Assurance (SDA)7. Secondary Position SourcesD. Performance Requirements—Antenna

DiversityE. Performance Requirements—Transmit

PowerF. Performance Requirements—Total and

Uncompensated LatencyG. Performance Requirements—Time To

Indicate Accuracy and Integrity ChangesH. Performance Requirements—

Availability1. Preflight Determination of Availability2. System AvailabilityI. Performance Requirements—Continuity

J. Performance Requirements—Traffic

Information Service—Broadcast Integrity(TIS–B)K. Broadcast Message Elements1. NAC P /NAC V /NIC/SDA/SIL2. Receiving ATC Services3. Length and Width of the Aircraft4. Indication of the Aircraft’s Barometric

Pressure Altitude5. Indication of the Aircraft’s Velocity6. Indication if Traffic Alert and Collision

Avoidance System II or AirborneCollision Avoidance System is Installedand Operating in a Mode That MayGenerate Resolution Advisory Alerts

7. For Aircraft With an Operable TrafficAlert and Collision Avoidance System IIor Airborne Collision Avoidance System,Indication If a Resolution Advisory Is inProgress

8. Indication of the Mode 3/A TransponderCode Specified by ATC (RequiresFlightcrew Entry)

9. Indication of the Aircraft’s Call SignThat Is Submitted on the Flight Plan, orthe Aircraft’s Registration Number

(Aircraft Call Sign Requires Flight CrewEntry)10. Indication if the Flight Crew Has

Identified an Emergency, RadioCommunication Failure, or UnlawfulInterference (Requires Flightcrew Entry)

11. Indication of the Aircraft’s ‘‘ IDENT ’’ toATC (Requires Flightcrew Entry)

12. Indication of the Emitter Category13. Indication Whether an ADS–B in

Capability Is Installed14. Indication of the Aircraft’s Geometric

AltitudeL. Ability To Turn Off ADS–B Out

TransmissionsM. Existing Equipment Requirements1. Transponder Requirement

2. Emergency Locator TransmitterRequirementN. Program Implementation1. Timeline2. Financial and Operational Incentives3. Decommissioning Traffic Information

Service-Broadcast (TIS–B)O. SafetyP. Efficiency1. Improved Position Reporting2. Optimized Profile Descents (OPDs)3. Reduced Aircraft Separation4. Expanded Surveillance CoverageQ. ADS–B InR. ADS–B In Applications1. Surface Situational Awareness With

Indications and Alerting

2. In-Trail Procedures3. Interval Management4. Airport Surface Situational Awareness

and Final Approach Runway OccupancyAwareness

S. International HarmonizationT. Backup ATC SurveillanceU. PrivacyV. SecurityW. Alternatives to ADS–BX. ADS–B Equipment Scheduled

MaintenanceY. Specific Design ParametersZ. Economic Issues1. ADS–B Out Equipage Cost2. FAA Cost Savings With ADS–B Out

Compared To Radar

3. Business Case for ADS–B Out and In4. Improved En Route Conflict ProbeBenefit Performance

5. Capacity Enhancements, AirspaceEfficiency, and Fuel Savings Benefits

6. Deriving Benefits From CapstoneImplementation in Alaska

7. Regional Airline Benefits8. General Aviation: High Equipage Costs

With Little BenefitAA. Revisions to Other Regulations

III. Regulatory Notices and AnalysesA. Paperwork Reduction ActB. International Compatibility

C. Regulatory Impact Analysis, RegulatoryFlexibility Determination, InternationalTrade Impact Analysis, and UnfundedMandates Assessment

VI. Executive Order 13132, FederalismVII. Regulations Affecting Intrastate Aviation

in AlaskaVIII. Environmental AnalysisIX. Regulations That Significantly Affect

Energy Supply, Distribution, or UseX. Availability of Rulemaking Documents

I. BackgroundWhile there is currently a drop in air

travel due to a general economicdownturn, delay and congestioncontinue to build in the nation’s busiestairports and the surrounding airspace.The FAA must not only address currentcongestion, but also be poised to handlefuture demand that will surely return asthe nation’s economy improves. TheFAA has been developing the NextGeneration Air Transportation System(NextGen) for the purpose of changingthe way the National Airspace System(NAS) operates. NextGen will allow theNAS to expand to meet future demandand support the economic viability of the system. In addition, NextGen willimprove safety and supportenvironmental initiatives such asreducing congestion, noise, emissionsand fuel consumption through increasedenergy efficiency. for more informationon NextGen, go to http://www.faa.gov/ about/initiatives/nextgen/.

As part of NextGen development, theFAA has determined that it is essentialto move from ground-based surveillanceand navigation to more dynamic andaccurate airborne-based systems and

procedures if the agency is to enhancecapacity, reduce delay, and improveenvironmental performance. AutomaticDependent Surveillance–Broadcast(ADS–B) equipment is an advancedsurveillance technology that combinesan aircraft’s positioning source, aircraftavionics, and a ground infrastructure tocreate an accurate surveillance interface

between aircraft and ATC. It is a keycomponent of NextGen that will moveair traffic control (ATC) from a radar-

based system to a satellite-derivedaircraft location system. ADS–B is aperformance-based surveillancetechnology that is more precise thanradar. ADS–B is expected to provide airtraffic controllers and pilots with moreaccurate information to help keepaircraft safely separated in the sky andon runways. The technology combines apositioning capability, aircraft avionics,and ground infrastructure to enablemore accurate transmission of information from aircraft to ATC.

ADS–B consists of two differentservices: ADS–B Out and ADS–B In.ADS–B Out, which is the subject of this


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1 ADS–R collects traffic information from each broadcast link and rebroadcasts it to ADS–B In-equipped operators on the other broadcast link.This is further explained in section B.2., AutomaticDependent Surveillance-Rebroadcast.

2 TIS–B uses primary and secondary surveillanceradars and multilateration systems to provideproximate traffic situational awareness, includingposition reports from aircraft not equipped withADS–B. TIS–B data may not provide as muchinformation as could be received directly from anaircraft’s ADS–B Out broadcast, because of therequired data processing. The TIS–B signal is anadvisory service that is not designed for aircraftsurveillance or separation, and cannot be used foreither purpose.

3 With FIS–B, aircraft equipped with 978megahertz (MHz) Universal Access Transceiver(UAT) ADS–B In avionics can receive weatherinformation, notices to airmen, temporary flightrestrictions, and other relevant flight information, atno additional cost.

4 A copy of this report is available from the Website http://www.regulations.gov. To find the report,enter FAA–2007–29305–0009.1 in the search field.

5 A copy of this report is available from the Website http://www.regulations.gov. To find the report,enter FAA–2007–29305–0221.1 in the search field

6 An extended squitter is a long message thatMode S Transponders transmit automatically,without needing to be interrogated by radar, toannounce the own-ship aircraft’s presence to nearbyADS–B equipped aircraft or ground based AirTraffic Control.

7 The 1090 MHz ES broadcast link uses the 1090MHz frequency. The UAT broadcast link uses the978 MHz frequency.

rulemaking, periodically broadcastsinformation about each aircraft, such asidentification, current position, altitude,and velocity, through an onboardtransmitter. ADS–B Out provides airtraffic controllers with real-timeposition information that is, in mostcases, more accurate than theinformation available with currentradar-based systems. With moreaccurate information, ATC will be ableto position and separate aircraft withimproved precision and timing.

ADS–B In refers to an appropriatelyequipped aircraft’s ability to receive anddisplay another aircraft’s ADS–B Outinformation as well as the ADS–B Inservices provided by ground systems,including Automatic DependentSurveillance–Rebroadcast (ADS–R), 1 Traffic Information Service–Broadcast(TIS–B), 2 and, if so equipped, FlightInformation Service–Broadcast (FIS–B). 3 When displayed in the cockpit, thisinformation greatly improves the pilot’ssituational awareness in aircraft notequipped with a traffic alert andcollision avoidance system (TCAS)/airborne collision avoidance system(ACAS). Benefits from universalequipage for ADS–B In currently are notsubstantiated, and standards for ADS–BIn air-to-air applications are still in theirinfancy. Thus it is premature to requireoperators to equip with ADS–B In at thistime. This rule, however, imposescertain requirements that will supportsome ADS–B In applications.

As noted in the preamble of theNotice of Proposed Rulemaking (NPRM)associated with this rule, published inthe Federal Register on October 5, 2007(72 FR 56947), Congress enacted the‘‘ Century of Aviation ReauthorizationAct ’’ in 2003. That Act mandated thatthe Secretary of Transportation establisha Joint Planning and DevelopmentOffice (JPDO) to manage NextGen-related work, including coordinating thedevelopment and use of new

technologies for aircraft in the air trafficcontrol system. Since 2006, Congresshas appropriated over $500 million tothe FAA for implementing ADS–B anddeveloping air-to-air capabilities. TheFAA remains committed toimplementing NextGen and adopts thisfinal rule, with some modifications, asdiscussed in further detail below.A. Notice of Proposed Rulemaking

The FAA published the NPRM forADS–B Out in the Federal Register onOctober 5, 2007 (72 FR 56947). Thecomment period for the NPRM wasscheduled to close on January 3, 2008.In response to several commenters, theFAA subsequently extended thecomment period to March 3, 2008 (72FR 64966, Nov. 19, 2007). The FAAreceived approximately 190 commentsto the docket on the NPRM.Commenters included air carriers,manufacturers, associations,Government agencies, and individuals.

B. ADS–B Aviation Rulemaking CommitteeAs part of the rulemaking effort, the

FAA chartered an aviation rulemakingcommittee (ARC) on July 15, 2007, toprovide a forum for the U.S. aviationcommunity to make recommendationson presenting and structuring an ADS–B Out mandate, and to consideradditional actions that may be necessaryto implement its recommendations. TheADS–B ARC submitted its first report,‘‘ Optimizing the Benefits of AutomaticDependent Surveillance–Broadcast, ’’ 4 on October 3, 2007.

The FAA also tasked the ARC to makespecific recommendations concerningthe proposed rule based on thecomments submitted to the docket. TheARC submitted its second report,‘‘ Recommendations on Federal AviationAdministration Notice No. 7–15,Automatic Dependent Surveillance-Broadcast (ADS–B) Out PerformanceRequirements to Support Air TrafficControl (ATC) Service; Notice of Proposed Rulemaking, ’’ 5 to the FAA onSeptember 26, 2008.

To give the public an opportunity tocomment on the recommendationsreceived from the ARC, the FAApublished a notice in the FederalRegister on October 2, 2008 (73 FR57270), reopening the comment periodof the ADS–B Out NPRM docket for anadditional 30 days. The purpose of reopening the comment period was to

receive public comments on the ARCrecommendations only. This commentperiod closed November 3, 2008, withthe FAA receiving approximately 50comments to the ARC’srecommendations. Commentersincluded air carriers, manufacturers,associations, and individuals.

C. Summary of the Final Rule

This final rule will add equipagerequirements and performancestandards for ADS–B Out avionics.ADS–B Out broadcasts informationabout an aircraft through an onboardtransmitter to a ground receiver. Use of ADS–B Out will move air traffic controlfrom a radar-based system to a satellite-derived aircraft location system. Asdiscussed more fully in the sections of this preamble describing equipagerequirements and performancestandards, operators will have twooptions for equipage under this rule—the 1090 megahertz (MHz) extended

squitter6

(ES) broadcast link or theUniversal Access Transceiver (UAT) broadcast link. 7 Generally, thisequipment will be required for aircraftoperating in Classes A, B, and Cairspace, certain Class E airspace, andother specified airspace. See section C.1.‘‘ Airspace ’’ below for additional details.

The NPRM proposed performancerequirements for ADS–B Out to be usedfor ATC surveillance. In addition,several aspects of the proposal would benecessary for future ADS–B Inapplications. The comments to theNPRM and the ARC recommendationsraised significant concerns about theoperational needs and costs of theproposed performance requirements, aswell as the proposed antenna diversityrequirement.

The FAA specifically proposed higherADS–B Out and antenna diversityrequirements than what is needed forATC surveillance to enable certainADS–B In applications. As discussed infurther detail in this document, the FAAhas reconsidered these elements in viewof the comments and has changed theimplementation plan for ADS–B.

The FAA has concluded that this rulewill require only the performancerequirements necessary for ADS–B Out.While certain requirements adopted inthis rule will support some ADS–B Inapplications, the agency is not adopting


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8 These airports are listed in appendix D to part91.

9 These applications include enhanced visualacquisition, conflict detection, enhanced visualapproach, Airport Surface Situational Awareness(ASSA), and Final Approach Runway OccupancyAwareness (FAROA).

10 Extended Squitter Automatic DependentSurveillance–Broadcast (ADS–B) and TrafficInformation Service—Broadcast (TIS–B) Equipment

Operating on the Radio Frequency of 1090Megahertz (MHz).

11 Universal Access Transceiver (UAT) AutomaticDependent Surveillance—Broadcast (ADS–B)Equipment Operating on the Frequency of 978MHz.

12 RTCA, Inc. is a not-for-profit corporationformed to advance the art and science of aviationand aviation electronic systems for the benefit of the public. The organization functions as a FederalAdvisory Committee and develops consensus-basedrecommendations on contemporary aviation issues.The organization’s recommendations are often usedas the basis for government and private sectordecisions as well as the foundation for many FAATSOs. For more information, see http:// www.rtca.org.

13 Minimum Operational Performance Standards

for 1090 MHz Extended Squitter AutomaticDependent Surveillance—Broadcast (ADS–B) andTraffic Information Services—Broadcast (TIS–B).

14 Minimum Operational Performance Standardsfor Universal Access Transceiver (UAT) AutomaticDependent Surveillance—Broadcast.

15 Minimum Operational Performance Standardsfor 1090 MHz Extended Squitter AutomaticDependent Surveillance–Broadcast (ADS–B) andTraffic Information Services–Broadcast (TIS–B).

16 Minimum Operational Performance Standardsfor Universal Access Transceiver AutomaticDependent Surveillance–Broadcast.

17 A number of these items address issues withthe current TSOs.

the higher performance standards thatwould enable all of the initial ADS–B Inapplications. The agency is mindful,and operators are advised, that inaccepting the commenters’ and theARC’s positions regarding antennadiversity and position source accuracy,compliance with this rule alone may notenable operators to take full advantageof certain ADS–B In applications.Operators may voluntarily chooseequipment that meets the higherperformance standards in order toenable the use of these applications.

The following table provides anoverview of the costs and benefits of this final rule.

S UMMARY OF COSTS AND BENEFITS

3% Discount Rate:Low Costs . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. $2.74High Benefits .. ... ... .. ... .. ... .. ... ... . 5.03

Net Benefits-High Benefit/ Low Cost .......................... 2.29

High Costs ... .. ... .. ... .. ... ... .. ... .. .. 5.47Low Benefits ........................... 3.98

Net Benefits-Low Benefits/ High Costs ....................... (1.49 )

7% Discount Rate:Low Costs . ... .. ... ... .. ... .. ... .. ... ... . 2.15High Benefits .. ... ... .. ... .. ... .. ... ... . 2.74

Net Benefits-High Benefit/ Low Cost .......................... 0.59

High Costs ... .. ... .. ... .. ... ... .. ... .. .. 4.11Low Benefits ........................... 2.09

Net Benefits-Low Benefits/ High Costs ....................... (2.02 )

1. AirspaceThis final rule prescribes ADS–B Out

performance requirements for all aircraftoperating in Class A, B, and C airspacewithin the NAS; above the ceiling andwithin the lateral boundaries of a ClassB or Class C airspace area up to 10,000feet mean sea level (MSL); and Class Eairspace areas at or above 10,000 feetMSL over the 48 contiguous UnitedStates and the District of Columbia,

excluding the airspace at and below2,500 feet above the surface.The rule also requires that aircraft

meet these performance requirements inthe airspace within 30 nautical miles(NM) of certain identified airports 8 thatare among the nation’s busiest (based onannual passenger enplanements, annualairport operations count, andoperational complexity) from the

surface up to 10,000 feet MSL. Inaddition, the rule requires that aircraftmeet ADS–B Out performancerequirements to operate in Class Eairspace over the Gulf of Mexico at andabove 3,000 feet MSL within 12 NM of the coastline of the United States.

2. Datalink RequirementsADS–B requires a broadcast link for

aircraft surveillance and to supportADS–B In applications. Operators havetwo options for equipage under thisrule— the 1090 MHz ES broadcast linkor the UAT broadcast link. The 1090MHz ES broadcast link is theinternationally agreed upon link forADS–B and is intended to supportADS–B In applications used by aircarriers and other high-performanceaircraft. The 1090 MHz ES broadcastlink does not support FIS–B (weatherand related flight information) becausethe bandwidth limitations of this linkcannot transmit the large message

structures required by FIS–B. The UAT broadcast link supports ADS–B Inapplications 9 and FIS–B, which areimportant for the general aviation (GA)community.

This final rule requires aircraft flyingat and above 18,000 feet MSL (flightlevel (FL) 180) (Class A airspace) tohave ADS–B Out performancecapabilities using the 1090 MHz ES

broadcast link. This rule also specifiesthat aircraft flying in the designatedairspace below 18,000 feet MSL may useeither the 1090 MHz ES or UAT

broadcast link.

3. System Performance RequirementsWhen activated, ADS–B Out

continuously transmits aircraftinformation through the 1090 MHz ESor UAT broadcast link. The accuracyand integrity of the position informationtransmitted by ADS–B avionics arerepresented by the navigation accuracycategory for position (NAC P ), thenavigation accuracy category forvelocity (NAC V ), the navigation integritycategory (NIC), the system designassurance (SDA), and the sourceintegrity level (SIL).

In the proposed rule, the FAA

referenced the accuracy and integrityrequirements to the appropriate NAC P ,NACV , NIC, and SIL values defined inTechnical Standard Order (TSO)–C166a 10 (for operators using the 1090

MHz ES broadcast link), and TSO–C154b 11 (for operators using the UAT

broadcast link) as the baselinerequirements for ADS–B Outequipment. TSO–C166a adopted thestandards in RTCA, Inc. 12 (RTCA) DO–260A. 13 TSO–C154b adopted thestandards in RTCA DO–282A. 14

After the NPRM was published, theADS–B ARC issued numerousrecommendations in response to publiccomments on the TSOs referenced inthe proposal. Based on the ARCrecommendations and broad industryinput, RTCA revised DO–260A to

become DO–260B 15 and revised DO–282A to become DO–282B. 16 The newRTCA revisions include: (1) Anallowance for transmitting a NIC of 7 onthe surface, (2) procedures for correctlysetting the NAC V , (3) clarifying thelatency requirements, (4) removing thevertical component of NAC P , NAC V ,NIC, and SIL, (5) revising the definitionof SIL to correspond to the definition in

the FAA NPRM, (6) clarifying thedefinition of SIL by dividing it into SILand SDA message elements, (7) creatinga medium power single antenna class,and (8) redefining the bit for the ‘‘ ADS–B In capability installed ’’ messageelement. 17 DO–260B and DO–282B aremore mature standards and fullysupport domestic and internationalADS–B air traffic control surveillance.The updated standards do not increaseperformance requirements.

The FAA updated the TSOs inaccordance with these new RTCAstandards. In addition, the FAA has


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18 Extended Squitter Automatic DependentSurveillance–Broadcast (ADS–B) and TrafficInformation Service–Broadcast (TIS–B) EquipmentOperating on the Radio Frequency of 1090Megahertz (MHz).

19 Universal Access Transceiver (UAT) AutomaticDependent Surveillance–Broadcast (ADS–B)Equipment Operating on the Frequency of 978MHz.

20 Operators with equipment installed that meetsa later version of TSO–C166b or TSO–C154c, asapplicable, are in compliance with this rule.

decided that it is necessary to requirethe new standards contained in TSO–C166b 18 (1090 MHz ES) and TSO–C154c 19 (UAT) as the minimumperformance standards in this finalrule. 20 The updated standardsincorporate multiple changes thataddress public comments and the ARC’srecommendations on the proposal. OnSeptember 11, 2009, the FAAannounced in the Federal Register theavailability of draft TSO–C166b andTSO–C154c for comment (74 FR 46831).The FAA issued final versions of theabove TSOs on December 2, 2009. The

FAA also added additional language in§§ 91.225 and 91.227 stating thatequipment with an approved deviationunder §21.618 also meet therequirements of the rule.

In addition, this final rule specifiesthe performance requirements foraccuracy and integrity (NAC P , NAC V ,and NIC) in meters and nautical milesrather than referencing the numericalvalues used in DO–260B, DO–282B, orthe NPRM. This change translates thevalues but does not alter the actualperformance requirements. The FAAwants to avoid any misinterpretations of

the performance requirements for thisrule, if in the future, RTCA revisesNACP , NAC V , and NIC.

Table 1 summarizes the NAC P , NAC V ,NIC, and SIL values proposed in theNPRM and their equivalentmeasurements, as noted in DO–260Aand DO–282A. Table 2 summarizesNACP , NAC V , NIC, SDA, and SIL valuesas defined in DO–260B and DO–282B.These two tables contain only the valuesapplicable to the NPRM and the finalrule. See DO–260B paragraph 2.2.3 orDO–282B paragraph 2.2.4 for completeinformation on all values.


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21 In the NPRM, SIL was defined as surveillanceintegrity level and represented the maximumprobability of exceeding the NIC containmentradius and a maximum probability of a failurecausing false or misleading data to be transmitted.In this final rule, SIL is referred to as sourceintegrity level and defines the probability of exceeding the NIC containment radius; SDArepresents the probability of transmitting false ormisleading position information.

22 Global navigation satellite system (GNSS) is ageneric term for a satellite navigation system, suchas the Global Positioning System (GPS), thatprovides autonomous worldwide geo-spatialpositioning and may include local or regionalaugmentations.

In this final rule, the NAC P must beless than 0.05 NM. The NAC V and NICvalues are adopted as proposed. TheNACV must be less than 10 meters persecond. The NIC must be less than 0.2NM. The SIL parameter from the NPRMhas been divided into two separateparameters and is discussed in detaillater in this document. 21 In this finalrule, the SDA parameter must be lessthan or equal to 1x10 ¥ 5 per hour,which is equivalent to an SDA of 2, andthe SIL parameter must be less than orequal to 1x10 ¥ 7 per hour or per sample,which is equivalent to a SIL of 3. Globalnavigation satellite system (GNSS)systems 22 will set their SILs based on a1x10 ¥ 7 per-hour probability. Operatorsmust meet these performancerequirements to operate in the airspacewhere ADS–B is required. Any ADS–Bposition source that meets the specifiedperformance standards is acceptable and

complies with the requirements in thefinal rule.4. Antenna Diversity and TransmitPower Requirements

The aircraft antenna is a majorcontributor to ADS–B system linkperformance and an important part of the overall ADS–B Out system. In theNPRM, the FAA proposed an antenna

diversity requirement that wouldsupport ADS–B In applications, such asAirport Surface Situational Awareness(ASSA) and Final Approach RunwayOccupancy Awareness (FAROA).

The FAA has reconsidered the needfor antenna diversity in view of thecomments submitted. The agency hasdetermined that a single bottom-mounted antenna is the minimumrequirement for ATC surveillance.Furthermore, the analysis of ASSA andFAROA does not conclude that antennadiversity is required for theseapplications. As discussed later, theFAA decision to require a NAC P lessthan 0.05 NM signifies that certainADS–B In applications, including ASSAand FAROA, will not be fullysupported.

If future analysis indicates thatantenna diversity is required for ASSAand FAROA, a higher NAC P than thatrequired in this rule also would benecessary to support these applications.The FAA does not adopt antennadiversity as a requirement for ADS–BOut under this rule because it is not

required to support ATC surveillance.Operators must note that this rule doesnot remove or modify any existingantenna diversity requirements fortransponders or TCAS/ACAS.

Aircraft must transmit signals at acertain level of power to ensure groundstations and ADS–B In-equipped aircraftand vehicles can receive the transmittedsignals. As proposed, the final rulerequires UAT systems to broadcast at a16-watt minimum-transmit power, and1090 MHz ES systems to broadcast at a125-watt minimum-transmit power.5. Latency of the ADS–B Out MessageElements

When using an ADS–B system,aircraft receive information from aposition source and process it withonboard avionics. The aircraft’s ADS–Bsystem then transmits position andother information to the ground stationsthrough antenna(s) using either the UATor 1090 MHz ES broadcast link.Generally, latency is the time lag

between the time that positionmeasurements are taken to determinethe aircraft’s position, and the time thatthe position information is transmitted

by the aircraft’s ADS–B transmitter. Thelatency requirements in this final rule,although different from the proposal,represent a more appropriate way toaddress latency. The proposal createdambiguities that are addressed in thesemodifications and are supported by thecommenters. Under this rule, total


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23 The SSWG findings are available from the Website http://www.regulations.gov . The docket numberfor this rulemaking is FAA –2007–29305.

latency cannot exceed 2.0 seconds.Within those 2.0 seconds,uncompensated latency cannot exceed0.6 seconds. Total and uncompensatedlatency are explained in further detail insection II F. ‘‘ PerformanceRequirements—Total AndUncompensated Latency. ’’

6. Conforming Amendments and

Editorial ChangesSection 91.225 requires ADS–B Outfor operations in Class A, B, and Cairspace. In the NPRM, the FAA

inadvertently left out the proposedconforming amendments to §§ 91.130,91.131, and 91.135, which address ClassA, B, and C airspace. This rule amendsthese sections to include the ADS–B Outperformance requirements for theappropriate airspace.

In addition, the regulatory text for§ 91.225 has been reorganized from the

proposed rule language. Therestructuring of the text should makethis section clearer and more reader-friendly.

Lastly, the proposed regulatory texthas been moved from Appendix H tonew §91.227.

All substantive changes to this ruleare fully discussed in Section II,Discussion of the Final Rule.

D. Differences Between the Proposed Rule and the Final Rule

Table 3 summarizes the substantivechanges between the proposed rule andthis final rule. Editorial changes andclarifications are explained elsewhere inthis preamble.

TABLE 3.— S UBSTANTIVE DIFFERENCES BETWEEN THE P ROPOSED RULE AND THE FINAL RULE

Issue area The NPRM— The final rule—

Technical Standard Order .... Proposed performance standards as defined in TSO–C166a (1090 MHz ES) or TSO–C154b (UAT).

Requires performance standards as defined in TSO–C166b (1090 MHz ES) or TSO–C154c (UAT).

Airspace ............................... Proposed requiring all aircraft above FL 240 to transmiton the 1090 MHz ES broadcast link.

Requires all aircraft in Class A airspace (FL 180 andabove) to transmit on the 1090 MHz ES broadcastlink.

Proposed ADS–B performance standards for operationsin all Class E airspace at and above 10,000 feet MSL.

Requires ADS–B performance standards for operationsin Class E airspace at and above 10,000 feet MSL,excluding the airspace at and below 2,500 feet AGL.

NACP .................................... Proposed a NAC P ≥ 9, which provides navigation accu-racy < 30 meters.

Requires NAC P < 0.05 NM.(NACP ≥ 8)

NIC ....................................... Proposed changes in NIC be broadcast within 10 sec-onds.

Requires changes in NIC be broadcast within 12 sec-onds.

SIL ........................................ Proposed a SIL of 2 or 3 ................................................ Requires an SDA of 2.Requires a SIL of 3.

Antenna Diversity ................. Proposed antenna diversity in all airspace specified inthe rule.

Does not require antenna diversity.

Total Latency ....................... Proposed latency in the position source < 0.5 secondsand latency in the ADS–B source < 1 second.

Requires uncompensated latency ≤ 0.6 seconds andmaximum total latency ≤ 2.0 seconds.

Message Elements .............. Proposed a broadcast message element for ‘‘ receivingATC services ’’ .

Does not require a broadcast message element for ‘‘ re-ceiving ATC services. ’’

An ability to turn off ADS–BOut.

Proposed that the pilot be able to turn off ADS–B trans-missions if directed by ATC.

Does not require the pilot be able to disable or turn offADS–B transmissions.

E. Separation Standards Working GroupThe FAA established an internal

Surveillance and Broadcast SystemsSeparation Standards Working group(SSWG) to develop methodologies anddefine metrics as appropriate thatevaluate the end-to-end performance of ADS–B and wide area multilaterationsurveillance systems. These evaluationsinclude investigating the integration of these technologies in conjunction withlegacy surveillance technologies, that is,separation between target positions thatare derived from ADS–B, radar, andwide area multilateration on ATCdisplays.

This SSWG was tasked to perform: (1)Analyses of performance using systemmodels and simulations, including theidentification of key performancedrivers and the development of testscenarios; (2) preliminary evaluationswith prototype system components toenable verification and validation of themodels and as early evidence of systemperformance; and (3) analyses of testresults, operational testing and

dedicated separation standards flighttests for each key-site with fullyfunctional end-to-end systems. Alsoincluded is a test period for each systemwhere performance data is collected onaircraft operating in the surveillanceservice volume.

The SSWG analyses and evaluationsare the basis for most of the performancerequirements specified in this rule. 23

II. Discussion of the Final Rule

Below is a more detailed discussion of the final rule relative to the commentsreceived on the proposal:

A. Airspace

1. 2,500 Feet Above Ground LevelExclusion in Class E Airspace

The NPRM proposed that aircraftmeet ADS–B Out performancerequirements to operate in Class Eairspace at and above 10,000 feet MSL

over the 48 contiguous states and theDistrict of Columbia.Several commenters, including the

DOD and the Experimental AircraftAssociation (EAA), stated that theproposed ceiling of 10,000 feet MSL foraircraft without ADS–B would be amajor hardship and safety issue foraircraft operators flying in mountainousterrain. Commenters and the ARCsuggested that the final rule excludeClass E airspace at and below 2,500 feetabove ground level (AGL), similar to theexclusion in §91.215, ATC Transponderand Altitude Reporting Equipment and

Use.The FAA recognizes the benefit of excluding this airspace in the rule,particularly for visual flight rules (VFR)pilots flying in mountainous areas. Thismodification addresses airspace that isnot affected by the agency’s efforts tomaximize NAS efficiency and capacity.Excluding this airspace from the ruleminimizes any unnecessary financialand operational burdens being placedon aircraft operators who fly inmountainous areas that encroach on


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24 An Air Defense Identification Zone (ADIZ) isan area of airspace over land or water in which theready identification, location, and control of civilaircraft is required in the interest of nationalsecurity.

Class E airspace at and above 10,000 feetMSL, but choose not to equip for theADS–B Out performance standards inthis rule. Consequently, the final ruledoes not require ADS–B performancestandards for operations 2,500 feet AGLand below in Class E airspace at andabove 10,000 feet MSL.

2. Airspace for Which ADS–B Is

RequiredThe NPRM proposed requiring ADS–B performance standards for operationsin most classes of airspace whereoperators currently are required to carrya transponder.

Numerous commenters recommendedthat the FAA limit ADS–B performancerequirements to aircraft operating inClass A airspace only, or Class A and Bairspace only. Several commentersquestioned the proposed ADS–Bperformance requirements in Class Eairspace above 10,000 feet MSL. Manyof these commenters made varying

requests to the FAA concerning theproposed altitude for which ADS–B Outwould be required, including 12,000feet MSL, 15,000 feet MSL, FL 180, andFL 250. The United States ParachuteAssociation noted that skydivingoperations are typically conductedabove 10,000 feet MSL and sometimesconducted in Class A, B, and C airspace.

ADS–B cannot be used for ATCsurveillance if all aircraft are notappropriately equipped. Moreover, it isunreasonable to set up a regulatoryframework and performance standardsthat are based on using two primarysystems for surveillance; nor is itfeasible to fund and maintain two suchsystems. The airspace requirementsspecified in this rule for ADS–B Outmeet ATC surveillance needs.

Class B and C airspace have thehighest volume of air carrier and GAtraffic. They also experience the mostcomplex transitions of aircraft from theen route environment to the terminalarea. With the intricate nature of theairspace, current regulations dictatemore stringent operational requirementsto operate within Class B and C airspaceareas.

In addition, ATC must havesurveillance data for all aircraftoperating in these areas to ensureappropriate situational awareness and tomaximize the use of the NAS. ADS–BOut will enhance surveillance incontrolled airspace areas wheresecondary surveillance radar (SSR)currently exists.

One commenter stated that the FAAshould expand the airspace in whichADS–B is required and specificallyrecommended including Air Defense

Identification Zones (ADIZ) 24 andOffshore Control Area Extensions.

This rule applies to aircraft operatingwithin U.S. airspace, which extends 12NM from the U.S. coast. (The airspacealso includes the Washington, DC,Special Flight Rules Area (SFRA),referred to as an ‘‘ ADIZ ’’ prior to 2009.)Most of the airspace in the ADIZ fallsoutside the 12 NM boundaries.

3. Requests for Deviations From ADS–BOut Requirements

This rule requires operators to broadcast ADS–B Out information whenoperating in specified airspace. If anaircraft is not capable of meeting theperformance requirements, the operatormay request a deviation from the ATCfacility responsible for that airspace.However, as noted in the NPRM, ATCauthorizations may contain conditionsnecessary to provide the appropriatelevel of safety for all operators in theairspace. ATC may not be able to grantauthorizations in all cases for a varietyof reasons, including workload, runwayconfigurations, air traffic flows, andweather conditions.B. Dual-Link Strategy

The NPRM proposed a dual-linkstrategy for ADS–B Out broadcasts.Under the proposal, aircraft operatingabove FL 240 would be required to usethe 1090 MHz ES broadcast link.Aircraft operating below FL 240 and inairspace where ADS–B Out performancerequirements were proposed could useeither the 1090 MHz ES or UAT

broadcast link.

Many commenters suggested that asingle-link system would reduceoperational complexity. Thecommenters noted that the installationand maintenance costs of a dual-linksystem exceed those of a single-linksystem. Some of the commentersproposed a single-link solution butdisagreed over which link should bechosen. Commenters supporting asingle-link UAT system noted that 1090MHz ES does not support FIS–B and isat risk for frequency congestion in afuture air traffic managementenvironment. Commenters supporting asingle-link 1090 MHz ES systemexplained that UAT is notinternationally interoperable andopposed a system that requiresinternational operators to equip with

both links.Boeing noted that most of the NAS

system delays are associated with

arrivals and departures. Therefore,Boeing recommended that the airbornesurveillance functions should provide

benefits at all altitudes and on theground. Ultimately, Boeing commentedthat a single 1090 MHz ES broadcastlink would advance future ADS–B Inapplications at low altitudes.

In mandating ADS–B, the FAA ismindful that some members of the

international air transport communityand the GA community have alreadypurchased ADS–B Out equipment,which use either the 1090 MHz ES orUAT broadcast link. The FAA finds thata dual-link system is necessary for theUnited States to meet the operationalneeds of all NAS operators. Moreover, if the FAA were to require one segment of the aviation community to equip tomeet the needs of another segment of the community, this would presentadditional costs for some operators toequip.1. Altitude To Require the 1090 MHz ESDatalink

Under the proposal, aircraft operatingabove FL 240 would be required to usethe 1090 MHz ES broadcast link.Operators using only the UAT broadcastlink would be limited to operations

below FL 240.The Air Line Pilots Association,

International (ALPA) recommended thatthe FAA require operators to use 1090MHz ES above 18,000 feet MSL to beconsistent with the Class A airspacelower boundary (rather than introduce anew subclassification of establishedairspace). In addition, several GA

commenters requested limiting ADS–Bperformance requirements to only ClassA airspace. The EAA and someindividuals stated that UAT would workjust as well as 1090 MHz ES above FL240 and that aircraft should bepermitted to use exclusively UAT foroperations above FL 240.

The final rule specifies FL 180 (thelower boundary of Class A airspace) asthe ceiling for operating an aircraftequipped only with UAT. Using 1090MHz ES at or above FL 180 provides aclear operational boundary forcontrollers and pilots, and does notcreate conditions of mixed equipage forexisting or future applications. The FAArecognizes that this modification willaffect certain operators that want tooperate above FL 180 and equip onlywith UAT. However, the agencyconcludes that requiring 1090 MHz ESperformance standards for operations inall of Class A airspace is not onlyreasonable for surveillance, but alsoestablishes a baseline for ADS–B In.

The requirement to broadcast 1090MHz ES at and above FL 180 does not


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25 ASA comprises a number of flight-deck-basedaircraft surveillance and separation assurancecapabilities that may directly provide flight crewswith surveillance information and alerts.

26 The service coverage volume for ADS–B Inapplications is explained in greater detail athttp://www.adsb.gov .

27 ADS–B ARC Task II Report to the FAAAppendix N, ADS–R Latency and ReliabilityExpectations (September 26, 2008), available on theWeb site, http:///www.regulations.gov, FAA–2007–29305–0221.1.

28 To date, the requirements for using ADS–B foradvanced iterations of merging and spacing, andself separation have yet to be defined.

29 A copy of this report is available from the Website http://www.regulations.gov . The docket numberfor this rulemaking is FAA–2007–29305.

preclude UAT reception of FIS–Bservices up to FL 240 for aircraft witha dual-link reception capability.

2. Automatic Dependent Surveillance-Rebroadcast (ADS–R)

Under a dual-link strategy, the FAAwill use ADS–R to allow ADS–B In-equipped aircraft using one type of

broadcast link to receive messages aboutaircraft transmitting on the other broadcast link.

Various commenters, including theAir Transport Association of America,Inc. (ATA), Airservices Australia, theAustralia Civil Aviation SafetyAuthority, the Aircraft Owners andPilots Association (AOPA), Boeing,British Airways, and the InternationalAir Transport Association (IATA),expressed concern about a dual-linksystem. Some of these commentersasserted that the need for ADS–Rintroduces additional system-widelatency into the ADS–B system and

poses a single point of failure for thedegradation or loss of surveillance data.In their view, this could limit potentialseparation and efficiency improvementsand affect the air-to-air surveillanceelement of future ADS–B Inapplications. In addition, somecommenters expressed concern aboutthe additional risk of faults or failuresthat could result from translating,merging, and rebroadcasting data fromthe 1090 and 978 MHz frequencies.

Some commenters, including Boeing,contended that ADS–R may not havesufficient growth capability to supportfuture ADS–B In air-to-air applications.Such applications include merging andspacing, self separation, or using ADS–B data to supplement or replace TCAS

because of potential of latency or loopdelays. Rockwell-Collins stated thatADS–R should be able to support manyADS–B In air-to-air applications,including closely spaced parallelapproaches and enhanced visualapproach. It recommended developingADS–R to support more demandingaircraft surveillance applications(ASA). 25

Several commenters, includingAOPA, asserted that the dual-linksystem presents a safety hazard becauseaircraft equipped with different linkscannot ‘‘ see ’’ each other on ADS–B Indisplays in areas without ADS–Rcoverage. The commenters suggestedproviding ADS–R at all public airportswhere a mix of both systems will beencountered.

The FAA is deploying ADS–R in allareas where ADS–B ATC surveillanceexists. 26 ADS–R collects trafficinformation broadcast on the 978 MHzUAT broadcast link and rebroadcaststhe information to 1090 MHz ES users.Similarly, ADS–R collects trafficinformation provided on the 1090 MHzES broadcast link and rebroadcasts theinformation to UAT users. ADS–Rpermits aircraft equipped with either1090 MHz ES or UAT to take advantageof ADS–B In applications.

The FAA disagrees with thecomments suggesting that ADS–Rintroduces safety issues because of theadded latencies attributed to ADS–Rprocessing. ATC automation systems donot require or use ADS–R to providesurveillance. The added latency in therebroadcast of the original ADS–Bmessage are measurably small and donot degrade the reported NAC P , NAC V ,and NIC values. The ARC agreed in itsreport that the latency in ADS–Rprocessing does not degrade thereporting of the position qualityparameters. 27 Latency attributed toADS–R does not compromise the safetyof the initial ADS–B In applications.

The intended functions of ADS–B, asidentified in the NPRM, are notcompromised by the latency introducedwith rebroadcasting the messages.However, future ADS–B In applicationsnecessarily may be limited becauseof the latency associated with ADS–R. 28 The FAA has a strong interest inproviding the option for operators toequip with UAT, so they may benefitfrom FIS–B service. In making thedecision to use a dual-link strategy, theFAA acknowledged and weighed thefact that potential benefits of futureapplications may not be fully realized

based on this decision. In situationswhere an airport is not within theplanned ADS–B coverage area, theairport will not have ADS–R coverage.Consequently, an aircraft with ADS–BIn will not have the benefit of ADS–R,and ADS–B In will not provideawareness of aircraft that are

broadcasting on a different broadcastlink.

If an aircraft leaves the ADS–Bcoverage area, there will be anindication to the pilot that the aircraftis no longer within range of ADS–R

service. In this case, the pilot needs tomaintain separation in the same mannerdone today, which is relying on visualscanning and directions from ATC. TheFAA will ensure that the dual-linkstrategy does not impact safety as futureapplications are developed.3. 1090 MHz Frequency Congestion

Boeing, Federal Express (FedEx), and

IATA suggested that the FAA assessfuture 1090 MHz frequency congestion.The ARC supported the dual-linkstrategy, but recommended that the FAAstudy the necessary mitigations of 1090MHz frequency congestion. The ARCspecifically recommended that thesemitigations ensure 1090 MHz ES isinteroperable with ACAS and SSR,while providing sufficient air-to-airrange to support NextGen ADS–B Inapplications.

Congestion on the 1090 MHzfrequency is a risk shared by TCAS/ACAS and SSR systems using the ModeS transponder. The FAA conducted astudy to assess 1090 MHz frequencycongestion in the future air trafficenvironment. 29 The FAA is analyzingalternatives and will enact the necessarymitigations to reduce the 1090 MHzfrequency congestion risk for ADS–B,TCAS, and SSR, while enabling rangesappropriate for many ADS–B Inapplications through 2035.C. Performance Requirements—System

While some commenters supportedthe proposed performance requirements,numerous organizations and individualscommented that the performance

requirements generally were toostringent, unnecessary, and would entailan undue economic burden onoperators.1. Performance Requirements Tailoredto Operator, Airspace, or Procedure

The NPRM proposed specificperformance requirements for ADS–BOut. Several commenters, including theAerospace Industries Association of America (AIA), Boeing, the DOD, EAA,Honeywell, Lockheed Martin, and theARC, asked the FAA to tailor the ADS–B performance requirements based onspecific application requirements orairspace.Lockheed Martin and the DOD notedthat some military aircraft may not meetthe proposed equipage requirementsand would need accommodations tooperate in ADS–B Out-designatedairspace. One commenter wasconcerned that the DOD was exemptfrom the proposed requirements.


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30 ADS–B ARC Task II Report to the FAA 6(September 26, 2008), available on the Web site,http://www.regulations.gov, FAA–2007–29305–0221.1.

31 ASDE–X is a traffic management system for theairport surface that provides seamless coverage andaircraft identification to air traffic controllers. Thesystem uses a combination of surface movementradar and transponder multilateration sensors todisplay aircraft position.

32 ADS–B ARC Report to the FAA Appendix P,Programmatic Decision Analysis (September 26,2008), available at http://www.regulations.gov,FAA–2007–29305–0221.1.

33 A copy of the Separation Standards WorkingGroup report is available from the Web site http:// www.regulations.gov. The docket number for thisrulemaking is FAA–2007–29305.

The FAA has determined that it is notoperationally feasible to assign differentperformance requirements dependenton the nature of the operation. It wouldnot be effective to require both pilotsand controllers to verify specificperformance parameters before anygiven operation or change of airspace.Therefore, the FAA is specifyingminimum performance requirements forall ADS–B Out-equipped aircraft tooperate in certain designated airspace.

No special allowance is made in thisrule to relieve the military from thesame performance requirements as thecivilian aviation community. The FAArecognizes that the DOD and otherFederal agencies are NAS users, andneed access to all areas of the NAStoday and in the future. This ruleprovides procedures for an aircraft thatdoes not meet the ADS–B Outperformance requirements, i.e., to obtainan ATC authorized deviation to operatein the airspace for which ADS–B is

required. The FAA will collaborate withthe appropriate U.S. Governmentdepartments or agencies (including butnot limited to DOD, and the Departmentof Homeland Security) to developMemorandums of Agreement toaccommodate their National defensemission requirements while supportingthe needs of all other NAS users.

2. Navigation Accuracy Category forPosition (NAC P )

The NPRM proposed requiring aNACP greater than or equal to 9. This isequivalent to horizontal positionaccuracy of less than 30 meters andvertical position accuracy of less than45 meters. A NAC P of less than 30meters horizontal would support ATCsurveillance, ASSA, FAROA, and otherfuture ADS–B In applications.

Airbus, ATA, AviationCommunication and SurveillanceSystems (ACSS), Boeing, Rockwell-Collins, United Airlines, and UnitedParcel Service (UPS) questioned thenecessity of a NAC P greater than orequal to 9. The ARC recommended thatthe FAA institute NAC P requirements

based on domains of airspace defined bydifferent types of operations, withminimum NAC P values ranging from 5through 9. 30 The ARC alsorecommended that when a NAC P greaterthan or equal to 9 is necessary, operatorsshould only be required to equip witha position source that could meet aNACP greater than or equal to 9 for 95percent of an hour and meet a NAC P

greater than or equal to 8 for 99.9percent of an hour.

Boeing commented that there is noneed for vertical accuracy becauseneither ATC nor any of the initial ADS–B In applications require it. The ARCrecommended that the FAA not applythe vertical position accuracyrequirement associated with a NAC P of 9 for surface operations. The ARC also

recommended that the FAA modify thedefinition of a NAC P of 9 in DO–260Aand DO–282A. This modification wouldremove the vertical accuracyrequirement if the aircraft is on thesurface.

The FAA reviewed these commentsand the necessary requirements for theADS–B Out and ADS–B In applicationsthat are contemplated today. A NAC P of less than 0.05 NM is required for ATCsurveillance. A NAC P of less than 30meters is required only for ASSA andFAROA. Because surface surveillance

benefits enabled by ADS–B will only befully available where Airport SurfaceDetection Equipment, Model X (ASDE–X) systems, 31 and ADS–R and TIS–B arein use, the FAA has reconsidered theuniversal requirement of a NAC P of lessthan 30 meters.

While the higher NAC P wouldsupport a limited number of ADS–B Inapplications, it could also increasecosts 32 to all operators required to meetthe ADS–B performance standards.Therefore, this final rule reduces theposition accuracy reporting requirementand adopts a NAC P of less than 0.05NM. This NAC P requirement applies toall aircraft operating in the airspace

identified in this rule.In addition, the FAA considered thecomments regarding the verticalaccuracy component of NAC P . As thereare no ATC separation servicesrequirements for vertical accuracy orintegrity, the FAA has removed thevertical accuracy and integrityrequirement from NAC P , NAC V , NIC,and SIL in TSO–C154c and TSO–C166b.3. Navigation Accuracy Category forVelocity (NAC V )

The NPRM proposed requiring aNACV greater than or equal to 1, whichis equivalent to velocity accuracy of lessthan 10 meters per second.

The European Organisation for theSafety of Air Navigation

(EUROCONTROL) commented that aNACV of 1 is not sufficient for ATCservices or advanced ADS–B Inapplications. The ARC recommendedthat NAC V should not be required.

Different air navigation serviceproviders may need differentperformance requirements dependingon the airspace in which theyimplement ADS–B separation services.The FAA reviewed this requirement andconcludes that a NAC V is required forseparation services in the United States.The agency modeled and calculated theNACV requirements for aircraftseparation, using assumptions unique tothe U.S. environment. Based on thisanalysis, the FAA determined that ahorizontal velocity accuracy of less than10 meters per second, as proposed inthe NPRM, is required for ATCsurveillance within the NAS. 33 Therefore, this requirement is adoptedas proposed.

4. Navigation Integrity Category (NIC)The NPRM proposed requiring a NIC

greater than or equal to 7, whichprovides navigation integrity of lessthan 0.2 NM. Boeing questioned thenecessity of this requirement. The ARCrecommended that the FAA adopt NICrequirements based on airspace, withminimum NIC values ranging from 0 to7.

The FAA reviewed this requirementand determined that a NIC of less than0.2 NM is necessary for ATC separationservices, particularly in the approach

environment. Similar to the NAC P, it isnot practical to assign different NICvalues based on types of airspace.Therefore, this rule requires a NIC of less than 0.2 NM.

5. Surveillance Integrity Level

The FAA’s proposal for surveillanceintegrity level stated that thesurveillance integrity level is based on

both the design assurance level of theADS–B Out avionics and the positionsource. Several commenters, includingRockwell-Collins, pointed out that theproposed definition was inconsistent

with the surveillance integrity leveldefinition provided in DO–260A.Commenters stated that DO–260AChange 2 defined surveillance integritylevel as including only the positionsource. The ARC recommended that theFAA use the definition of surveillanceintegrity level found in RTCA DO–


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34 Minimum Aviation System PerformanceStandards (MASPS) for Aircraft SurveillanceApplications (ASA).

35 GPS is a U.S. satellite-based radio navigationsystem that provides a global-positioning service.

36 ADS–B ARC Task II Report to the FAAAppendix T, Antenna Diversity Comments on Cost,(September 26, 2008), available at http:// www.regulations.gov, FAA–2007–29305–0221.1.

289, 34 which also limited the designassurance to the position source.

The FAA asserts that the designassurance of the ADS–B system needs torepresent the complete system, and nota single piece of that system, to provideair traffic separation services. The FAAagrees that the inconsistency betweenthe proposed rule and the RTCAstandard is unworkable; however, RTCAhas updated the design assurancerequirements in DO–260B and DO–282Bto include the entire ADS–B avionicssystem, rather than just the positionsource. The ADS–B system includesADS–B transmission equipment, ADS–Bprocessing equipment, position source,and any other equipment that processesthe position data transmitted by theADS–B system. The DO–260B change isconsistent with the rule.

6. Source Integrity Level (SIL) andSystem Design Assurance (SDA)

In DO–260A (TSO–C166a) and DO–

282A (TSO–C154b), SIL was defined assurveillance integrity level and represented two separate components:(1) The maximum probability of exceeding the NIC containment radiusand (2) a maximum probability of afailure causing false or misleading datato be transmitted. DO–260B (TSO–C166b) and DO–282B (TSO–C154c)separate these two components into twodistinct parameters. SIL is now referredto as source integrity level and definesthe maximum probability of exceedingthe NIC containment radius; SDA nowdefines the maximum probability of afailure causing false or misleading datato be transmitted.

The FAA proposed a SIL value of 2 or 3. A SIL of 2, as stated in TSO–C166aand TSO–C154b, represented: (1) Amaximum probability of exceeding theNIC containment radius of 1x10 ¥ 5 perhour or per sample; and (2) a maximumprobability of a failure causing false ormisleading data to be transmitted of 1x10 ¥ 5 per hour.

A SIL of 3 represented: (1) Amaximum probability of exceeding theNIC containment radius of 1x10 ¥ 7 perhour or per sample and (2) a maximumprobability of a failure causing false or

misleading data to be transmitted of 1x10 ¥ 7 per hour.The FAA proposed these two values

for SIL because its separation standardsmodeling determined that theprobability of exceeding the NICcontainment radius must be less than1x10 ¥ 7 per hour or per sample and theprobability of a failure causing false or

misleading data must be less than1x10 ¥ 5 per hour. The FAA’s TSOs andthe corresponding RTCA documents didnot allow for this combination.

Therefore, in developing and issuingthe NPRM, the FAA assumed that mostoperators, in upgrading their equipmentfor ADS–B, would equip with a globalpositioning system (GPS) 35 that wouldprovide a NIC containment radius of 1x10

¥7 per hour (a SIL of 3). However,to require the associated maximum

probability of failure causing false ormisleading data to be transmitted at1x10 ¥ 7 per hour was not onlyunreasonable but also unnecessary.Therefore, the FAA proposed that a SILof 2 was also acceptable.

With the separate SIL and SDA valuesavailable under DO–260B and DO–282B, the rule requires a maximumprobability of exceeding the NICcontainment radius of 1x10 ¥ 7 per houror per sample (which equates to a SILof 3), and a maximum probability of

1x10¥ 5

per hour of a failure causingfalse or misleading data to betransmitted (which equates to an SDA of 2).

Changing the proposed probability of exceeding the NIC containment radiusfrom 1x10 ¥ 5 per hour or per sample to1x10 ¥ 7 per hour or per sample shouldnot impact NAS users. This is becausecurrently available ADS–B Out systemsusing GNSS will provide an integritymetric based on 1x10 ¥ 7 per hour.

7. Secondary Position SourcesThe General Aviation Manufacturers

Association (GAMA), IATA, andRockwell-Collins commented that thefinal rule should specify separateperformance requirements for secondaryposition sources in the event that theirprimary position source is unavailable.

The FAA disagrees that a separate setof requirements is necessary forsecondary position sources because therule does not require a secondarysource. The NAC P , NAC V , NIC, SDA andSIL requirements in this rule applyregardless of the position source in use.

D. Performance Requirements—Antenna Diversity

The NPRM proposed that aircraftmeet optimum system performance byequipping with both a top and a bottomantenna to support ADS–B Inapplications.

Several commenters, includingAOPA, did not support this aspect of the proposal because antenna diversitysignificantly increases the cost of ADS–B. AOPA also noted that historical

TCAS and transponder use does notindicate that dual antennas arenecessary.

Airservices Australia and theAustralia Civil Aviation SafetyAuthority noted that Australia is notrequiring antenna diversity for GAaircraft. The ARC recommendedallowing non-diversity antennainstallations for VFR aircraft flyingthrough Class B and C airspace and

below 15,000 feet MSL (1090 MHz ES)or below 18,000 feet MSL (UAT), butnot landing at a primary airport. TheARC also recommended that the FAAundertake further studies to assess andvalidate the need for antenna diversityin low-altitude airspace.

The FAA proposed dual antennas tosupport ADS–B Out and ADS–B In air-to-air applications. For ATCsurveillance, only a single bottom-mounted antenna is necessary. Thecommenters and the ARC identified thiselement of the proposal as requiring

significant costs for the GA operators.36

The FAA has reconsidered its initialstrategy for launching the ADS–Brequirements and is adopting theperformance standards necessary forATC surveillance. Therefore, this ruledoes not require antenna diversity forADS–B to operate in any airspace. Thischange does not alter or affect antennadiversity requirements for other aircraftsystems, such as transponders or TCASII.

Operators should be aware that a dualantenna installation could provideadditional benefits that are not includedin the scope of this rule. Airport surfacesituational awareness or alertingapplications may be compromised by asingle-antenna installation. Operatorswho equip with a single antenna maynot be able to accrue all available

benefits from some or all future ADS–B In applications.

While requirements for theseapplications have not yet been fullydefined, modeling performed by boththe ARC and the FAA has indicated thata single antenna may not be able toperform adequately for surfaceapplications. If the FAA, for example,issues a future mandate requiringsurface performance capability,operators of single-antenna-equippedaircraft may need to upgrade theavionics installed on their aircraft.

Operators should also be aware thatsingle-antenna installations are not ascapable as dual-antenna installations of receiving ADS–B messages in an


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37 The commenters specifically referenced theRTCA Airborne Surveillance ApplicationsMinimum Aviation System Performance Standardsand DO–303 Safety ‘‘ Safety, Performance andInoperability Requirements Document of the ADS–B Non-Radar-Airspace (NRA) Application. ’’

environment with a highly congestedspectrum. Because of increasingcongestion on the 1090 MHz frequencyover time, single-antenna installationsof ADS–B may not be able to achieve thesame range for ADS–B In applications asaircraft with two antennas.

This limitation on the upper bound of ADS–B In application range for single-antenna installations does not impact

any of the application benefits cited inthis rule. The FAA is actively pursuingstrategies to mitigate spectrumcongestion concerns of the 1090 MHzfrequency. However, operatorsemploying the 1090 MHz ES broadcastlink should be aware that future air-to-air applications that require longerrange reception may require dualantennas or a UAT system.E. Performance Requirements—Transmit Power

The NPRM proposed that aircraftequipped with UAT would have aminimum 16-watt transmit powerperformance and aircraft equipped with1090 MHz ES would have a minimum125-watt transmit power performance.Some commenters, particularly AOPA,argued that the proposal was notwarranted and imposed unnecessaryexpense. The ARC commented thatusing the existing power level withoutantenna diversity may provide theperformance needed to make broaderuse of non-diversity antennainstallations.

The FAA has determined thatreducing the transmit powerrequirement would significantly impact

the ground infrastructure. The FAA willrely on a series of approximately 800ground stations to provide ATCseparation services throughout theUnited States. The ground stations will

be placed 150 to 200 miles apart andwill require the minimum aircraftoutput power specified in the rule toensure coverage. Lowering the aircraftoutput power requirements, assuggested by the commenters, wouldrequire the FAA to expand and redesignthe ADS–B ground infrastructure.Consequently, the power levels remainunchanged in the final rule.

F. Performance Requirements—Total and Uncompensated Latency

In the NPRM, the FAA proposed todefine latency as the time informationenters the aircraft through the aircraftantenna(s) until the time it istransmitted from the aircraft. The FAAfurther proposed that the navigationsensor should process informationreceived by the aircraft’s antenna(s) andforward this information to the ADS–B

broadcast link avionics in less than 0.5

seconds. The processed informationthen would be transmitted in the ADS–B message from the ADS–B Out

broadcast link avionics in less than 1.0second from the time it was receivedfrom the navigation sensor.

Several commenters, includingAirbus, Boeing, EUROCONTROL,GAMA, and Honeywell, commentedthat the latency requirements are not

well defined, are too stringent, and arenot consistent with other standards. 37 United Airlines and UPS recommendedthat the FAA specify the accuracy of position information at the time of transmission. Boeing and Honeywellrecommended that the FAA specifylatency, based on the time of applicability of the position source.

The ARC stated that the FAA should:(1) Specify latency requirements at theaircraft level, not the equipment level;(2) specify the maximumuncompensated latency to minimize oreliminate installation wiring changes of existing ADS–B Out implementations,while meeting ATC surveillancerequirements; (3) specify total latencyand uncompensated latency; and (4)reference latency to the time of applicability of the position provided bythe position sensor, rather than the timeof measurement.

The FAA adopts three of the four ARCrecommendations. First, the FAA agreesthat latency must be defined at theaircraft level and not the equipmentlevel. Second, the latency requirementsare set at the maximum value that willallow ATC surveillance. Although thelatency requirements will drive wiring

changes in some aircraft, therequirements will minimize the numberof aircraft affected to the maximumextent possible. Third, the FAA hasdefined the latency requirements astotal latency and uncompensatedlatency. The FAA does not agree withthe fourth recommendation to measurelatency at the time of applicability. Todo so would place latency requirementsonly on part of the overall system andspecifically exclude the position sourcelatency. Since the entire system’slatency, including the position source,must be limited to ensure accuracy of

the transmitted position the rulerequires latency to be measured fromthe position source time of measurement and not the time of applicability.

This rule specifies two separatelatency requirements: Total latency and

uncompensated latency. Total latency isdefined as the time between whenmeasurements are taken to determinethe aircraft’s geometric position(latitude, longitude, and geometricaltitude) and when the ADS–Btransmitter broadcasts the aircraft’sposition. Under this rule, the totallatency cannot exceed 2.0 seconds.Latency is compensated to account forthe movement of the aircraft while theunit is processing the positioninformation. The avionics usuallycompensate latency based on velocity

but may also compensate based onacceleration.

Uncompensated latency is defined asthe time the avionics does notcompensate for latency. Under this rule,within the 2.0 second total latencyallocation, a maximum of 0.6 secondsmay be uncompensated latency. Theavionics must compensate for anylatency above 0.6 seconds up to themaximum of 2.0 seconds byextrapolating the position to the time of transmission.

Aircraft velocity, as well as positionaccuracy and integrity metrics (NAC P ,NACV , NIC, SDA, and SIL), must betransmitted with their associatedposition measurement, but are notrequired to be compensated.G. Performance Requirements—Time ToIndicate Accuracy and Integrity Changes

The NPRM proposed that changes inNIC and NAC P must be broadcast within10 seconds. This proposed requirementwould bind the latency of the NIC and

NACP , however this requirement wouldalso bind the maximum amount of timean integrity fault can exist without anindication, as an integrity fault isindicated by changing the NIC andNACP to zero.

The ARC, GAMA, and Rockwell-Collins commented that 10.0 seconds isnot enough time to indicate a change inthe NIC. They specifically noted thatGNSS position sources use the entire10-second allocation, which does notallow time for the ADS–B equipment toactually transmit the change. Rockwell-Collins, GAMA, and the ARCrecommended instead that changes inNIC and SIL be broadcast within 12.1seconds.

Position sources typically provide anaccuracy and integrity metric with eachposition that is output. To allow GNSS-

based position sources time to detectand eliminate possible satellite faults,GNSS systems allow the integrity metricassociated with a position to actually lag

behind the output of the position. TSO–C145/146 and TSO–C196 GNSS systemshave up to 8.0 seconds to alert to an


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38 RTCA DO–229, Minimum OperationalPerformance Standards for Global PositioningSystem/Wide Area Augmentation System AirborneEquipment, defines the availability of a navigationsystem as the ability of the system to provide therequired function and performance at the initiationof the intended operation. Availability is anindication of the ability of the system to provideusable service with the specified coverage area.Signal availability is the percentage of time thatnavigational signals transmitted from externalsources are available for use. Availability is afunction of both the physical characteristics of theenvironment and the technical capabilities of thetransmitter facilities.

39 WAAS is a U.S. wide-coverage augmentationsystem to GPS that calculates integrity andcorrection data on the ground and usesgeostationary satellites to broadcast the data to GPS/SBAS (Satellite-Based Augmentation System (non-U.S.)) users.

40 Required Navigation Performance (RNP) is astatement of the total aircraft navigationperformance necessary for operation within adefined airspace.

41 DO–229 defines the continuity of the system asthe ability of the total system (comprising allelements necessary to maintain aircraft positionwithin the defined airspace) to perform its functionwithout interruption during the intended operation.More specifically, continuity is the probability thatthe specified system performance will bemaintained for the duration of a phase of operation(presuming that the system was available at the

beginning of that phase of operation), and predictedto exist throughout the operation.

integrity fault. TSO–C129 systems donot have an overarching integrity faulttime-to-alert requirement, but they dohave navigation mode specific integrityfault time-to-alert requirements.Specifically, TSO–C129 systems mustindicate an integrity fault within 10seconds in terminal and approachmodes.

The requirement to indicate a change

in NIC applies to the time betweenwhen a fault-free NIC is transmittedwith a faulted position and when theNIC is updated to indicate the fault.Thus, the clock to indicate the changein NIC does not start at the onset of thefault, but rather at the broadcast of thefaulted position from the ADS–Bsystem. Thus, the total time to updatethe NIC is based on the cumulativeeffect of—(1) the position source faultdetection and exclusion time, and (2)the worst-case asynchronoustransmission difference between whenthe fault-free NIC with faulted positionis transmitted and when the faulted NICis transmitted.

The FAA reviewed the separationstandards work to determine if a 12.0second delay in the broadcast of anintegrity fault would impact separationstandards. The FAA found that noexisting terminal and en routesurveillance standards would beimpacted with a 12.0 second delay, andthus the rule requires that changes inNIC be broadcast within 12.0 seconds.

The ARC, GAMA, and Rockwell-Collins also commented that changes inNACP , NAC V , and SIL should be

broadcast within 3.1 seconds versus

10.0 seconds. The FAA determined thatthere is no basis to tighten therequirement. Therefore, the 10.0 secondrequirement applies to indicatingchanges in NAC P , NAC V , SDA, and SIL.H. Performance Requirements—Availability

The FAA did not propose anyavailability 38 requirements for this rule.The proposed rule generated multiplecomments concerning statements in thepreamble regarding availability andwhether the FAA should requireoperators to accomplish a preflight

determination of GNSS availability.Other commenters focused on aperceived requirement for operators toequip with avionics that had a systemavailability equivalent to Wide AreaAugmentation System (WAAS) 39 .1. Preflight Determination of Availability

The proposal preamble explained that

operators must verify ADS–B Outavailability before flight as part of theirpre-flight responsibilities. This issimilar to the requirement for preflightdetermination of availability for certainRequired Navigation Performance(RNP) 40 operations.

ATA argued that the process todetermine availability could be timeconsuming for operators and that theFAA should provide furtherjustification. Boeing stated that theNPRM did not include an availabilityrequirement; therefore, the FAA shouldcorrect its statement in the NPRMpreamble advising operators to makethis part of their preflight actions.

The ARC recommended that the FAAprovide preflight prediction systemsthat assess the ability of typicalpositioning sources to meet the positionaccuracy and integrity requirements.

This rule requires operators to meetthe adopted minimum position accuracyand integrity performance requirementsto operate in the airspace described inthe rule. To facilitate compliance withthe rule and assist pilots for the flightplanning, the FAA will provide apreflight availability prediction service

by 2013. Therefore, prior to departure,

operators should verify that thepredicted performance requirementswill be met for the duration of the flight.This service will determine whetherGNSS equipment is capable of meeting§ 91.227 position accuracy and integrityrequirements for operating in theairspace defined in this rule. Operatorsmay also use their own preflightavailability prediction tools, providedthe predictions correspond to theperformance of their equipment. TheFAA advises operators to consultmanufacturers’ information on specificavionics and prediction services.

2. System AvailabilityNumerous commenters, including the

DOD, contended that the proposal

required WAAS (or implied that thepositioning service used by the aircrafthave an availability equivalent toWAAS.)

As stated in the NPRM, operators mayequip with any position source.Although WAAS is not required, at thistime it is the only positioning servicethat provides the equivalent availabilityto radar (99.9 percent availability). The

FAA expects that future positionsources such as GNSS using the L5 GPSsignal, GPS using Galileo signals, andGPS tightly integrated with inertialnavigation systems will also provide99.9 percent availability. Operators whoequip with other position sources, suchas non-augmented GPS, may experienceoutages that limit their access to theairspace defined in this rule.

If an aircraft’s avionics meet therequirements of this rule butunexpected GPS degradations duringflight inhibit the position source fromproviding adequate accuracy (within0.05 NM) and integrity (within 0.2 NM),ATC will be alerted via the aircraft’s

broadcasted data and services will beprovided to that aircraft using the

backup strategy. An aircraft that is notequipped to meet the requirements of this rule will not have access to theairspace for which ADS–B is required.The FAA notes that preflight availabilityverification eliminates any need for thesystem to meet a specified availabilityrequirement upon installation.I. Performance Requirements—Continuity

The FAA did not propose a

continuity41

requirement in the NPRM.Several commenters, including Airbus,GAMA, Rockwell-Collins, and the ARC,suggested that the FAA add a continuityrequirement. These commenters arguedthat such a requirement would ensurethat an aircraft could continueproviding the ADS–B informationthroughout a flight.

Aircraft are to meet the performancerequirements for the duration of theoperation, not just a portion of theflight. The FAA’s preflight availabilityprediction service will help pilotsensure that the aircraft can continuetransmitting ADS–B informationthroughout their planned flight, basedon expected operations. Unexpected


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42 ASDE–3 is an airport radar that shows to towercontrollers the location of aircraft on the surface.

failures will be accommodated, asdescribed in the discussion onavailability; therefore, there is no needfor a separate continuity requirement.

J. Performance Requirements—TrafficInformation Service—Broadcast Integrity (TIS–B)

The NPRM did not propose anychanges to the standards for TIS–B.Boeing stated that the FAA’s plans toimplement TIS–B with a SIL of 0 wouldseverely limit its utility for ADS–B Inapplications. Boeing recommended thatthe FAA change TIS–B to provide a SILof 2 or greater, to be consistent with theSIL proposed for ADS–B Out.Honeywell commented that a TIS–Bintegrity level should be established forvalue-added, near-term applications.The ARC did not specifically commenton the TIS–B SIL, but did recommendthat the FAA include a discussion of theFIS–B and TIS–B benefits in thepreamble to the ADS–B Out final rule.

The TIS–B system is expected tosupport four of the five initial ADS–B Inapplications. The FAA acknowledgesthat future ADS–B In applications mayrequire improved representation of theposition integrity metrics. With the SILand SDA changes incorporated in DO–260B and DO–282B and possiblechanges to future versions of DO–317,the FAA plans, outside of thisrulemaking effort, to evaluate theusefulness of the broadcast of integrityparameters from TIS–B.

K. Broadcast Message Elements

1. NAC P /NAC V /NIC/SDA/SILThe NPRM did not specifically

propose NAC P , NAC V , NIC, or SIL as broadcast message elements in section 4of appendix H to part 91, MinimumBroadcast Message Element Set forADS–B Out. These requirements werespecified in section 3 of appendix H topart 91, ADS–B Out PerformanceRequirements for NIC, NAC, and SIL.

Honeywell noted that NAC P , NAC V ,NIC, and SIL are required messageelements in DO–260A.

To resolve any questions, the FAA hasrepeated the indications for these

elements in §91.227(d)(16) through (19).In addition, and consistent with TSO–C166b and TSO–C154c, SIL and SDAare listed as separate values.

2. Receiving ATC ServicesThe NPRM proposed requiring the

message element ‘‘ Receiving ATCServices. ’’ Several commenters,including ACSS, Airbus, Boeing,EUROCONTROL, United Airlines, andUPS, commented that this messageelement is unnecessary and poorly

defined. UPS and United Airlinessuggested that the FAA use the groundautomation system to accomplish thefunction of this message element. Somecommenters also contended that thismessage element could require anadditional user interface, which is notavailable on current equipment.

The ARC recommended that the FAAclarify the definition of this messageelement and explain how it can beimplemented without pilot entry. TheARC also requested that the FAAresearch whether both ‘‘ Receiving ATCServices ’’ and ‘‘ Mode 3/A Code ’’ arenecessary.

The FAA concludes that ‘‘ ReceivingATC Services ’’ is not necessary for ATCsurveillance because this informationcan be directly inferred from the Mode3/A code. Furthermore, this messageelement could increase costs for anadditional user interface. Therefore, thisrule does not include ‘‘ Receiving ATCServices ’’ as a required broadcast

message element.3. Length and Width of the Aircraft

The NPRM proposed requiring amessage element to broadcast the lengthand width of the aircraft.

Airbus and EUROCONTROLcommented that length and widthinformation is not necessary forsurveillance or airborne ADS–B Outapplications. Airbus and an individualcommenter noted that length and widthinformation should be quantifiedrelative to the aircraft position referencepoint or to a known offset.

GAMA and Rockwell-Collins notedthat the TSOs allow some aircraft tocontinuously transmit ‘‘ in-air ’’ becausethese aircraft do not have a means todetermine their air/ground status.Rockwell-Collins commented that therule should require all aircraft to assesstheir air/ground status and broadcast theappropriate set of messages for thatstatus. The ARC recommended that theFAA address this issue in the preambleto the final rule.

The FAA notes that TSO–C154c andTSO–C166b allow the operator todetermine whether to transmit theaircraft’s latitude and longitudereferenced to the GPS antenna locationor the ADS–B position reference point.The ADS–B position reference point isthe center of a box, based on the aircraftlength and width. With the positionoffset to the ADS–B reference point, theADS–B is able to report the position of the edges of the aircraft. This rule doesnot require operators to apply theposition offset because ATCsurveillance does not require a positionoffset.

The FAA concludes that therequirement to transmit aircraft lengthand width is necessary because thismessage element will be used as aninput for ASDE–X systems and allowsthe FAA to decommission ASDE–3radars 42 that interface with ASDE–X, aswell as the surface movement radarsystems that are at certain ASDE–X siteswithout ASDE–3. The length-widthcode will be preset when ADS–Bequipment, meeting the standards inTSO–C154c or TSO–C166b, is installedin the aircraft.

ADS–B equipment transmits anairborne position message when theaircraft is airborne, and a surfaceposition message when the aircraft is onthe ground. Aircraft automaticallydetermine airborne or ground status andtransmit the appropriate message. Foraircraft that are unable to determinetheir air-ground status automatically,the RTCA standards and TSOs allow theaircraft to continuously transmit the

airborne position message. However, thelength width code is a required messageelement in this rule, and is onlytransmitted in the surface positionmessage. Thus, to comply with the rule,the aircraft must automaticallydetermine its air-ground status andtransmit the surface position messagewhich includes the length width codewhen on the ground.

4. Indication of the Aircraft’s BarometricPressure Altitude

The NPRM proposed a broadcastmessage that would report the aircraft’s

barometric pressure altitude. Severalcommenters, including the ARC,GAMA, Rockwell-Collins, SandiaNational Laboratories (SANDIA), andUPS, identified an inconsistencyregarding the barometric altitudemessage element between the proposedrule’s preamble and regulatory text.

The FAA agrees that the NPRMpreamble was not completely clear andshould have better reflected theproposed regulatory text. The proposedregulatory text stated that the pressurealtitude reported for ADS–B Out andMode C/S transponder is derived fromthe same source for aircraft equippedwith both a transponder and ADS–BOut. The FAA confirms that the

barometric altitude reported from theaircraft’s transponder and ADS–B Outmust be derived from the same source.

In addition, the FAA is striking the January 1, 2020 compliance date fromproposed §91.217(b). If an operatorchooses to use ADS–B before January 1,


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43 EUROCAE MOPS for 1090 MHz AutomaticDependent Surveillance-Broadcast (ADS–B).

2020, the operator must meet theprovisions of that section.5. Indication of the Aircraft’s Velocity

The NPRM proposed a messageelement that would provide ATC withinformation about the aircraft’s velocityand direction. However, the NPRMpreamble mistakenly referred to velocityas airspeed. Several commenters,

including Airbus, the ARC, Rockwell-Collins, SANDIA, and UPS,recommended that the message elementreflect velocity instead of airspeed.Rockwell-Collins noted that velocitycould be derived from other sources,including an inertial navigation system.ACSS, United Airlines, and UPSrecommended that the FAA require thevelocity source for ADS–Btransmissions to be the most accuratevelocity source on the aircraft. The ARCrecommended that the issue of velocitysource be referred to RTCA.

This message element will provideATC with the aircraft’s velocity, as wellas a clearly stated direction anddescription of the rate at which anaircraft changes its position. Thevelocity must be transmitted with aNACV of less than 10 meters per second.Any velocity source that meets theserequirements will comply with this rule.The FAA referred the question onvelocity source to RTCA for furtherreview, as the ARC recommended.RTCA determined that the velocitysource must be the same source thatprovides the aircraft’s position, andincluded this requirement in DO–260Band DO–282B.6. Indication If Traffic Alert andCollision Avoidance System II orAirborne Collision Avoidance System IsInstalled and Operating in a Mode ThatMay Generate Resolution AdvisoryAlerts

The NPRM proposed requiring amessage element that would (1) identifyto ATC whether the aircraft is equippedwith TCAS II or ACAS and (2) identifywhether the equipment is operating ina mode that could generate resolutionadvisory alerts. Airbus asked for moreinformation on why this messageelement is required. EUROCONTROLcommented that this message elementshould be internationally harmonized

before the FAA adopts this requirement.UPS asked whether this message should

be indicated if the TCAS II is operatedin the traffic advisory mode. The ARCsought to retain this message element,

but asked the FAA to clarify itsintended use in the final rule.

The TCAS installed and operating ina mode that can generate a resolutionadvisory message will be used by the

FAA to monitor in-service performanceto address NAS inefficiencies and takeappropriate corrective actions. Thisinformation may also be used to supportfuture ADS–B In applications. Thismessage element was harmonized withthe international community in thedevelopment of DO–260B and ED–102A. 43

7. For Aircraft With an Operable TrafficAlert and Collision Avoidance System IIor Airborne Collision AvoidanceSystem, Indication If a ResolutionAdvisory Is in Progress

The NPRM proposed a messageelement to indicate that a resolutionadvisory is in progress. EUROCONTROLrecommended that the FAAinternationally harmonize this messageelement before adopting therequirement. Airbus noted that thiselement may be achieved with DO–260A.

Similar to the discussion in II.K.6.

above, the message that a TCASresolution advisory is in progress will be used by the FAA to monitor in-service performance to address NASinefficiencies and take appropriatecorrective actions. This information mayalso be used to support future ADS–B Inapplications. This message element washarmonized with the internationalcommunity in the development of DO–260B and ED–102A.

8. Indication of the Mode 3/ATransponder Code Specified by ATC(Requires Flightcrew Entry)

The NPRM proposed a messageelement to transmit the aircraft’sassigned Mode 3/A transponder code.

Several commenters, including ACSS,Boeing, SANDIA, and UPS, argued thatthis message element should not benecessary with ADS–B surveillance, andsuggested deleting the requirement.GAMA expressed concern that differentcodes in the Mode 3/A transponder andthe ADS–B could result in an indicationof a traffic conflict. GAMA specificallyrecommended a one code entry orrevising the automation to resolveconflicting information. Airbus and theARC supported this message element

requirement and the ARC requestedmore information on its intended use.The FAA has determined that the

same ATC-assigned Mode 3/A codemust be transmitted by both thetransponder and the ADS–B Outmessage. If the code transmitted byADS–B differs from the Mode 3/A codetransmitted by the transponder, it couldresult in duplicative codes or inaccurate

reporting of aircraft position. If theaircraft’s avionics are not capable of allowing a single point of entry for thetransponder and ADS–B Out Mode 3/Acode, the pilot must ensure thatconflicting codes are not transmitted toATC.

ATC uses the Mode 3/A code toidentify aircraft that are undersurveillance and possibly under ATC

direction. This identifier is necessary toissue directions to specific aircraft aboutnearby air traffic. The Mode 3/A codeand the International Civil AviationOrganization (ICAO) 24-bit address areduplicative for some functions. Thisduplication is necessary because manycurrent ATC automation systems are notyet capable of using the ICAO 24-bitaddress. Therefore, the FAA retains thismessage element in the rule.9. Indication of the Aircraft’s Call SignThat Is Submitted on the Flight Plan, orthe Aircraft’s Registration Number(Aircraft Call Sign Requires FlightcrewEntry)

The NPRM proposed a requirementfor this message element to indicateeither the aircraft’s call sign (assubmitted on its flight plan), or theaircraft’s registration number. Anindividual commenter disagreed withthe required broadcast message elementfor aircraft identity and noted that ituses unnecessary bandwidth.

This message element correlates flightplan information with the data that ATCviews on the radar display, andfacilitates ATC communication with theaircraft. This message element also willsupport certain ADS–B In applicationssuch as enhanced visual approach.

In the final rule, the regulatory text isamended to provide that an operatordoes not need to populate the call sign/aircraft registration field for a UATequipped aircraft if he or she has notfiled a flight plan, is not requesting ATCservices, and is using a UAT self-assigned temporary 24-bit address.Although the FAA does not prohibit theanonymity feature, operators using theanonymity feature will not be eligible toreceive ATC services, may not be ableto benefit from enhanced ADS–B search

and rescue capabilities, and may impactADS–B In situational awareness benefits.10. Indication If the Flightcrew HasIdentified an Emergency, RadioCommunication Failure, or UnlawfulInterference (Requires Flightcrew Entry)

The NPRM proposed this messageelement to alert ATC that an aircraft isexperiencing emergency conditions.Airbus asked the FAA to clarify whichemergency/priority codes are required.


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44 Mode A codes 7700, 7600, and 7500 currentlyare reserved for these emergencies. See Annex 10to the Convention on International Civil AviationAeronautical Telecommunications, Volume 4,Surveillance and Collision Avoidance Systems, 4thEdition, July 2007.

45 CDTI is a generic display that provides a flightcrew with traffic surveillance information aboutother aircraft, surface vehicles, and obstacles,including their identification, position, and othermessage set parameters. CDTI information wouldcommonly be displayed on a Multifunction Display(MFD).

The ARC recommended that the FAAexplain in the final rule the emergencystatus requirement and describe how itwill be used.

This message element alerts ATC thatthe aircraft is experiencing emergencyconditions and indicates the type of emergency. Both TSO–C154c and TSO–C166b identify six unique emergencycodes. All emergency codes may betransmitted. Under this rule, onlyemergency, radio communicationfailure, and unlawful interference arerequired. This information will alertATC to potential danger to the aircraftso it can take appropriate action.Message elements for minimum fuel,downed aircraft, and medicalemergency are not required by thisrule. 44 ADS–B equipment mayautomatically set these requiredemergency conditions based on theMode 3/A code.11. Indication of the Aircraft’s ‘‘ IDENT ’’

to ATC (Requires Flightcrew Entry)The NPRM proposed this message

element to help controllers quicklyidentify a specific aircraft. UnitedAirlines and UPS commented that they

believe controllers use the ‘‘ IDENT ’’

function to attain aircraft identificationinformation. They noted that futureidentification systems should includeaircraft information; therefore, they

believed this element is not necessary.FreeFlight commented that ‘‘ IDENT ’’

should be retained. The ARCrecommended that the FAA clarify howthe ‘‘ IDENT ’’ requirement will be used.

The ‘‘ IDENT ’’ function is usedregularly in current ATC operations tohelp controllers quickly identify aspecific aircraft. The ‘‘ IDENT ’’ featurealso allows ATC to quickly identifyaircraft that have entered incorrect flightidentification or Mode 3/A codes. TheFAA is adopting this message elementin this rule.12. Indication of the Emitter Category

The NPRM proposed requiring amessage element for an aircraft’s emittercategory.

EUROCONTROL questioned the business case behind this requirement.

UPS asked that the FAA better definethe emitter categorizations in the finalrule.

This message element is necessary forATC separation services and waketurbulence separation requirements.TSO–C166b and TSO–C154c provide a

list and description of the differentemitter categories. Emitter category isset during installation of the ADS–Bavionics in the aircraft and will notchange over time.

13. Indication Whether an ADS–B InCapability Is Installed

The NPRM proposed this messageelement to indicate to ATC whether a

cockpit display of traffic information(CDTI) 45 is installed and operational.Several commenters, including Boeing,EUROCONTROL, and SANDIA,commented that this message elementwas poorly defined, difficult andexpensive to implement, and of littlevalue to ADS–B In applications andATC surveillance. UPS asked whether amessage is required when a CDTI isinstalled but not operating. The ARCrecommended that the FAA clarify theuse of this data element.

RTCA updated the definition of thismessage element in DO–260B and DO–

282B. The FAA adopted these updatesin TSO–C166b and TSO–C154c. Thismessage element now indicates whichaircraft are capable of receiving ADS–BIn services and therefore require TIS–Band ADS–R transmissions from theground. Under the new definition, thismessage element now indicates whetheran ADS–B In capability is installed inthe aircraft, but does not require a reportof operational status.

14. Indication of the Aircraft’sGeometric Altitude

The NPRM proposed a messageelement indicating the aircraft’sgeometric altitude.Several commenters, includingAirbus, Boeing, Dassault, the EuropeanBusiness Aviation Association (EBAA),EUROCONTROL, Honeywell, andRockwell-Collins, commented on theproposed requirement. Most of thecommenters questioned this messageelement and stated that neither ATCsurveillance nor ADS–B In requiregeometric altitude. Dassault, EBAA,EUROCONTROL, and Honeywellsupported this message element. TheARC recommended that the FAA justifythe need for this message element.

Geometric altitude is the height of theaircraft above the World GeodeticSystem 84 ellipsoid, which is ascientific approximation of the earth’ssurface. This message element will beused within the ADS–B ground system

to confirm accuracy and identifydiscrepancies between geometricaltitude and barometric altitude.Additionally, the FAA will integratethis comparison function into acontinuing airworthiness monitoringfunction.

L. Ability To Turn Off ADS–B Out Transmissions

The NPRM proposed requiring a pilotto turn off ADS–B equipment if directed by ATC, for example, if the ADS–B unitwas broadcasting erroneousinformation.

The ARC, Boeing, United Airlines,and UPS recommended eliminating therequirement to turn off ADS–B Outtransmissions. A few commenters,including British Airways, wereconcerned that being able to turn off ADS–B Out, while keeping thetransponder on, could requireadditional design changes and increasecosts because most existing equipment

is not capable of operating in thismanner. Boeing stated that eliminatingerroneous ADS–B transmissions could

be accomplished by turning thetransponder off or having a capabilitywithin the ground system to allow thecontroller to manually remove selectedtargets. Rockwell-Collins recommendedthat the FAA require the ADS–Bequipment to detect failures and disableADS–B Out transmissions of erroneousdata.

The FAA modified the groundautomation system to be able to excludeincorrect ADS–B data. With thisenhancement to the automation, theaircraft does not need to have acapability for a pilot to disable ADS–Btransmissions. Therefore, the final ruledoes not require the pilot to be able toturn off ADS–B Out transmissions.

M. Existing Equipment Requirements

1. Transponder RequirementThe NPRM specified that the proposal

for ADS–B equipage would not alterexisting transponder regulations.

Several organizations and individuals,including AOPA, opposed adding ADS–B Out performance requirementswithout removing the transponderrequirement. ATA and Boeing requestedthat the FAA make a commitment toremove transponders. Severalorganizations and individuals furthercommented that the FAA should pursuean ADS–B based collision-avoidancesystem and reconsider the backupstrategy, which is based on secondarysurveillance systems. ALPA supportedthe FAA’s plan to retain transponders.

The ARC made multiplerecommendations associated with


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46 An ELT is an electronic battery-operatedtransmitter developed as a means of locatingdowned aircraft.

47 The ARC recommended DO–260A Change 3,which is DO–260B.

transponder removal: (1) The ADS–Bimplementation strategy should includethe removal of transponders from low-altitude aircraft without an ACAS; (2)the FAA should commit to a strategy forachieving transponder removal fromlow-altitude domestic aircraft; and (3)the FAA should study whether ACAScan be modified to use ADS–B as theprimary surveillance data for collisionavoidance, as well as what ACASupgrades are required to supportNextGen.

Removing the transponderrequirement would involve substantialchanges to the ADS–B backup strategyand TCAS II/ACAS, which are outsidethe scope of this rulemaking.Transponders will still be requiredwhen the backup surveillance strategyusing SSR is necessary and to interactwith TCAS- and ACAS-equippedaircraft. Separate from this rulemaking,the FAA may consider (in coordinationwith the appropriate surveillance and

NextGen planning organizations),whether transponders could eventually be removed and, if so, what steps arenecessary to accomplish this.

2. Emergency Locator TransmitterRequirement

The NPRM did not propose anychanges to the emergency locatortransmitter (ELT) 46 requirements.

Several commenters, including ATAand the National Business AviationAssociation (NBAA), argued that ADS–B should be used instead of an ELT, andthat ELT requirements could beincluded in this rule. AOPA alsorecommended a long-term strategy toinclude ELT removal, and stated thatADS–B could enhance current search-and-rescue procedures to increase thenumber of successful rescues.

The ARC recommended that the FAAexplore whether an ADS–B trackingservice also could be used for searchand rescue to aid in crash locating. TheARC also recommended that the FAAconduct a study considering an ADS–B-

based search-and-rescue solution thatwould enable removal of 121.5 MHzELTs for certain domestic operations.

The FAA has determined that the

ADS–B system currently cannot replacethe ELT function. The ADS–B system isnot required to be crashworthy and,thus, may not be operable or able totransmit following an aircraft accident.Additionally, current search-and-rescuetechnology is not compatible with ADS–B operations because ELTs broadcast on121.5 or 406 MHz (not 1090 or 978

MHz). The FAA recognizes the value of a ground application that could allowfor timely and accurate flight tracking of downed aircraft and is evaluating thiscapability separate from thisrulemaking.

The FAA considered the ARCrecommendation to evaluate thefeasibility of replacing the ELT with theADS–B system. However, the FAA hasdetermined that ADS–B is not a feasiblereplacement for the ELT, as discussedabove; therefore, the FAA does not planto undertake such a study at this time.

N. Program Implementation

1. TimelineThe FAA proposed that all aircraft

operating in the airspace areas specifiedin the rule meet the performancerequirements by January 1, 2020.

The majority of commentersrecommended various options for theimplementation of ADS–B, includingthe discontinuation of secondary and/orprimary radar systems once ADS–B isoperational NAS-wide. Somecommenters, including AIA and AOPA,requested that the FAA provide certain

basic levels of ADS–B service for severalyears before the ADS–B compliancedate.

Several commenters, including ALPAand the National Transportation SafetyBoard (NTSB), suggested that thecompliance date or service provision of ADS–B occur sooner than 2020, toobtain benefits more quickly. UnitedAirlines recommended a 2015compliance date for operations above FL

240. The Cargo Airline Association(CAA) recommended lower performancerequirements for a 2015 compliancedate. Several commenters, including theAircraft Electronics Association, FedEx,and the National Air CarriersAssociation, suggested extending oradding flexibility to the 2020compliance date.

Numerous commenters, includingATA, Boeing, IATA, and Rockwell-Collins, suggested a two-phasedimplementation strategy. The first phasewould use existing equipment, avionicsstandards, and capabilities, whichwould allow industry and the FAA todemonstrate, validate, and evaluateADS–B applications. After operationalexperience in the first phase wassufficient to generate the appropriatestandards, the second phase wouldestablish a mandate for ADS–B Outperformance standards. Somecommenters suggested that the secondphase be a combined ADS–B In andADS–B Out rule.

The ARC endorsed the proposed 2020compliance date, but recommended that

the FAA allow operators to use existingequipage to accrue early benefits.Specifically, the ARC recommendedthat the FAA: (1) Take advantage of existing 1090 MHz ES-equipped aircraftand allow their operation in the Gulf of Mexico for non-radar airspace and (2)transition to a fully functional ADS–BOut capability enabled by DO–260B, 47 to allow access to the additionalapplications and services for ADS–B In.The ARC also recommended that theFAA adopt the European AviationSafety Agency (EASA) AcceptableMeans of Compliance 20–24 (permittingthe use of early DO–260 avionics forseparation) in non-radar airspace, withappropriate measures to ensure ADS–Bintegrity.

After reviewing all the comments, theFAA finds that a 2020 compliance dateremains appropriate because NAS usersneed time to equip to the requirementsof the rule. Most air carriers can useregularly scheduled maintenance toinstall or upgrade their equipment. TheFAA also expects that this timeframewill provide sufficient operationalexperience to make ADS–B the primarysource for surveillance in 2020.

FIS–B and TIS–B services are alreadyavailable in several areas of the countryfor ADS–B In-equipped aircraft and willcontinue as an integral part of theimplementation of the ADS–B groundinfrastructure. NAS-wide groundinfrastructure implementation isscheduled to be complete in 2013,which would provide operators with atleast 7 years of operational experiencewith these services before the ADS–Bcompliance date of 2020.The FAA examined whether it isoperationally feasible and economically

beneficial to use DO–260 avionics inradar and non-radar airspace before2020. From an operational perspective,the FAA found that the existing DO–260equipment does not meet thesurveillance needs for ATC in theUnited States for various reasons: (1)DO–260 avionics do not independentlyreport the accuracy and integritymetrics; (2) DO–260 avionics allow theintegrity metric to be populated withaccuracy information during integrity

outages, which is unacceptable foraircraft separation services; (3) DO–260avionics do not include a messageelement for Mode 3/A code, which isnecessary for aircraft surveillance; and(4) the majority of existing DO–260installations were accomplished on anoninterference basis under thetransponder approval guidelines. (Thiscertification verifies that the equipment


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48 URET is an air traffic control tool that assistscontrollers with timely detection and resolution of predicted air traffic problems.

49 A copy of the DO–260 Business Case Analysisis available from the Web site http:// www.regulations.gov . The docket number for thisrulemaking is FAA–2007–29305.

50 The analysis concluded that it was not cost- beneficial to use DO–260 avionics in the Gulf of Mexico prior to 2020.

51 A copy of the Honeywell Technology SolutionsInc. DO–260 study is available from the Web sitehttp://www.regulations.gov . The docket number forthis rulemaking is FAA–2007–29305.

52 The DO–260 Business Case Analysis assumedthe cost of $15,000 to upgrade an aircraft equippedwith DO–260 only. The cost does not include allcosts to meet the rule. The cost was used for theDO–260 Business Case Analysis and not used in theRegulatory Impact Analysis.

53 The planned ADS–B service coverage isexplained in greater detail at http://www.adsb.gov/.

is safe onboard the aircraft, but does notissue any approval that would permit itsuse for ADS–B operations.)

Therefore, the FAA concluded thatwithout upgrades to the equipment, theuse of DO–260 avionics will not meetthe surveillance needs in the NAS.Furthermore, without appropriateintegrity monitoring, DO–260 avionicscannot be used for separation of aircraft.Its utility would be limited topotentially reducing separation in non-radar areas, or increasing efficiency inradar airspace through more timelyupdates of information.

Further analysis addressed whetherexisting DO–260 avionics could be

beneficial to provide separation servicesin the Gulf of Mexico, or to provideefficiency benefits through improvedperformance of User Request EvaluationTool (URET) 48 and Traffic ManagementAdvisor (TMA).

To use DO–260 avionics in the Gulf of Mexico, the FAA estimated it would

incur approximately $4 million in coststo upgrade the automation; would needto provide additional ground stationsand receiver autonomous integritymonitoring (RAIM) predictions; wouldneed to develop procedures; and wouldneed to address aircraft certificationissues. 49 Comparatively, the FAAconcluded that benefits from this actionwould only recover approximately 70percent of the costs.

The costs associated with usingexisting DO–260 avionics relative toimproved performance of URET andTMA were estimated at $31 million andthe estimated benefit in performancewas $72 million. While this analysisindicated that the benefits of improvedURET and TMA performance outweighthe costs of accommodating DO–260equipped aircraft, 50 the FAA found thatit raised some policy concerns.

First, the FAA does not expect to havethe full NAS-wide ADS–B infrastructurecompleted for this effort until 2013. Asthe ADS–B rule would go into effect in2020, any benefits accrued through theuse of DO–260 avionics would only beavailable for approximately 7 years.Operators would be required to make asecond investment in avionics tocomply with the rule in 2020.

Second, a collection of broadcastsamples indicated that there is a wide

variety of equipage among current DO–260 users. Although approximately7,500 aircraft in the United Statestransmit some ADS–B data that wouldconform to DO–260, only about 1,500aircraft transmit enough data to beuseful for 5 NM separation in the Gulf of Mexico and input into ATC decisionsupport tools (URET and TMA). 51 ManyDO–260 operators would require someupgrade costs to bring their existingsystems into compliance with a unifiedstandard; these would be in addition tothe costs incurred for taking aircraft outof service for certification. Although theuser costs were not thoroughly assessed

by the ARC, the FAA estimated the costsat $15,000 per aircraft. 52

Given the above, the FAA could notjustify the proliferation of avionics forthe short-term that would not becompliant with the final rule in 2020.Therefore, the agency concluded thatthe public interest was not best served

by using DO–260 avionics for ADS–Bapplications in radar and non-radarairspace before 2020.2. Financial and Operational Incentives

Numerous commenters, includingAIA, the ARC, and NBAA,recommended a variety of financial andoperational incentives to make ADS–Bmore cost-beneficial for the end user.Some commenters specificallyrecommended that the FAA offeradditional incentives for operators whoadopt early. NBAA recommendedaccelerated operational benefits toencourage early installation of ADS–Bequipment. Several commenters stated

that without operational incentives,aircraft operators with legacy equipmentwill delay upgrades until the mandatedcompliance date.

AOPA and the Helicopter AssociationInternational (HAI) recommended several operational improvements and safety enhancements for ADS–B,including: (1) Flight following and radarservices at lower altitudes, (2) terminalATC services at GA airports,(3) automatic instrument flight planclosure, (4) instrument flight rules (IFR)low altitude direct routing, (5) enhancedflight service information, and(6) improved real time weather. HAIalso recommended that the FAA installground stations near hospitals andtrauma centers to maximize benefits for

the emergency medical servicescommunity and encourage ADS–Bequipage.

ATA, CAA, the National AirTransportation Association, NBAA, andUPS recommended specific operationalincentives for early equipage, including:(1) Implementing ADS–B in under-usedareas of the NAS, (2) providingpreferential access to congestedairspace, (3) deploying the necessaryADS–B infrastructure for traffic crossingthe Gulf of Mexico, and (4) providingservices for on-demand operators atsmall community airports.

Some commenters, including AOPA,HAI, and CAA, recommended financialincentives or tax credits for ADS–Bequipage.

The following activities are scheduled to be complete by 2013:

• Ground infrastructure coverageneeded for the mandated airspace, 53

• ADS–B interface to automationsystems,

• Guidelines for equipmentcertification,• Operations Specifications approval,• Approval to use ADS–B to meet

established separation standards,• ATC operational procedures for

non-radar airspace that has ADS–Bcoverage, and

• FAA controller training andprocedures.

The ADS–B program is currentlyfunded and designed to provide servicesin parts of Alaska, the Gulf of Mexico,and areas in the NAS where radarcoverage currently exists. Additionally,actual ADS–B coverage may exceed thedefined radar coverage at loweraltitudes in some areas. The FAA cannotassess, however, the extent of thiscoverage or its potential use for theADS–B service until the ADS–Bimplementation is complete in 2013.

The FAA acknowledges that the ADS–B system could be improved byexpanding the surveillance coverage of ADS–B to non-radar airspace. Theimproved accuracy and update rateafforded by ADS–B provides the abilityto improve future NAS operations. Asthe number of projected flightoperations continues to increase,

efficiency improvements to the NAS arecritical to addressing new demands.Therefore, the FAA will continue toexplore opportunities to use the ADS–B infrastructure to provide additionalcoverage in non-radar areas. The FAAalso notes that ADS–B implementationwill not affect flight following servicesin effect today.


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The FAA is actively pursuingagreements with airlines, avionicsmanufacturers, airports, and other NASusers to encourage early equipage of ADS–B. These agreements incorporate avariety of items, including: (1) Thepossibility of developing preferredroutes and cost sharing for avionics intesting new applications, and (2) earlyequipage and experience with advancedADS–B applications that are notavailable to non-equipped aircraft.

The FAA currently has severalagreements with airlines and stateentities specifying that the FAA mayenable benefits in exchange for earlyADS–B equipage. Additionally, theFAA, HAI, and oil platform owners havean agreement for the Gulf of Mexico bywhich the FAA is providingcommunication, navigation, andsurveillance for ADS–B-equippedhelicopter operators.

The FAA and UPS have an agreementfor testing and developing merging and

spacing, CDTI/Multi Function DisplayAssisted Visual Separation (CAVS), andsurface situational awarenessapplications in an environment thatprovides measurable benefits.Additionally, the FAA is working withHoneywell and ACSS to accelerateASSA, FAROA, and surface indicationand alerting applications.

The FAA is working with US Airwaysto develop a work plan forimplementing ADS–B/NextGentechnologies and procedures in parts of the East Coast as a prelude to nationalimplementation. In addition, the FAA

has an agreement with United Airlinesto expedite oceanic in-trail proceduresdevelopment. The FAA is also workingwith NetJets on several NextGeninitiatives for performance-basednavigation, communication, andsurveillance applications.

The FAA has established an ADS–Bcompatible Wide Area Multilaterationsystem in the mountainous areas of Colorado pursuant to an agreement withthe Colorado Department of Transportation. The FAA continues toexamine different areas of the country todetermine opportunities for surveillanceservice expansion and is continuing towork with various state aviation offices.

In addition, the FAA continues toexamine opportunities to provide ADS–B services in areas that would benefitfrom increased surveillance. The FAAdoes not currently have a list of airportsthat are targets for ADS–B expansion.However, the FAA has started toidentify areas that would benefit mostfrom ADS–B services. The FAAencourages cities, states, airports, andprivate interests (such as hospitals and

trauma centers) to help determinesurveillance needs and opportunities.

ADS–B can provide surveillance atlower altitudes than radar. Moreover,ADS–B infrastructure is more easilydeployed than most radar in remote andhard-to-reach areas. The flexibilityassociated with implementing ADS–Bcan facilitate service by helicopters tocertain communities. Deployment of

ADS–B systems on medical, police, ortourist helicopters could provide a levelof asset tracking and search-and-rescuecapability that would be difficult toreplicate with existing surveillancesystems. The FAA has alreadydeveloped agreements with HAI tosupport operations in the Gulf of Mexico. The FAA is open toimplementing similar agreements asopportunities for ADS–B serviceexpansion present themselves.

While this rule does not mandateADS–B equipage in all airspaceclassifications, the FAA is analyzingwhether ADS–B services can beexpanded to provide improved safetyand capacity enhancements for lowaltitude flight operations and airportsunderlying non-mandated airspace. TheFAA will work with users to identifynew candidate airports for theseservices. This activity will continuethroughout the initial implementationperiod and post 2013 when thenationwide ADS–B infrastructure isexpected to be available NAS-wide.

The extent to which ADS–B cancontribute to operations in special useairspace is still being studied; however,the FAA is committed to examining anyproposals for the use of ADS–B outsideof the scope of implementationdescribed in this rule.3. Decommissioning Traffic InformationService–Broadcast (TIS–B)

In the NPRM preamble, the FAAnoted that once all aircraft are equippedwith ADS–B Out, ADS–R will providethe complete traffic picture and the FAAwill decommission TIS–B.

A few commenters, including theDOD, questioned the assumption that allaircraft would be equipped for ADS–BOut. Rockwell-Collins recommendedretaining TIS–B after the ADS–Bmandate takes effect, because itprovides a critical support for ADS–Bairborne applications.

The original purpose of TIS–B was toprovide proximate traffic information toADS–B In-equipped aircraft abouttargets that were not equipped withADS–B. When this rule takes effect in2020 aircraft operating in the airspacesubject to this rule must be equippedwith ADS–B, thus theoreticallyeliminating the need for the TIS–B

service. However, the FAA realizes thatTIS–B may still have value after 2020 asa backup traffic service for ADS–B Inaircraft during GNSS outages or whenan individual target’s ADS–B system isinoperative. Thus, the FAA, outside of this rulemaking effort, will evaluate the

benefits of continuing TIS–B past the2020 rule compliance date.O. Safety

Several commenters, includingAOPA, the ARC, and Boeing, suggestedthat the FAA expand the ADS–B servicevolume and ensure that TIS–B, FIS–B,and ADS–R are included in the ADS–Bexpanded coverage area.

Some commenters believed thatreducing primary radars would reducesafety. These commenters noted thatprimary radar is important to trackaircraft without ADS–B. They alsorecommended that the FAA continuerequiring transport category aircraft toequip with Mode S transponders andTCAS II as an independent collisionavoidance system. Some commentersargued that the complexity of theADS–B system poses a collision risk.

Other commenters noted that ADS–BIn cockpit displays can be confusingand distracting, which may cause a pilotto lose situational awareness. Theyadded that the FAA should evaluate theCDTI to understand the additionalmonitoring responsibility and workloadplaced on the flightcrew. Oneindividual contended that ADS–B willincrease a pilot’s dependence on cockpitequipment and reduce the pilot’stendency to look outside the aircraft.

Another individual commenter askedfor data to prove that ADS–B will not besusceptible to own-ship ghosting ortarget duplication. ( ‘‘ Own-ship ghosting ’’

is a term that is used to describe a trafficdisplay showing one’s own aircraft as anactual target. Ensuring targets that aretransmitting ADS–B are not alsotransmitted as TIS–B targets helpsreduce the chances of seeing one’s ownaircraft as a target on the display.)

The final rule does not eliminate therequirement for transponders, TCAS, orprimary radars. The FAA notes that anyaircraft required to have TCAS II orACAS, or that voluntarily has TCAS IIor ACAS installed, must also beequipped with a Mode S transponder.This generally includes all aircraftoperated under 14 CFR parts 121, 125,and 129, and certain aircraft operatedunder 14 CFR part 135.

Mode S transponders transmit bothaircraft altitude and aircraftidentification information. Both ModeA/C transponders and Mode Stransponders require interrogation toprovide information. ADS–B In Conflict


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54 Surveillance and Broadcast Services SystemsEngineering Separation Standards Working Group,Final Report on Operational Evaluation of 5 NMADS–B to Radar Separation Services in Alaska,November 30, 2006.

Detection does not replace the functionsof TCAS II or ACAS; however, futureversions of hybrid surveillance systemsmay use passive ADS–B messages toreduce unnecessary interrogations and,thus, reduce 1090 MHz spectrumcongestion.

As stated in the NPRM, the FAA ismaintaining its current network of primary radars. However, the FAA

expects to reduce a large percentage of its secondary radars as a result of thisrule. Both primary surveillance radarand SSR will continue to be used forsurveillance during the transition periodof ADS–B avionics equipage.

The benefits of certain ADS–B Inapplications cannot be fully realized inareas where there is no ADS–Bcoverage; however, the lack of ADS–Bsurveillance or ADS–R does not presenta safety risk. When an aircraft is outsideof the ADS–B coverage area, the ADS–R/TIS–B system will inform the pilotthat the traffic picture is not complete.In all areas, regardless of ADS–Bcoverage, pilots will use the sameprocedures they have today to maintainsafe separation of aircraft. TIS–B andFIS–B services are advisory and cannot

be used to maneuver an aircraft withoutATC clearance. The FAA willinvestigate ADS–B service expansion aspart of the ADS–B NAS-wideimplementation.

With regard to the comment regardingown-ship ghosting, the ADS–B systemminimizes the chance of targetduplication because it will not transmitTIS–B data on a target that is

broadcasting ADS–B. This is becauseADS–R is designed to relay informationabout aircraft transmitting on a different

broadcast link, and TIS–B is designed torelay information only about aircraft not

broadcasting ADS–B messages.This rulemaking only mandates ADS–

B Out, which does not involve anyrequirements for a cockpit display.Before any mandate of ADS–B In, theFAA will conduct extensive safetyanalysis and training. The current ADS–B Out rule does not eliminate or reducethe requirement under § 91.113 forpilots to see and avoid other aircraft.P. Efficiency

In the NPRM preamble, the FAAstated that ADS–B will enhance ATCsurveillance, which will increaseairspace efficiency and capacity to meetthe predicted demand for ATC services.

Several commenters, including theAirports Council International—NorthAmerica (ACI–NA), Boeing, and FedEx,commented on the anticipatedefficiency improvements stated in theNPRM. Some commenters contendedthat the proposed rule did not prove

that a decrease in en route separation of aircraft will decrease delays or increaseairspace capacity. Two commentersargued that the FAA has notdemonstrated that system choke pointscan handle the increased capacity if enroute separation is reduced.

Other commenters, including theNational Air Traffic Controllers

Association, argued that reducingseparation will not mitigate commercialtraffic delays caused by an inadequatenumber of runways, weather, hub-and-spoke operations, or airline schedulingpractices. Era Corporationrecommended that the FAA improve theinfrastructure at small airports to relievecongestion. Boeing stated that ADS–Balone will not lead to the advancesrequired by NextGen.

The FAA has consistently stated thatADS–B will not produce a completeNextGen air traffic managementsolution, but rather will set the initialsteps to achieving a NextGen solution.The airport infrastructure is a crucialcomponent of the NAS. Efficiency andcapacity of the NAS can be positivelyaffected by improving the efficiency of individual flights and improving thequality of input to air traffic controllers.ADS–B can help maximize the use of existing airport infrastructure. Theability to transmit ADS–B Out messagescan increase the efficiency of the NASin radar airspace by providing accurateupdates at a faster rate than manyexisting surveillance systems. This

increased update rate permits ATC tomerge and sequence aircraft moreeffectively into existing airport chokepoints, which should mitigate, ratherthan increase, congestion and delay.This rule’s regulatory evaluation doesnot include any benefits that aredependent on, or attributable to, otherNextGen systems outside the scope of this rulemaking.

The FAA expects that ADS–B Outwill enable the establishment of moredirect routes outside airspace subject tothis rule, which would use less fuel,emit less carbon dioxide and nitrogenoxide, and increase NAS efficiency. TheFAA is currently developing specificADS–B routes for certain areas that havethe potential for significant benefits(airspace off the shore of the east coastand over the Gulf of Mexico). The FAAexpects that other opportunities forroutes enabled by ADS–B will emerge asthe ground infrastructure isimplemented NAS-wide.

1. Improved Position ReportingAccording to operational

evaluations, 54 ADS–B providesimproved accuracy over radar in mostair traffic scenarios. While someterminal radars can provide increasedaccuracy the closer the aircraft is to thereceiver, ADS–B provides consistentposition accuracy regardless of theaircraft’s range from a receiver. ADS–Balso provides more timely informationupdates than conventional radar. Unlikeradar, the accuracy and integrity of ADS–B Out is uniform and consistentthroughout the service areas. Therefore,ATC’s ability to accurately identify andlocate aircraft that are further away fromthe air traffic control facilities will be

better than radar.ADS–B does not scan an environment

in the same way as radar; therefore,ADS–B does not provide unnecessaryreturns based on weather or otherobstructions, which can impede theeffectiveness of primary radars.

ADS–B provides consistent,frequently updated position reportingand additional aircraft information forATC decision-support tools, whichincreases ATC confidence in aircraftposition. This will allow ATC to applyexisting separation standards moreexactly and without the need for ATC tocorrect for possible radar inaccuracies.The regulatory evaluation providesmore discussion on the benefits of improved surveillance information.

2. Optimized Profile Descents (OPDs)The FAA plans to use the information

broadcast by ADS–B to better sequenceaircraft approaching the terminal areawith the development of a Merging andSpacing application. This ground-basedsystem sends precise suggested speedinstructions to en route aircraft. Theseexact-speed instructions should allowaircraft to arrive at extended terminalarea merge points at times that are muchmore precise than currently feasible.

As part of the Merging and Spacingapplication, the FAA is developing botha ground tool and aircraft requirementsthat can be used to optimize aircraftspacing. In addition to other airspaceefficiencies, this tool will enable a fuel-saving procedure called OptimizedProfile Descent (OPD), previouslyreferred to as Continuous DescentArrivals (CDAs).

OPDs are a type of terminal arrivalprocedure, specifically designed to keepan aircraft at, or near idle power during


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55 The final approach fix identifies the beginningof the final approach segment, and is the fix fromwhich the final instrument flight rule (IFR)approach to an airport is executed.

56 These applications include Enhanced visualacquisition, conflict detection, and enhanced visualapproach.

the entire arrival until the finalapproach fix. 55 These proceduresincrease flight efficiencies whilereducing noise, fuel consumption, andemissions. OPDs eliminate step-downaltitudes and the associated inefficientpower adjustments. OPDs depend onminimal aircraft vectoring to maintainthe arrival pattern. Therefore, aircraftmust be accurately metered with ADS–B-enabled spacing and sequencing toolsprior to and during descent andapproach.

Below a certain level of demand,controllers can authorize OPDs usingcurrent onboard equipment andprocedures. As the terminal demandincreases, it becomes progressively moredifficult for controllers to allow OPDs

because of interference with other trafficflows in the airspace. As demandapproaches capacity, the tradeoff

between total airport throughput (anddelays) and individual flight profileefficiency (that is, OPDs) would most

likely prohibit OPDs for very high trafficdensity situations. This situation will beaggravated over time as air trafficresumes growth and terminal airspaceconstraints increase.

Many airports start to exhibitsignificant delays when demand reachesapproximately 70 percent of capacity.The proposed FAA spacing tool, usingmore accurate ADS–B positioninformation, would enable OPDs inmedium-density terminal airspace whenthe demand approaches the point wheredelays would be encountered. The FAA

believes that ADS–B Out can expanduse of OPDs into medium levels of traffic density (40 percent to 70percent), which may not be possiblewithout ADS–B Out. AccomplishingOPDs at this level of traffic densitywould have important environmentaland energy benefits with no increase incongestion or delay.

3. Reduced Aircraft SeparationIn non-radar airspace, ADS–B Out

allows ATC to apply radar-likeseparation standards in areas whereATC currently applies non-radar,procedural separation. In some cases,routes laterally separated without radar

by as much as 90 NM are now separatedwith ADS–B at only 20 NM.Longitudinal separation of typically 10minutes (80 NM) can be reduced to 5NM.

Boeing commented that the accuracyand integrity values proposed in theNPRM will not support reduced en

route separation standards. ADS–Bposition accuracy supports currentsurveillance standards. Experience withthe mature system may allow reductionsat a future time. The FAA plans toexpand 3 NM separation to locations inthe NAS that currently only permit 5NM separation. Currently, the FAA ismodeling several scenarios to determineif ADS–B can support 3 NM en routeseparation based on a target level of safety. The FAA will not move forwardwith reduced separation until all safetyand operational analyses have beencompleted and ADS–B has beencertified to perform this service.4. Expanded Surveillance Coverage

In the future, there may also be anopportunity for ATC to use ADS–B Outdata for surveillance in areas of the NAS

below the floor or outside the lateralcoverage of existing radar surveillance.The FAA does not yet know where inthe NAS this extra coverage might beavailable. This information will likelynot be available until ADS–Bsurveillance has already beenimplemented in a service area. As theFAA identifies areas with additionalcoverage, the FAA will investigate howthis additional coverage could be used.Q. ADS–B In

Many commenters, including ACSS,ALPA, CAA, Lockheed Martin, theNTSB, and UPS, commented that themajority of the ADS–B benefits will bederived from ADS–B In. Numerouscommenters asserted that ADS–B Outalone would not be cost-beneficial or

provide them with any added benefitscompared to their operations today.Some commenters noted that ADS–B In,however, would provide necessaryservices to the cockpit. Many of thesecommenters asserted that ADS–B Inshould be mandated as well. However,AOPA specifically recommended thatADS–B In be voluntary because it iscost-prohibitive for most GA owners.British Airways also questioned the

business case for ADS–B In.Many commenters, including the

DOD, ACI–NA, and AIA, pointed outthat the capabilities and functions of ADS–B Out alone will not provide thefull range of benefits available fromADS–B. To improve the overall system,they recommended developingstandards for ADS–B Out in unison withstandards for ADS–B In. GAMA andIATA recommended that the FAA workto define the requirements for ADS–B Into encourage ADS–B equipage. ATAspecifically asked the FAA to defineADS–B In standards by 2010. IATAnoted that many operators will delayupgrades until there is a single, defined

ADS–B package with avionics andprocedures to support NextGen and theSingle European Sky Air TrafficManagement (ATM) Research Program.

The ARC recommended that the FAA,in partnership with industry, define astrategy for ADS–B In by 2012 andensure that the strategy is compatiblewith ADS–B Out avionics. The ARC alsorecommended that the FAA describehow to proceed with ADS–B In beyondthe voluntary equipage conceptdiscussed in the NPRM.

A few commenters, including NBAA,praised the benefits of ADS–B andrecommended that the FAA resolveADS–B In display requirements,including human factors. The NTSBstated that ADS–B would significantlyimprove situational awareness forpilots, especially during groundoperations. GAMA recommended thatthe FAA not limit display options in thefinal rule.

The FAA fully recognizes that

ADS–B In and other future air-to-airapplications are functions that couldprovide substantial benefits to aircraftoperators and the NAS. Whileadditional benefits can be accrued usingADS–B In functions, requirements foran ADS–B In system are not sufficientlydefined to implement them at this time.

ADS–B Out is necessary to establishan air transportation infrastructure thatis consistent with the NextGen plan andwill change the way the NAS operates.Further, the economic evaluation of theADS–B Out proposal found the systemto be cost-beneficial if ADS–B Outavionics costs are at the low end of theestimated cost range and if the benefitsare at the high end of the estimated

benefits range.Given the value of ADS–B In services

to individual operators and the benefitsto future NAS operations, therequirements adopted for ADS–B Outalso support certain ADS–B Inapplications. 56 The FAA has modifiedseveral aspects of the proposed rule tominimize the cost impact to operators of the requirements driven by ADS–B In.The requirements in this final rule alsoestablish a stable infrastructure forcurrent and future applications of

ADS–B In.The FAA concurs with the ARC’srecommendation to define a strategy forADS–B In equipage by 2012 and isworking with industry to develop astrategy for future ADS–B Inapplications. By 2012, the requirementsand benefits of ADS–B In applicationsshould be well enough defined for the


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57 ASAS provides the platform for the processingand display of ADS–B In applications.

FAA to specify a set of performancerequirements that would be tied to awell-defined bundle of applications.

Furthermore, RTCA has completedthe DO–317, Minimum OperationalPerformance Standards (MOPS) forAircraft Surveillance ApplicationsSystem (ASAS), 57 and the FAA iscurrently developing a TSO to utilize

this RTCA standard.R. ADS–B in Applications

Multiple commenters, includingSANDIA, asked for more informationabout potential ADS–B In applications.This information is provided below.

1. Surface Situational Awareness WithIndications and Alerting

This application is being designed toprovide information regarding potentialtraffic conflicts on or near the airportsurface to the flightcrew. The ADS–B Incockpit display would indicate therelevant runway occupancy status.Depending on the severity of theconflict, the system would alert theflight crew with visual and/or audiblealerts.

2. In-Trail Procedures

This application is being designed tofacilitate aircraft conducting oceanic in-trail flight level changes using a reducedseparation standard. This applicationshould improve the use of oceanicairspace, increase efficiency, reduce fuelconsumption, and increase safety by

helping flightcrews avoid turbulentflight levels. With this application, ATCwill continue to provide proceduralnon-radar separation services. However,the FAA is exploring whethercontrollers would be able to allow flightlevel changes where aircraft areseparated by only 15 NM during climbor descent, instead of 100 NM in usetoday.

3. Interval Management

This application is intended toimprove current merging and spacingcapabilities to ensure more consistentaircraft spacing, and potentially increaseairspace capacity. With this application,controllers would issue a different set of instructions to pilots, for example, tomaintain a given time or distance fromthe preceding aircraft. The flight crewswill then use ADS–B In information toadjust their airspeeds or flight paths tomaintain the instructed separation.

4. Airport Surface SituationalAwareness and Final Approach RunwayOccupancy Awareness

ASSA and FAROA increasesituational awareness of potentialairport ground conflicts at several of thenation’s busiest airports. However, thereduced NAC P requirement in this rule,while sufficient for ADS–B Out, is not

sufficient for all aircraft to use in ASSAand FAROA.

S. International Harmonization

Several commenters stated that theADS–B program technical standards andrequirements in the NPRM may beexclusive of, and not harmonized with,ICAO and international efforts underway in Europe, Australia, and Canada.Several individual commenters andAOPA questioned the interoperability of UAT in international airspace,including Canada and Mexico. Theyalso questioned the applicability of UAT

through ICAO Standards andRecommended Practices (SARPs). TheARC recommended that the FAAadvocate national policies thatexplicitly allow for the use of non-U.S.positioning sources (for example,Galileo) as part of the infrastructure tomeet aviation performancerequirements.

The FAA fully supports the need forinternational regulators to focus on aglobal interoperability of ADS–Bthrough the continuing development of standards for equipment, applications,flight procedures, and operating rules.The RTCA standards for DO–260B andDO–282B (referenced in TSO–C166band TSO–C154c) were developed withclose international cooperation. TheFAA supports the RTCA/EuropeanOrganization for Civil AviationEquipment (EUROCAE) RequirementsFocus Group, which is internationallycoordinating ADS–B In. Additionally,the FAA actively meets withEUROCONTROL, the Australian CivilAviation Safety Authority, andTransport Canada to internationallycoordinate ADS–B regulation.

The FAA has structured the ADS–BOut program on performancerequirements and not a specificnavigation or positioning source. TheFAA is proposing harmonizedrequirements for aircraft separation toICAO, with the support of Australia,Canada, and EUROCONTROL. TheUnited States is working with otherGNSS providers to ensure systeminteroperability, improve performance,and reduce costs for integrated receiverequipment. This rule does not prohibitthe use of international GNSS; any

navigation source that meets therequirements complies with this rule.

The performance standards for theUAT were developed by RTCA throughinternational cooperation andcoordination. The standards werepublished in DO–282B, (MOPS for UATADS–B). Additionally, DO–282B wasdeveloped in accordance with Annex 10to the convention of international civilaviation. As such, individual states areallowed to invoke these standards astheir own requirements.

T. Backup ATC SurveillanceIn the NPRM, the FAA described an

ADS–B backup strategy that included areduced network of SSRs to supporthigh-density terminal airspace, all enroute airspace above 18,000 feet MSL,and medium-density terminal airspaceabove certain altitudes. In the proposal,the FAA noted that it intends to retainall primary surveillance radar as ameans to mitigate single-aircraft

avionics failures.Several aviation associations, aircarriers, pilots, and various otherorganizations commented on theproposed backup strategy. Thecommenters suggested several potentialalternatives including AutomaticDependent Surveillance—Contract(ADS–C), long range navigation(LORAN), enhanced long rangenavigation (eLORAN), fusion, andmultilateration.

Some commenters, including UPSand United Airlines, recommended thatthe FAA develop a backup system that

not only backs up surveillance, but alsoworks in a fusion process to increase theaccuracy, integrity, and availability of the primary surveillance system. Boeingrecommended that during RAIMoutages, ADS–B could broadcastposition data derived from a flightmanagement system or an inertialnavigation system. Other commentersquestioned whether there was a robustand fully independent airborne- orground-based backup timing system inthe event of GPS timing signal loss. TheDOD contended that the backup must beable to support planned GPS electronictesting and solar flare activity.

Several commenters opposed havingone interdependent service for bothnavigation and surveillance. They

believed that this combination of navigation and surveillance could bedetrimental when a pilot experiences aGPS outage while operating ininstrument meteorological conditions.The ARC recommended that the FAA,in coordination with other Governmentagencies, develop an integratedcommunication navigation and


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58 It is important to recognize that this is aperformance-based rule and does not require GNSS.For the purpose of the backup strategy evaluationthe FAA assumed that users would equip with aGNSS as their position source.

59 The standard for reverting to backupsurveillance is also discussed in H.2, SystemAvailability.

surveillance (CNS) strategy to addressGNSS interference and outages.

Various entities also questioned theprocedures that would be in place foraircraft operating with a NAC P value of less than 9. One individual asked howthe system will accommodate aircraftwithout ADS–B, if an entire broadcastlink is inoperable.

The FAA will provide ATC separation

services for aircraft meeting theminimum ADS–B-required performanceparameters (NAC P , NAC V , NIC, SDA,and SIL) for airspace subject to this rule.If, during flight, an individual aircraftdoes not meet the minimum ADS–B-required performance parameters, thenATC may provide separation servicesusing the backup (for example, radarwhere available and proceduralseparation elsewhere). This transitionwill be seamless because secondarysurveillance data will be one of severalsurveillance sources fused into thedisplay used by ATC.

The ADS–B ground automationcombines or ‘‘ fuses ’’ all availablesurveillance information from ADS–Bwith primary surveillance radar andSSR. This provides a complete or‘‘ fused ’’ picture of all the trafficoperating in a given area. Multi-sensorfusion allows the automation tocombine data from various sensors, anduse the most accurate measurements. Inmost cases, a Kalman Filter Trackeroptimizes the accuracy of trackestimates from multiple sensors. Inaddition to improved aircraft positionaccuracy, data fusion uses all theupdates from multiple sensors, which

increases the overall update rate. TheFAA currently uses practical trackers fordata fusion with the Common-Automated Radar Terminal System andthe Standard Terminal AutomationReplacement System.

If the ADS–B ground infrastructure ora particular broadcast link is out of service, or a sufficient number of aircraftcannot meet the minimum requiredperformance for a given airspace andcontroller workload is adverselyimpacted, ATC will use the backupsystem to provide ATC separationservices for all aircraft in that airspace.Transition to the backup strategy willnot impact the ability of ATC to provideseparation services to the operator.

The FAA completed the Surveillance/Positioning Backup StrategyAlternatives Analysis 58 on January 8,2007. This study included acomprehensive analysis of various

strategies for mitigating the impact of the loss of GPS on ADS–B surveillance.The analysis identified a reducednetwork of SSRs as the recommended

backup for ADS–B. This strategy retainsall existing en route SSRs (150) andapproximately 50 percent of SSRs inhigh-density terminal areas (40).

The FAA assessed numerous

technologies as part of this analysis,including: Multilateration; eLORAN;distance measuring equipment (DME);DME/inertial reference units; satellite-

based augmentation systems; ground- based augmentation systems; andvarious combinations andimplementations of these technologies.The FAA determined the backupstrategy based on the most effectivetradeoff between performance, schedule,and cost factors among airborne andground segments of the NASarchitecture.

This backup strategy will supportcontinued use of the separationstandards in effect today. However, forselect areas experiencing degradedsurveillance coverage during an outage,ATC may increase aircraft separation asoperationally required. 59 The FAAconcludes that these operationalcapabilities are sufficient, given thatloss of required position information isexpected to be a rare event.

In meeting the performance standardsadopted by this rule, an aircraft’snavigation and surveillance functionsmay be dependent on the same position

source. Using GNSS technology forADS–B provides for improvedperformance (i.e., increased update rate,increased accuracy at long range, andcleaner surveillance picture to ATC)over other surveillance systems andallows for a more flexible groundinfrastructure.

The risks posed by this dependencyhave been accepted because thenavigation and surveillance functionshave independent backup systems. Inevaluating the options, the FAAspecifically considered the scenario inwhich the satellite positioning sourcefailed. As a result, the FAA determinedthat an effective backup system couldnot also be satellite-based. The FAAfurther determined that these backupcapabilities ensure sufficient navigationand surveillance capabilities during apositioning source outage and maintainappropriate levels of safety.

U. Privacy The NPRM proposed requiring a

message element to transmit theaircraft’s assigned 24-bit ICAO address.

Many commenters, including AOPAand Rockwell-Collins, strongly arguedagainst ADS–B Out broadcasts of identifiable data, including aircraft tailnumber and operator name. Thesecommenters argued that the informationcould be used to continuously watch allaircraft and ultimately could be used bythe FAA for enforcement or assessinguser fees. Certain commenters argued infavor of retaining the anonymous modefor VFR operations because aircraftidentification is only required for ATCpurposes.

Commenters suggested several alternatives: (1) Use UAT’s privacymessage function (which allows thepilot to select ‘‘ VFR’’ mode) to have theUAT system randomly select a 24-bitICAO address; (2) require manufacturersto design ADS–B systems that archivedata onboard, and advise pilots toarchive the data so there is anindependent data source thatcorroborates government data; and (3)design a system host configurationprotocol to assign transponder codesthrough a unique address when theUAT or 1090 MHz ES is turned on. Theycontended that this would allow anetwork to eliminate system duplicityand guarantee anonymity to the pilot of the aircraft (therefore, the 24-bit Mode Sidentifiers would no longer be needed).

The ARC made threerecommendations regarding privacy: (1)

The FAA should treat the 24-bit ICAOcode assignments as informationcovered under privacy laws, so they areavailable only to authorized personnelor released by the holder; (2) the FAAshould use the anonymity feature of UAT and develop an equivalentanonymity feature for 1090 MHz ES thatwould apply to VFR operations notusing ATC services; and (3) the FAAshould accommodate assignment of the24-bit ICAO codes so that they do noteasily correlate to an aircraft tail numberand they permit aircraft call signs to besomething other than the aircraftregistration number when receivingATC services.

The FAA reviewed all the commentsregarding privacy and notes that most of the commenters specifically addressedVFR operations. The FAA notes thatthere is no right to privacy whenoperating in the NAS. The FAAspecifically designates airspace forwhich the identification of aircraft isnecessary, so that the agency caneffectively separate aircraft. Thetransponder rule specifies that an


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aircraft operating in airspace designatedin § 91.215 must have ATC transponderequipment installed that meets theperformance requirements of TSO–C74b, TSO–C74c, or TSO–C112.

Many GA aircraft are equipped withMode C, which has the capability tosquawk 1200 and meets therequirements of §91.215, withoutspecifically identifying the aircraft.

Most of these commenters are seekingsimilar treatment under ADS–B so thatATC can track the aircraft withoutspecifically identifying the aircraft.

TSO–C154c includes a feature totemporarily and randomly assign a 24-

bit address for UAT-equipped aircraft.This rule does not prohibit the use of this feature. UAT-equipped aircraftconducting VFR operations that havenot filed a flight plan and are notrequesting ATC services may use thisfeature. Although the FAA does notprohibit the anonymity feature,operators using the anonymity featurewill not be eligible to receive ATCservices and will not be able to benefitfrom enhanced ADS–B search andrescue capabilities. TSO–C166b doesnot include a feature to accommodateanonymous 24-bit addresses. Shouldsafety or efficiency of the NAS sorequire, the FAA could initiaterulemaking to prohibit an operator fromusing the anonymity feature.Additionally, if the FAA, incoordination with the Department of Homeland Security (DHS), determinesthat the anonymity feature is anunacceptable risk to security, the FAAcould initiate rulemaking to prohibit anoperator from using the anonymityfeature.

This rule does not implement anytype of user fee. Subsequent agencyrulemaking would be necessary toestablish such fees. Furthermore, thisrule does not affect the process for theFAA assigning the 24-bit ICAO codes.

The FAA has not determined thatarchiving data onboard the aircraft isnecessary for ATC surveillance.However, this rule does not precludemanufacturers from designingequipment with this function.V. Security

Various commenters, including theDOD, commented on the securityaspects of the ADS–B system. Theycontended that, as ADS–B will

broadcast the location and identity of users, malicious parties could monitortransmissions from the aircraft and ATCto obtain information to target and harmthe aircraft. Another commenter statedthat the ADS–B information could beused by an unmanned aircraft to targetpassenger aircraft. Some commenters

alleged that security safeguards areneeded for ADS–B to protect aircraftfrom terrorist attacks.

Other commenters argued that anaircraft’s ADS–B transmissions or GPSposition/timing signals could be subjectto inadvertent or intentionalinterruption or loss of the GPS timingsignal. Several commentersrecommended a planned oversight

feature (for example, requiring ADS–Bground receivers to be licensed) toensure that only authorized personnelaccess the data collected, and that thedata is only accessed for authorizedpurposes. The DOD recommended thatthe FAA work with DHS and the DODto determine ADS–B risks andappropriate countermeasures.

The FAA conducted several analyseson the security aspects of ADS–B. Theseanalyses include the information systemfor collecting data, transmitting andstoring data, as well as risk assessmentson the vulnerability of ADS–B broadcastmessages. All FAA information,including ADS–B transmissionsreceived by the FAA, that is collected,processed, transmitted, stored, ordisseminated in its general supportsystems and applications is subject tocertification and accreditation, underNational Institutes of Standards andTechnology (NIST) informationtechnology standards. It is a continuingprocess that protects the confidentiality,integrity, and availability of theinformation.

The FAA’s Security Certification andAccreditation Procedures (SCAP) weredeveloped in accordance with Federal

law, including: (1) The FederalInformation Security Management Actof 2002, (2) OMB Circular A–130(Management of Federal InformationResources), (3) Federal InformationProcessing Standards 199, and (4) NISTSpecial Publications (SP) 800–37 (Guidefor the Security Certification andAccreditation of Federal InformationSystems), NIST SP 800–53(Recommended Security Controls forFederal Information Systems), and NISTSP 800–53A (Guide for Assessing theSecurity Controls in Federal InformationSystems).

The FAA completed the SCAP for theADS–B system originally in September2008. The FAA completed a new SCAPin October 2009 as a result of changesmade to the ADS–B system. Thisprocess ensures that ADS–B does notintroduce new security weaknesses. Italso ensures that the hardware andsoftware composing the ADS–B systemmeets rigid and well-documentedstandards for infrastructure security.ADS–B meets all qualifications andmandates of this process. As part of the

SCAP, the system is tested annually forsecurity compliance, and every 3 yearsthe system goes through an entirely newSCAP. In addition, the FAA specificallyassessed the vulnerability risk of ADS–B broadcast messages being used totarget air carrier aircraft. Thisassessment contains Sensitive SecurityInformation that is controlled under 49CFR parts 1 and 1520, and its contentis otherwise protected from publicdisclosure. While the agency cannotcomment on the data in this study, itcan confirm, for the purpose of responding to the comments in thisrulemaking proceeding, that using ADS–B data does not subject an aircraft to anyincreased risk compared to the risk thatis experienced today. As part of thisprocess, the FAA forwarded theassessment to its interagency partners,including the DOD, the TransportationSecurity Administration, the FederalBureau of Investigation, the UnitedStates Secret Service, and other

appropriate agencies for review. Theseentities evaluated the modelingapproach, analysis, and risk outcome.They did not identify any reason toinvalidate the analysis whichdetermined that ADS–B data does notincrease an aircraft’s vulnerability. TheFAA commits to annual updates of thisassessment to monitor any changes inthe underlying assumptions in the riskanalysis, and to monitor new threatinformation that becomes available.

The FAA concludes that ADS–Btransmissions would be no moresusceptible to spoofing (that is,

intentionally broadcasting a false target)or intentional jamming than thatexperienced with SSR transmissions(Mode A, C, and S) today. Spoofing of false targets and intentional jammingvery rarely occur with the surveillancesystems in place today.

The ADS–B transmission signals fromaircraft will be fused with surveillancedata from both primary and secondaryradars before it is displayed for ATC.The controllers, therefore, are receivingand viewing a composite of aircraft datafrom multiple surveillance systems. TheFAA does not expect spoofing andjamming to occur during the transitionto using this fused data for surveillance.This is because the automation willreveal the discrepancy between aspoofed or jammed ADS–B target andthe target reported by radar and SSRposition reports. Fusion also providesfor a smooth transition to backupsurveillance if an ADS–B system isexperiencing interference. Furthermore,encryption of any ADS–B data wouldunnecessarily limit its useinternationally.


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The FAA also concludes thatadditional certification andaccreditation of ground equipment willnot be necessary because of the strictSCAP provision certifying that crucialinformation and equipment are notavailable to unauthorized individuals.

The FAA finds no basis at this pointthat ADS–B Out provides any greatersecurity risks to air navigation systems

to the United States. The FAA continuesto meet regularly with DOD and DHSrepresentatives regarding the use of ADS–B information and nationalsecurity issues.W. Alternatives To ADS–B

The NPRM compared: (1) Radar as itexists today, (2) multilateration, and (3)ADS–B. In the NPRM, the FAA’salternatives analysis found radar to bethe most cost-effective solution;however, radar would neither beeffective in supporting air traffic growthover time nor provide the necessarytechnical capabilities to support theNextGen concept of operations.

Several commenters indicated that theexisting radar system is sufficient foroperations. Some commenters suggestedexpanding the radar infrastructure orimplementing an alternative reportingsystem using commercial off-the-shelf technologies that have a means toencode and transmit GPS position data.

Other commenters believed thatmultilateration could provide similar

benefits to ADS–B at a potentially lowercost. Boeing requested that the FAAprovide an analysis explaining itsconclusion that multilateration would

not provide the same level of benefits asADS–B. ATA specifically stated thatthey do not believe multilateration is aviable alternative; however, it canprovide highly accurate position reportsfor surface ADS–B In applications.Several commenters objected to theprohibitive cost of upgrading theavionics with ADS–B because there arecommercial products currently availablethat provide real time weather andtraffic information.

The agency has determined that theimproved accuracy and update rateafforded by ADS–B is a critical segmentof the NextGen infrastructure andcapabilities that offer the opportunity tomake the system more efficient.Specifically, enhanced surveillance datavia ADS–B will improve theperformance of ATC decision-supporttools (URET and TMA) which rely onsurveillance data to make predictions.The end result will be fewer, moreefficient reroutes to avoid potentialconflicts, as well as improved meteringinto the terminal area. This will allowincreased and more efficient use of

OPDs, which have lower energy andemissions profiles. Unlike radar andmultilateration, ADS–B provides moredetailed flight information (for example,update rate, velocity, and heading) thatsupports ground-based merging andspacing tools. These tools use thisinformation to determine optimal tracksfor ATC arrival planning.

FIS–B and TIS–B provide the uplink

of weather and traffic information to thecockpit. Equipping with the necessaryADS–B In avionics (receiver and displaycomponents) is voluntary for operatorsand is not required by the ADS–B rule.The FAA analyzed alternative sourcesfor weather and traffic information.Individually, these alternative sourcesmay be less costly than the ADS–Bsolution. However, the FAA’s analysisshowed that the bundling of surveillance, weather, and trafficinformation is cost-effective for userswho have not already invested inalternative capabilities. The FAA

compared the costs and benefits of ADS–B, multilateration, and radar, aswell as the cost savings for bundlingservices. A report ( ‘‘ Exhibit 300,Attachment 2, Business Case AnalysisReport for Future Surveillance, JRCPhase 2a ’’ ) is available in the docket forthis rulemaking.

In sum, none of the alternatives offersthe range of capabilities nor supportsthe NextGen concept of operations aswell as ADS–B.

X. ADS–B Equipment Scheduled Maintenance

The NPRM did not propose anyadditional continuing airworthinessrequirements associated with theinstallation of ADS–B avionicsequipment. A few commentersquestioned the FAA’s plan forcontinued airworthiness inspections forADS–B equipment.

This final rule does not add anycontinuing airworthiness inspectionrequirements. Transponder-based ADS–B systems will still be required to meetthe requirements of §91.413. However,ADS–B systems, without a transponder,do not have any new inspectionrequirements. The FAA will use the

ground automation system tocontinuously monitor ADS–Bfunctionality, which accomplishes thepurposes of a recurrent inspection.Y. Specific Design Parameters

In the NPRM, the FAA proposedperformance standards for ADS–B Out,

but did not specify any specific designparameters.

Several commenters, including theEAA, and the United States ParachuteAssociation, recommended specific

design parameters for ADS–B avionics,including size, weight, and powerconsumption.

The FAA again notes that this is aperformance-based rule and does notmandate a particular system or designspecifications (including size, weight, orpower consumption). A performance-

based rule provides industry with theopportunity to use innovativeapproaches in designing ADS–Bavionics to meet the needs of theircustomers.

Z. Economic Issues

The FAA updated the cost and benefitestimates in the final regulatory impactanalysis for this rule. For a summary of the final regulatory impact analysis, seeSection III. The full final regulatoryimpact analysis may be found in thedocket for this rulemaking. Thefollowing section discusses commentsthe FAA received on the proposal’sregulatory evaluation. Where

appropriate, the discussion includesinformation on the updated costs and benefits for this final rule.

1. ADS–B Out Equipage CostThe FAA estimated that costs for the

proposed rule would be between $2.3 billion and $8.5 billion. The FAA alsoconsidered that industry would start toincur equipage costs in 2012, rangingfrom $1.27 billion to $7.46 billion. Inthe final rule, the FAA estimates totalcosts to range from $3.3 billion to $7.0

billion, and industry equipage costs torange from $2.5 billion to $6.2 billion.

Several commenters, including ATA,Boeing, British Airways, Delta Airlines,EAA, Honeywell, NBAA, and theRegional Airline Association (RAA),questioned specific cost estimates in theproposal’s economic analysis or askedfor more information about the cost and

benefit estimates. Most of thecommenters believed that equipagecosts for ADS–B Out would exceed theestimates provided in the proposal.

Several commenters, includingAOPA, EAA, Embraer, and the UnitedStates Parachute Association, stated thatthe cost to equip with ADS–B Out wastoo high. Commenters pointed out that,given the value of most GA aircraft, thecost of equipage could represent asignificant percentage of, or possiblyexceed, the current value of the aircraft.Some commenters noted that costs of this magnitude could make recreationalor business flying cost-prohibitive.Some commenters, including FedEx,noted that equipage costs will besignificantly higher for aircraft notcurrently equipped with a certifiedGPS/WAAS position source.


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60 This report was published in August 2007. Acopy of this report is available from the Web sitehttp://www.regulations.gov. To find the report,enter FAA–2007–29305–0013.1 in the search box.

For the proposed rule, the FAAcontacted manufacturers, industryassociations, and ADS–B Out suppliersto estimate ADS–B equipage andmaintenance costs by aircraft model.The proposal included industryestimates for the cost of installation,maintenance, additional weight, and theaddition of ADS–B Out equipment tomeet the performance mandate. Theproposal’s regulatory impact analysisalso assumed that all active airframes inservice would be retrofitted by 2020.

The FAA expects that the increaseddemand for the ADS–B Out equipmentrequired by this performance-based rulewill result in a more competitivemarket, such that the prices maydecrease in the coming years for certainaircraft groups. The FAA alsoanticipates that any investment in ADS–B Out equipage will increase theresidual value of that aircraft and willallow easier access to the regulatedairspace.

The FAA agrees that equippingaircraft with ADS–B Out will cost morefor those aircraft that are not equippedwith a position source capable of providing the necessary accuracy andintegrity. To capture this cost in theproposal, the FAA requested thatindustry categorize large categoryturbojet airplanes by classic, neo-classic,modern, and new production classes, aswell as the existing level of airplaneequipage for each class. However, due tothe confidentiality of cost data, theregulatory evaluation does not presentADS–B-supplier level data details. TheFAA fully acknowledges that thegeneral aviation community will incursignificant costs from this rule.However, this must be balanced againstthe foundation this capability providesin moving toward the NextGeninfrastructure and benefits from itsoverall usage.2. FAA Cost Savings With ADS–B OutCompared to Radar

The FAA considered the followingthree systems for future NASsurveillance: (1) Radar, (2)multilateration, and (3) ADS–B. TheFAA explained in the proposal thatradar was the lowest cost option. Basedon forecasts at the time of the NPRM,the FAA did not expect that radar couldaccommodate the projected increase intraffic.

Several commenters, including EAAand RAA, stated that the ADS–Bprogram would result in a cost savingsto the FAA because it would have lessradar to maintain, operate, and replace.Most of the commenters claimed thatthe ADS–B program would shift costsfrom the FAA to aircraft operators.

The ADS–B program is not expectedto result in a cost savings to the FAAfrom 2009 through 2035. As ADS–B

becomes operational, the FAA plans todecommission some SSR. While thiswill reduce the operational costs of maintaining radar, the FAA will incuradditional costs for ADS–B groundstations. This results in a net increase incost for the FAA.

3. Business Case for ADS–B Out and In

In the NPRM, the FAA estimated thatthe total costs of ADS–B Out and In(excluding avionics for ADS–B In),relative to the radar baseline, wouldrange from $2.8 billion to $9.0 billion.The FAA further estimated that ADS–BOut and In would yield $13.8 billion intotal benefits.

The FAA concluded that ADS–B Outand In would be cost beneficial at apresent value of 7 percent, if: Theavionics costs for ADS–B Out are low($670 million at a 7 percent presentvalue) and the avionics costs for ADS–B In do not exceed $1.85 billion at a 7percent present value.

As stated in the NPRM, ADS–B Outand In would be cost beneficial at a 3percent present value if: (1) Theavionics costs for ADS–B Out are low($950 million at a 3 percent presentvalue) and the avionics costs for ADS–B In do not exceed $5.3 billion at a 3percent present value or (2) the avionicscosts for ADS–B Out are high ($5.35

billion at a 3 percent present value) andthe avionics costs for ADS–B In do notexceed $870 million.

Boeing asked for further clarificationof scenarios in which ADS–B may not

be cost beneficial. Specifically, Boeingreferred to the 3 percent present valueestimate in the NPRM with highavionics costs. Boeing noted that it doesnot believe ADS–B In avionics costs will

be less than ADS–B Out avionics costs.Boeing also asked for the cost beneficialvalues of ADS–B Out and In at a 7percent present value if avionics costsare high.

Boeing suggested that the FAAconduct a thorough cost-benefit analysisfor the ADS–B program, includingaccurate cost estimates for ADS–B In.Boeing further recommended that if theFAA cannot determine the costsassociated with ADS–B In, the FAAshould not include these costs and

benefits in the economic analysis.Boeing also questioned why the FAA

estimated the benefits for ADS–B Outand In at $13.9 billion in the proposal,while the FAA estimated the ADS–BOut and In benefits at $18.5 billion inthe ‘‘ Surveillance and Broadcast

Services Benefits Basis of Estimates ’’ 60 (SBS BOE) report.

The FAA agrees with Boeing that if the costs of ADS–B Out avionics are atthe high end of our estimates and if ADS–B In avionics are more expensivethan ADS–B Out avionics, then the costsestimated for ADS–B Out and In willexceed the quantified benefits, given theassumptions in the economicevaluation. The FAA also notes that ata 7 percent present value with theassumptions in the economic evaluation(i.e., if industry costs for ADS–B Outavionics are at the high end of therange), then ADS–B Out and In will not

be cost-beneficial. The FAA does notagree that the estimates in the regulatoryimpact analysis need to be consistentwith the estimates in the SBS BOEreport. The economic analysis quantifiesthe potential benefits that the FAAexpects to result from adoption of therule. The economic analysis does notinclude benefits that could be realized

without the rule.Specifically, the regulatory impactanalysis did not include benefits fromADS–B in Alaska or for low altitudeoperations in the Gulf of Mexico

because these benefits would occurwithout the rule. The regulatoryevaluation also did not include benefitsrelated to controlled flight into terrain

because terrain avoidance warningsystems currently provide these

benefits. Other benefits that the FAAdid not consider in the proposal, but arein the SBS BOE, include: An estimate of the reduction in FAA subscriptioncharges because of value added servicesand a reduction in costs to obtainweather information.

In addition, the regulatory impactanalysis did not specifically include a

benefit for radar system replacementcost avoidance. Rather, the FAAcompared the total cost of continuingfull radar surveillance (the baseline) tothe cost of providing surveillance withADS–B. This included the costs of gradually discontinuing some radar andcontinuing some radar as a backup. Thelower costs of radar (what is referred toas ‘‘ surveillance cost avoidance ’’ in theSBS BOE) were captured in the costcomparison of radar under the baselineand radar under the ADS–B Outscenario (the rule).

The draft regulatory impact analysisreleased with the NPRM included acost-benefit analysis of ADS–B Outalone, as well as for the scenarios forADS–B Out and In. For the final rule,


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61 This translates to $840 million at a 7 percentpresent value or $1.8 billion at a 3 percent presentvalue.

62 Economic Values For FAA Investment andRegulatory Decisions, A Guide, Final ReportRevised Oct. 3, 2007, GRA Incorporated.

the FAA also queried industry forequipage costs for ADS–B Out and In.Although the FAA initially attempted tocapture the benefits for ADS–B In, uponfurther consideration the agency hasdetermined that the performancerequirements are not sufficientlydeveloped to conduct a meaningfulanalysis. The FAA has not includedADS–B In costs and benefits in the finalregulatory impact analysis.4. Improved En Route Conflict ProbeBenefit Performance

In the NPRM, the FAA estimated the benefit for en route conflict probe at$3.3 billion. 61 To calculate this savings,the FAA estimated the reduction in ATCvectors resulting from improved enroute conflict probe. Then, the FAAattributed this time savings to directaircraft operating costs and thepassenger value of time.

Several commenters questioned theimproved en route conflict probe benefitestimates. The commenters noted thatthe amount of time saved per passengerwas low, compared to other delays inthe overall travel environment (forexample, late arrivals at the airport andwaiting for baggage). Theyrecommended that the FAA delete thepassenger value of time from its benefitestimate.

The FAA does not agree that thepassenger value of time should beremoved from its benefit estimate andtherefore includes it in the finalregulatory impact analysis. There has

been significant discussion aboutwhether small increments of time

should be valued at lower rates thanlarger increments. The present state of theoretical and empirical knowledgedoes not appear to support valuingsmall increments of time less than largerones. 62 5. Capacity Enhancements, AirspaceEfficiency, and Fuel Saving Benefits

In the NPRM, the FAA estimated that between 2017 and 2035, ADS–B would

allow for more efficient handling of potential en route conflicts. In theNPRM, the FAA estimated this wouldsave 410 million gallons of fuel andeliminate 4 million metric tons of carbon dioxide emissions. The FAA alsonoted in the initial regulatory impactanalysis that, during this same timeperiod, continuous descent approaches(now referred to as OPDs), would allowfor a 10 billion pound fuel savings anda 14 million ton reduction in carbondioxide emissions. Furthermore, theFAA noted that optimal routing over theGulf of Mexico would eliminate 300,000metric tons of carbon dioxide emissions

between 2012 and 2035. In the finalregulatory impact analysis, the FAAestimated a net reduction in carbondioxide emissions attributable to therule and calculated a monetary value tothis net reduction. See the fullregulatory impact analysis for details.

A few commenters, including RAA,questioned the cost savings associated

with more efficient flights using ADS–B. Some of these commenters also askedthe FAA to remove the discussion onreduced carbon dioxide emissions

because the efficiency and fuel savingclaims have not been validated.

RAA noted that the FAA hasconsiderable experience justifying rulesthat enhance safety, but suggested thatthe FAA is not experienced in justifyingrules based on increased airspacecapacity and fuel savings. RAA askedthe FAA to validate whether thereduced vertical separation minimum(RVSM) program reduced fuel

consumption, as estimated in the RVSMregulatory evaluation. RAA also notedthat the benefit analysis should quantifythe benefits that ADS–B would provideover current descent procedures enabledwithout ADS–B.

GAMA and an individual commenternoted the environmental impact of airspace modernization. GAMAencouraged the FAA to provideadditional details and quantify the

benefit from fuel savings that the FAAexpects ADS–B surveillance willprovide.

In the proposal’s benefit analysis, theFAA quantified the benefits that ADS–B alone will provide over current,recognized OPD procedures. The agencyagrees that the efficiency benefits are, inpart, conceptual, and with newtechnologies, conceptual efficiency

benefits analysis is the only option.While outside the scope of thisrulemaking, as noted by a commenter,the RVSM program offers an example of how airspace redesign and newtechnological capabilities can result insignificant efficiency and operational(fuel savings) gains.

6. Deriving Benefits From CapstoneImplementation in Alaska

In the NPRM, the FAA explained thatADS–B has been demonstrated and usedin Alaska for terrain and trafficawareness, and that it had a noticeableeffect on safety. Several commentersargued that Capstone is an insufficient

basis to assume benefits from ADS–Bequipage. The commenters noted thatCapstone is a strong component of thejustification for the system; they addedthat a major component of Capstone isthe addition of terrain information andwarnings. Commenters also noted thatthe flight environment in southeastAlaska is unlike any in the lower 48states.

The FAA understands that theconditions in Alaska do not translate tothe continental United States. While theregulatory impact analysis does notinclude any benefits from Capstone, therulemaking action does highlight thepotential benefits derived from moreaccurate and timely positioninginformation from ADS–B.

7. Regional Airline Benefits

In the NPRM, the FAA quantified the benefits as shown in Table 4.

TABLE 4—E STIMATED BENEFITS INCLUDED IN THE NPRM R EGULATORY EVALUATION

Benefit area Benefit 2007M$

Discounted at3%

Discounted at7%

Total Benefits ............................................................................................................................... $9,948.5 $5,484.3 $2,657.7Gulf of Mexico:

High Altitude Operations ...................................................................................................... 2,067.2 1,104.4 509.9More Efficient En Route Separation Delay Savings ............................................................ 1,810.6 946.1 421.3Additional Flights Accommodated Optimal and More Direct Routing .................................. 256.6 158.4 88.6

Improved En Route Conflict Probe Performance ........................................................................ 3,258.1 1,774.0 840.1More Efficient Metering Based on Improved TMA Accuracy ...................................................... 1,746.6 944.9 441.1Increased Ability to Perform Continuous Descent Approaches .................................................. 2,876.7 1,661.0 866.6


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63 The FAA also calculated this midpoint to be$2.1 billion at a 3 percent present value or $1.5

billion at a 7 percent present value.

64 The costs of radar will be about $1 bil lion lesswith ADS–B Out, although the total ground costsof ADS–B Out with the cost to sustain anddecommission select radar will exceed the cost of continuing radar without implementing ADS–B.

RAA expressed concern that regionaloperators do not have equal access tolarge airports; therefore, they will notachieve the same benefits as larger aircarriers. RAA specifically noted that theFAA has not committed to a measurablereduction in aircraft-to-aircraftseparation standards. They believed thatwithout reduced separation standards,the benefits would be localized andwould not apply to regional airlines.RAA also noted that regional aircrafttypically do not carry life rafts and,therefore, they cannot conduct extendedover-water operations. As a result, theywill not benefit from more efficientaircraft separation over the Gulf of Mexico.

The FAA agrees that regionaloperators who cannot operate over theGulf of Mexico will not attain thisseparation benefit. However, the FAAdid not estimate benefits specifically forregional carriers. The agency expectsregional airlines to benefit from ADS–BOut even without reduced aircraft-to-aircraft separation standards. This is

because other benefits, includingimproved en route conflict probeperformance, apply to all aircraft inClass A airspace, including regionalairlines.

8. General Aviation: High EquipageCosts With Little Benefit

In the proposal, the FAA estimatedthat the total cost to equip GA aircraftfrom 2012 through 2035 would rangefrom $1.2 billion to about $4.5 billionwith a mid-point average of nearly $2.9

billion.63

Although the FAA did notspecifically estimate GA benefits in theNPRM, the agency now estimates thatGA could receive up to $200 million inADS–B Out benefits.

Numerous commenters, includingAOPA and EAA, expressed concern thatthe proposed rule would require GAoperators to add costly equipment totheir aircraft, while providing theseoperators with few benefits. GAMAnoted that many of the benefits for GAoperators exist with ADS–B In. Severalof the commenters noted that GAaircraft do not substantially contribute

to delays or congestion in the NAS.They further stated that if ADS–Blessens traffic delays, it will benefit theairlines rather than the GA community.AOPA recommended that the FAA workwith key stakeholders to identify astrategy that either removes low-altitudeairspace users from the proposal orgreatly improves the benefits for them.

The FAA considered three options toresolve the GA cost benefit comments.First, the FAA considered modifyingperformance requirements to reduceequipage costs. Second, the FAAevaluated options to provide additional

benefits to GA operators. Third, theFAA explored tailoring the rule suchthat fewer GA operators would beaffected.

For the first option, the FAAdetermined that opportunities do existfor reducing the equipage costs for GAoperators. In the rule, the FAA bases theperformance requirements solely onATC separation services; whereas in theproposal, the performance requirementswere based on ATC separation servicesand five initial ADS–B In applications.This change eliminated the need forADS–B antenna diversity because theATC separation services can operateeffectively without it and the ADS–BOut benefits can be achieved. Multiplecommenters and the ARC felt that

removing antenna diversity would helpmake the rule cheaper to implement forlight general aviation operators.

For the second option, usingcomments received by the GAcommunity, the FAA has identifiedopportunities to provide additional

benefits to GA operators by expandingADS–B services throughout the NAS toareas not currently serviced. Thus,outside of this rulemaking effort, theFAA intends to explore the costs and

benefits for the following ADS–Benabled service expansions:

(a) Expanding low altitudesurveillance coverage, both in areasreceiving increased collateral coveragefrom the initial ADS–B ground stationinfrastructure and in areas that could

benefit from additional ground stationcoverage.

(b) Providing radar-like terminal ATCservices at airports not currently served.

(c) Providing an automatedmechanism for the closure of IFR flightplans based on the new technologiesability to detect an aircraft’s arrival at itsdestination airport.

(d) Making enhancements to currentsearch and rescue technology andprocedures that will assist rescue

personnel in determining the lastknown location of aircraft that arereported missing.

(e) Providing Flight Service Stations(FSSs) with ADS–B positional displayinformation and assisting in thedevelopment of automation systems thatwill allow for more tailored in flightservice functions.

For the third option, the FAA lookedat tailoring the ADS–B airspace suchthat the number of general aviationaircraft needing to equip would be

minimized. Specifically the FAAconsidered limiting the rule to onlyClass A and B airspace. Although ADS–B surveillance is not as critical to theNexGen goals in lower density airspace,such as Class E airspace above 10,000feet and Class C airspace, ADS–Bequipage for all aircraft in these areas isessential to gaining the overall statedADS–B benefits, realizing savingsassociated with radardecommissioning, 64 the expansion of potential future benefits discussedabove, and moving towards the NextGenconcept of operations. Thus, theairspace subject to this rule remainsunchanged.

AA. Revisions To Other RegulationsSeveral commenters, including ACI–

NA, ACSS, ATA, United Airlines, andUPS, recommended changes to otherregulations. Specifically, theyrecommended that the FAA updatesubpart F of 14 CFR part 25 to include

ADS–B requirements. ACI–NArecommended that the FAA amend 14CFR part 139 to require airport surfacevehicles to equip with ADS–B toprevent runway incursions. Airbusrecommended that the FAA updateadvisory circular (AC) 120–86, AircraftSurveillance Systems and Applications.

This rule only amends the operatingregulations in part 91. At this point, theFAA has not identified any ADS–B Outrequirements for parts 23, 25, 27, and29. The FAA will issue the appropriateaircraft installation and operationalguidance material consistent with therequirements of this rule upon issuanceor shortly thereafter. The FAA isdiscussing with airports and the FederalCommunications Commission whetherADS–B would benefit airport groundvehicles.

III. Regulatory Notices and Analyses

A. Paperwork Reduction Act As required by the Paperwork

Reduction Act of 1995 (44 U.S.C.3507(d)), the FAA submitted a copy of the new (or amended) informationcollection requirement(s) in this finalrule to the Office of Management andBudget (OMB) for its review. OMBassigned the number 2120–0728 inadvance, but has not yet approved thecollection. Affected parties do not haveto comply with the informationcollection requirements until the FAApublishes in the Federal Register noticeof the approval of the control number


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65 ICAO references: Procedures for Air NavigationServices—Air Traffic Management, Doc 4444,Amendment 4, (24/11/05) Procedures for AirNavigation Services—Air Traffic Management; Doc9694, ICAO Manual of Air Traffic Services DataLink Applications; Annex 2, Rules of the Air;Annex 4, Aeronautical Charts; Annex 6 Part II,Operation of Aircraft; Annex 11, Air TrafficServices; Annex 15, Aeronautical InformationServices; Doc 9689, Manual for Determination of Separation Minima; Circular 311, SASP Circular—ADS–B Comparative Assessment; Circular 278,National Plan for CNS/ATM Systems GuidanceMaterial; Annex 10 Vol. IV, Amendment 82,Aeronautical Telecommunications; Doc 9871,Technical Provisions for Mode S Services andExtended Squitter.

assigned by OMB for these informationrequirements. Approval of the controlnumber notifies the public that OMBhas approved these informationcollection requirements under thePaperwork Reduction Act of 1995.

The FAA received comments on theproposed performance requirements forADS–B Out aircraft equipment. Thosecomments are discussed in section II,

Discussion of the Final Rule, elsewherein this preamble. However, the agencyreceived no comments specifically onthe burden associated with collectingaircraft transmissions from the ADS–BOut equipment required by this rule.

A description of the annual burden isshown below.

Use: This final rule will support theinformation needs of the FAA byrequiring avionics equipment thatcontinuously transmits aircraftinformation to be received by the FAA,via automation, for use in providing airtraffic surveillance services.

Respondents: The average number of aircraft that will be equipped annuallyfor the first 3 years—577. The numberof aircraft (general aviation, regional,and majors) that will be equipped by2035: 247,317.

Frequency: ADS–B equipment willcontinuously transmit aircraftinformation in ‘‘ real time ’’ to FAAground receivers. The information iscollected electronically, without input

by a human operator. Old information isoverwritten on a continuous basis.

Annual Burden Estimate: Base-casestart-up cost for an ADS–B Out-compliant transponder: $4,371.09million (in 2009 dollars).An agency may not collect or sponsorthe collection of information, nor may itimpose an information collectionrequirement unless it displays acurrently valid OMB control number.B. International Compatibility

In keeping with U.S. obligationsunder the Convention on InternationalCivil Aviation, it is FAA policy toconform to ICAO SARPs to themaximum extent practicable. ATA,British Airways, and EUROCONTROLrecommended that the FAA harmonizethis rule with the appropriate ICAOSARPs. Considering that the long-termglobal capabilities of ADS–B are not yetfully defined, ICAO SARPs willcontinue to evolve to reflect developingADS–B applications. In addition,current ICAO SARPs for the 1090 MHzES and UAT ADS–B links will beupdated to reflect harmonized changesto both RTCA and EUROCAE minimumperformance standards, as appropriate,for ADS–B Out operations. The FAA hasreviewed the existing ICAO

requirements 65 as related to ADS–B Outoperations and has identified nodifferences with these regulations. TheFAA also will continue to work with theinternational community to ensureharmonization.C. Regulatory Impact Analysis,Regulatory Flexibility Determination,International Trade Impact Assessment,and Unfunded Mandates Assessment

Changes to Federal regulations mustundergo several economic analyses.First, Executive Order 12866 directs thateach Federal agency propose or adopt aregulation only upon a reasoneddetermination that the benefits of theintended regulation justify its costs.Second, the Regulatory Flexibility Actof 1980 (Pub. L. 96–354) requiresagencies to analyze the economicimpact of regulatory changes on smallentities. Third, the Trade AgreementsAct (Pub. L. 96–39) prohibits agenciesfrom setting standards that createunnecessary obstacles to the foreigncommerce of the United States. Indeveloping U.S. standards, this TradeAct requires agencies to considerinternational standards and, whereappropriate, that they be the basis of U.S. standards. Fourth, the UnfundedMandates Reform Act of 1995 (Pub. L.104–4) requires agencies to prepare awritten assessment of the costs, benefits,and other effects of proposed or finalrules that include a Federal mandatelikely to result in the expenditure byState, local, or tribal governments, in theaggregate, or by the private sector, of $100 million or more annually (adjustedfor inflation with a base year of 1995).This portion of the preamblesummarizes the FAA’s analysis of theeconomic impacts of this final rule. TheFAA suggests that readers seekinggreater detail read the full regulatoryimpact analysis, a copy of which has

been placed in the docket for thisrulemaking.

In conducting these analyses, the FAAhas determined that this final rule: (1)Has benefits that justify its costs; (2) isan economically ‘‘ significant regulatory

action ’’ as defined in section 3(f) of Executive Order 12866; (3) is‘‘ significant ’’ as defined in DOT’sRegulatory Policies and Procedures; (4)will have a significant economic impacton a substantial number of smallentities; (5) will not create unnecessaryobstacles to the foreign commerce of theUnited States; and (6) will impose anunfunded mandate on the private sector

but not on state, local, or tribalgovernments. These analyses aresummarized below.

Regulatory Impact AnalysisThe FAA reviewed the following three

alternatives for surveillance and found Alternative 2 (the rule) to be the

preferred alternative:1. Baseline radar —Maintain the

current radar based surveillance systemand replace radar facilities when theywear out;

2. ADS–B—Aircraft operators equip tomeet performance requirements

required by the rule and the FAAprovides surveillance services based ondownlinked aircraft information.

3. Multilateration —The FAA providessurveillance using multilateration.

Key Assumptions• All costs and benefits are

denominated in 2009 dollars.• The final rule will be published in

2010 and have a compliance date of 2020.

• Present value rates are 3% and 7%.• Period of analysis: 2009–2035.

Benefits of the Final Rule

The benefits of the final rule includethe dollar value of savings in fuel, time,net reduction in CO 2 emissions, and theconsumer surplus associated with theadditional flights accommodated

because of the rule. The estimatedquantified benefits of the rule rangefrom $6.8 billion ($2.1 billion at 7%present value) to $8.5 billion ($2.7

billion at 7% present value).

Costs of the Final RuleThe estimated incremental costs of

the final rule range from a low of $3.3 billion ($2.2 billion at 7% present value)to a high of $7.0 billion ($4.1 billion at7% present value). These include coststo the government, as well as to theaviation industry and other users of theNAS, to deploy ADS–B, and areincremental to maintaining surveillancevia current technology (radar). Theaviation industry would begin incurringcosts for avionics equipage in 2012 andwould incur total costs ranging from$2.5 billion ($1.4 billion at 7% presentvalue) to $6.2 billion ($3.3 billion at 7%present value) with an estimated


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midpoint of $4.4 billion ($2.3 billion at7% present value) from 2012 to 2035.Regulatory Flexibility Determinationand Analysis

Introduction and Purpose of thisAnalysis

The Regulatory Flexibility Act of 1980(Pub. L. 96–354) (RFA) establishes ‘‘ as aprinciple of regulatory issuance thatagencies shall endeavor, consistent withthe objectives of the rule and of applicable statutes, to fit regulatory andinformational requirements to the scaleof the businesses, organizations, andgovernmental jurisdictions subject toregulation. To achieve this principle,agencies are required to solicit andconsider flexible regulatory proposalsand to explain the rationale for theiractions to assure that such proposals aregiven serious consideration. ’’ The RFAcovers a wide range of small entities,including small businesses, not-for-profit organizations, and small

governmental jurisdictions.Agencies must perform a review todetermine whether a rule will have asignificant economic impact on asubstantial number of small entities. If the agency determines that the rule willhave such an impact, the agency mustprepare a regulatory flexibility analysisas described in the RFA. Section 603 of the RFA requires agencies to prepareand make available for public commenta final regulatory flexibility analysis(FRFA) describing the impact of finalrules on small entities. As the FAAAdministrator, I certify that this rulewill have a significant economic impacton a substantial number of smallentities. The purpose of this analysis isto provide the reasoning underlying thisFAA determination.

Section 603(b) of the RFA specifiesthe content of a FRFA.

Each FRFA must contain:• A description of the reasons why

action by the agency is beingconsidered;

• A succinct statement of theobjectives of, and legal basis for, thefinal rule;

• A description and an estimate of thenumber of small entities to which the

rule will apply;• A description of the projectedreporting, record keeping and othercompliance requirements of the finalrule including an estimate of the classesof small entities which will be subjectto the requirement and the type of professional skills necessary forpreparation of the report or record;

• An identification, to the extentpracticable, of all relevant Federal ruleswhich may duplicate, overlap, orconflict with the final rule;

• A description of any significantalternatives to the final rule whichaccomplish the stated objectives of applicable statutes and minimize anysignificant economic impact of the finalrule on small entities.

• A summary of significant issuesraised by public comments in responseto the initial regulatory flexibilityanalysis and how the agency resolved

those comments.Reasons Why the Final Rule is BeingPromulgated

Public Law 108–176, referred to as‘‘ The Century of AviationReauthorization Act, ’’ was enactedDecember 12, 2003 (Pub. L. 108–176).This law set forth requirements andobjectives for transforming the airtransportation system to progress furtherinto the 21st century. Section 709 of thisstatute required the Secretary of Transportation to establish in the FAAa Joint Planning and DevelopmentOffice (JPDO) to manage work related toNextGen. Among its statutorily definedresponsibilities, the JPDO coordinatesthe development and use of newtechnologies to ensure that, whenavailable, they may be used to thefullest potential in aircraft and in the airtraffic control system.

The FAA, the National Aeronauticsand Space Administration (NASA), andthe Departments of Commerce, Defense,and Homeland Security have launchedan effort to align their resources todevelop and further NextGen. The goalsof NextGen, as stated in section 709,that are addressed by this final rule

include: (1) Improving the level of safety, security, efficiency, quality, andaffordability of the NAS and aviationservices; (2) Taking advantage of datafrom emerging ground- and space-basedcommunications, navigation, andsurveillance technologies; (3) Beingscalable to accommodate and encouragesubstantial growth in domestic andinternational transportation andanticipate and accommodate continuingtechnology upgrades and advances; and(4) Accommodating a wide range of aircraft operations, including airlines,air taxis, helicopters, GA, and

unmanned aerial vehicles.The JPDO was also charged to createand carry out an integrated plan forNextGen. The NextGen Integrated Plan,transmitted to Congress on December12, 2004, ensures that the NextGensystem meets the air transportationsafety, security, mobility, efficiency andcapacity needs beyond those currentlyincluded in the FAA’s OperationalEvolution Plan (OEP).

As described in the NextGenIntegrated Plan, the current approach to

air transportation ( i.e., ground basedradars tracking congested flyways andpassing information among the controlcenters for the duration of flights) is

becoming operationally obsolete. Thecurrent system is increasinglyinefficient, and despite decreases in airtraffic, still subject to significant delays.Resumption of growth will onlyaggravate congestion and delays, giventhe capabilities of the present system.The current method of handling airtraffic flow will not be able to adapt tothe volumes, density, and approach tomanaging air traffic in the future. Theneed for significant improvementstowards operational efficiency andreduced environmental impacts, as wellas resumed growth, will createsignificant challenges. Moreover, thediversity of aircraft is forecast to growas the use of unmanned aircraft systemsand very light jets are developed forspecial operations.

The FAA believes that ADS–Btechnology is a key component inachieving many of the goals set forth inthe NextGen Integrated Plan. This finalrule is a major step toward strategically‘‘ establishing an agile air traffic systemthat accommodates future requirementsand readily responds to shifts indemand from all users, ’’ by embracing anew approach to surveillance that canlead to greater and more efficientairspace use. ADS–B technology notonly assists in the transition to a systemwith less dependence on groundinfrastructure and facilities, but alsocreates capabilities for precision andaccuracy, which in turn will make thesystem more operationally andenvironmentally efficient.Statement of the Legal Basis andObjectives

The FAA’s authority to issue rulesregarding aviation safety is found inTitle 49 of the United States Code.Subtitle I, Section 106, Federal AviationAdministration, describes the authorityof the FAA Administrator. Subtitle VII,Aviation Programs, describes in moredetail the scope of the agency’sauthority.

This rulemaking is promulgatedunder the authority described inSubtitle VII, Part A, Subpart I, Section40103, Sovereignty and Use of Airspace,and Subpart III, Section 44701, GeneralRequirements. Under section 40103, theFAA is charged with prescribingregulations on: (1) The flight of aircraft,including regulations on safe altitudes;(2) the navigation, protection, andidentification of aircraft; and (3) the safeand efficient use of the navigableairspace. Under section 44701, the FAAis charged with promoting safe flight of


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civil aircraft in air commerce byprescribing regulations for practices,methods, and procedures theAdministrator finds necessary for safetyin air commerce.

This final rule is within the scope of sections 40103 and 44701 because itpromulgates aircraft performancerequirements to meet advancedsurveillance needs that willaccommodate projected increases inoperations within the NAS. As moreaircraft operate within the U.S. airspace,improved surveillance performance isnecessary to continue balancing airtransportation growth with the agency’smandate for a safe and efficient airtransportation system.Projected Reporting, Record Keepingand Other Requirements

As required by the PaperworkReduction Act of 1995 (44 U.S.C.3507(d)), the FAA submitted a copy of the new information collectionrequirements in this final rule to theOffice of Management and Budget for itsreview. See discussion in Section IIIelsewhere in this preamble.

Overlapping, Duplicative, orConflicting Federal Rules

The FAA is not aware that the finalrule will overlap, duplicate or conflictwith existing Federal rules.

Significant Issues Raised by PublicComments to the Initial RegulatoryFlexibility Analysis

In the NPRM, the FAA addressed theimpact of the proposed rule on small-

business part 91, 121, and 135 operatorswith less than 1,500 employees. Theproposal noted that a substantialnumber of small entities would besignificantly affected by the proposedrule.

One individual commented andchallenged the assumption that onlysmall businesses directly involved inaviation would be affected. Thecommenter explained that many

businesses use aircraft indirectly intheir operations and that higher aircraftequipage costs will affect overall

business costs. The commenter believedthat one half of all non-turbine GAaircraft are involved in small businessactivity.

Publicly available data regardinginternal company financial statistics forGA operators is limited. Therefore, theFAA estimated the financial impact byobtaining a sample population of GAoperators from (1) the U.S. DOT Form41 filings, (2) World Aviation Directory,and (3) ReferenceUSA. The FAAapplied this sample to U.S. CensusBureau data on the Small Business

Administration Web site. This was doneto develop an estimate of the totalnumber of small businesses affected bythe proposed rule.

The FAA agrees that GA operators useairplanes for indirect business use andhas determined that this final rule willhave a significant impact on asubstantial number of small businesses.Estimated Number of Small FirmsPotentially Impacted

Under the RFA, the FAA mustdetermine whether a rule significantlyaffects a substantial number of smallentities. This determination is typically

based on small entity size and costthresholds that vary depending on theaffected industry.

Using the size standards from theSmall Business Administration for AirTransportation and AircraftManufacturing, the FAA definedcompanies as small entities if they havefewer than 1,500 employees.

The FAA considered the economicimpact on small-business part 91, 121,and 135 operators. Many of the GAaircraft that are operating under part 91are not for hire or flown for profit, so theFAA does not include these operators inits small business impact analysis.

This final rule will become effectivein 2020. Although the FAA forecaststraffic and air carrier fleets to 2040, ourforecasts are of a generic nature and donot forecast the number of smallentities. These forecasts also do notestimate whether an operator will still

be in business or will be a small business entity. Therefore the FAA uses

current U.S. operator’s revenues andapplies the industry-provided costs todetermine if this final rule will have asignificant impact on a substantialnumber of small entity operators.

The FAA obtained a list of part 91,121 and 135 U.S. operators from theFAA Flight Standards Service. Usinginformation provided by the U.S. DOTForm 41 filings, World AviationDirectory, and ReferenceUSA, the FAAeliminated operators that are subsidiary

businesses of larger businesses and businesses with more than 1,500employees from the list of small entities.In many cases, the employment andannual revenue data are not public, sothe FAA did not include thesecompanies in its analysis. For theremaining businesses, the FAA obtainedcompany revenue and employment fromthe above three sources.

The methodology discussed aboveresulted in a list of 34 U.S. part 91, 121and 135 operators, with less than 1,500employees, who operate 341 airplanes.Due to the sparse amount of publiclyavailable data on internal company

financial statistics for small entities, itwas not feasible to estimate the totalpopulation of small entities affected bythis final rule. The total population of U.S. part 91, 121 and 135 operators,with less than 1,500 employees, has thepotential to be large. We used thissample set of small business operatorsto develop percentage estimates to applyto the U.S. Census Bureau data toestimate the population.These 34 U.S. small entity operatorsare a representative sample. The samplewas used to assess the cost impact onthe total population of small businesseswho operate aircraft affected by thisfinal rulemaking. This representativesample was then applied to the U.S.Census Bureau data on the SmallBusiness Administration’s Web site todevelop an estimate of the total numberof affected small business entities.

The U.S. Census Bureau data listssmall entities in the air transportationindustry that employ less than 500employees. Other small businesses mayown aircraft and may not be included inthe U.S. Census Bureau airtransportation industry category.Therefore our estimate of the number of small entities affected by this final rulewill likely be understated. The estimateof the total number of affected smallentities is developed below.Cost and Affordability for SmallEntities

To assess the cost impact to small business part 91, 121 and 135 operators,the FAA contacted manufacturers,industry associations, and ADS–B

equipage providers to estimate ADS–Bequipage costs. The FAA requestedestimates of airborne installation costs,

by aircraft model, for the outputparameters listed in the ‘‘ EquipmentSpecifications ’’ section of the RegulatoryImpact Analysis.

To satisfy the manufacturers’ requestto keep individual aircraft pricingconfidential, the FAA calculated low,

baseline, and high range of costs byequipment class. The baseline estimateequals the average of the low and highindustry cost estimates. The dollar valueranges consist of a wide variety of avionics within each aircraft group. Theaircraft architecture within eachequipment group can vary, causingdifferent carriage, labor, and wiringrequirements for the installation of ADS–B. Volume discounting, versussingle line purchasing, also affects thedollar value ranges. On the low end, thedollar value may represent a softwareupgrade or original equipmentmanufacturer (OEM) option change. Onthe high end, the dollar value mayrepresent a new installation of upgraded


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avionic systems necessary to assureaccuracy, reliability and safety. TheFAA used the estimated baseline dollarvalue cost by equipment class indetermining the impact to small

business entities.The FAA estimated each operator’s

total compliance cost as follows:Multiplying the baseline dollar valuecost (by equipment class) by the number

of aircraft each small business operatorcurrently has in its fleet. The FAAsummed these costs by equipment classand group. The FAA then measured theeconomic impact on small entities bydividing the estimated baseline dollarvalue compliance cost for their fleet bythe small entity’s annual revenue.

Each equipment group operated by asmall entity may have to comply withdifferent requirements in the final rule,depending on the state of the aircraft’savionics. In the ‘‘ ADS–B Out EquipageCost Estimate ’’ section of the RegulatoryImpact Analysis, the FAA details itsmethodology to estimate operators’ totalcompliance cost by equipment group.

For small entity operators in thesample population of 34 small aviationentities, the ADS–B cost is estimated tobe: (1) Greater than 2% of annualrevenues for about 35% of the operators;and (2) greater than 1% of annualrevenues for about 54% of the operators.Applying these percentages to the airtransportation industry category of the2006 U.S. Census Bureau data, theADS–B cost is estimated to be: (1)Greater than 2% of annual revenues forat least 1,015 small entities; and (2)greater than 1% of annual revenues forat least 1,562 small entity operators.As a result of the above analysis, theFAA has determined that a substantialnumber of small entities will besignificantly affected by the rule. Everysmall entity that operates an aircraft inthe airspace defined by this final rulewill be required to install ADS–B outequipage and therefore will be affected

by this rulemaking.Business Closure Analysis

For commercial operators, the ratio of costs to annual revenue shows that 7 of 34 small business air operator firmswould have ratios in excess of 5%.Since many of the other commercialsmall business air operator firms do notmake their annual revenue publiclyavailable, it is difficult to assess thefinancial impact of this final rule ontheir business. To fully assess whetherthis final rule could force a small entityinto bankruptcy requires more financialinformation than is publicly available.

In the NPRM, the FAA requestedcomment and supporting justification,from small entities, to assist the FAA in

determining the degree of hardship thefinal rule will have on these entities.Comments were also requested onfeasible alternative methods of compliance. The FAA did not receiveany comments specific to this request.

Competitive Analysis

The aviation industry is an extremelycompetitive industry with slim profitmargins. The number of operators whoentered the industry and have stoppedoperations because of mergers,acquisitions, or bankruptcy litters thehistory of the aviation industry.

The FAA analyzed five years of operating profits for the affected small-entity operators listed above, and wasable to determine the operating profitfor 18 of the 34 small business entities.The FAA discovered that the averageoperating profit for 33% of these 18affected operators was negative. Onlyfour of the 18 affected operators hadaverage annual operating profits that

exceeded $10,000,000.In this competitive industry, costincreases imposed by this regulationwill be hard to recover by raising prices,especially by those operators showingan average five-year negative operatingprofit. Further, large operators may beable to negotiate better pricing fromoutside firms for inspections andrepairs, so small operators may need toraise their prices more than largeoperators. These factors make it difficultfor small operators to recover theircompliance costs by raising prices. If small operators cannot recover all the

additional costs imposed by thisregulation, market shares could shift tothe large operators.

Small operators successfully competein the aviation industry by providingunique services and controlling costs.The extent to which affected smallentities operate in niche markets willaffect their ability to pass on costs.Currently small operators are muchmore profitable than established majorscheduled carriers. This final rule willoffset some of the advantages of lowercapital costs of older aircraft.

Overall, in terms of competition, thisrulemaking reduces small operators’ability to compete.

Disproportionality Analysis

The disproportionately higher impactof the final rule on the fleets of smalloperators results in disproportionatelyhigher costs to small operators. Due tothe potential of fleet discounts, largeoperators may be able to negotiate betterpricing from outside sources forinspections, installation, and ADS–Bhardware purchases.

Based on the percent of potentiallyaffected current airplanes over theanalysis period, small U.S. businessoperators may bear a disproportionateimpact from the final rule.

Analysis of Alternatives

Alternative OneThe status quo alternative has

compliance costs to continue theoperation and commissioning of radarsites. The FAA rejected this status quoalternative because it is becomingoperationally obsolete to use ground-

based radars to track congested airwaysand pass information among controlcenters for the duration of flights. Thecurrent system is not able to upgrade tothe NextGen capabilities, noraccommodate the estimated increases inair traffic, which would result inmounting delays or limitations inservice for many areas.

Alternative Two

Alternative Two would employ atechnology called multilateration.Multilateration is a separate type of secondary surveillance system that isnot radar-based and has limiteddeployment in the U.S. At a minimum,multilateration requires at least fourground stations to deliver the samevolume of coverage and integrity of information as ADS–B, because of theneed to ‘‘ triangulate ’’ the aircraft’sposition.

Multilateration is a process thatdetermines aircraft position by using thedifference in time of arrival of a signal

from an aircraft at a series of receiverson the ground. Multilateration meets theneed for accurate surveillance and isless costly than ADS–B (however, morecostly than radar), but cannot achievethe same level of benefits as ADS–B,such as system capacity andenvironmental improvements.Multilateration would provide the same

benefits as radar, but the FAA estimatesthat the cost of providingmultilateration (including the cost tosustain radar until multilateration isoperational), would exceed the cost tocontinue full radar surveillance.

Alternative ThreeAlternative Three would provide

relief by having the FAA provide anexemption to small air carriers from allrequirements of this rule. Thisalternative would mean that small aircarriers would rely on the status quoground-based radars to track their flightsand pass information among controlcenters for the duration of the flights.

As discussed previously, ADS–B Outcannot be used effectively as the


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Anyone is able to search theelectronic form of all commentsreceived into any of our dockets by thename of the individual submitting thecomment (or signing the comment, if submitted on behalf of an association,

business, labor union, etc. ). You mayreview DOT’s complete Privacy Actstatement in the Federal Registerpublished on April 11, 2000 (Volume65, Number 70; Pages 19477–78) or youmay visit http://DocketsInfo.dot.gov.

Small Business Regulatory EnforcementFairness Act

The Small Business RegulatoryEnforcement Fairness Act (SBREFA) of 1996 requires the FAA to comply withsmall entity requests for information oradvice about compliance with statutesand regulations within its jurisdiction. If you are a small entity and you have aquestion regarding this document, youmay contact your local FAA official, orthe person listed under the FOR FURTHER INFORMATION CONTACT

heading at the beginning of the preamble. You can findout more about SBREFA on the Internetat http://www.faa.gov/ regulations _ policies/rulemaking/ sbre _ act/.

List of Subjects in 14 CFR Part 91Aircraft, Airmen, Air traffic control,

Aviation safety, Incorporation byReference, Reporting, and recordkeepingrequirements.

The AmendmentI In consideration of the foregoing, theFederal Aviation Administrationamends chapter I of 14 CFR as follows:

PART 91—GENERAL OPERATING ANDFLIGHT RULES

I 1. The authority citation for part 91continues to read as follows:

Authority: 49 U.S.C. 106(g), 1155, 40103,40113, 40120, 44101, 44111, 44701, 44704,44709, 44711, 44712, 44715, 44716, 44717,44722, 46306, 46315, 46316, 46504, 46506–46507, 47122, 47508, 47528–47531, articles12 and 29 of the Convention on InternationalCivil Aviation (61 stat. 1180).

I 2. Amend §91.1 by revising paragraph

(b) to read as follows:§ 91.1 Applicability.* * * * *

(b) Each person operating an aircraftin the airspace overlying the waters

between 3 and 12 nautical miles fromthe coast of the United States mustcomply with §§91.1 through 91.21;§§ 91.101 through 91.143; §§ 91.151through 91.159; §§ 91.167 through91.193; § 91.203; § 91.205; §§91.209through 91.217; § 91.221, § 91.225;

§§ 91.303 through 91.319; §§ 91.323through 91.327; § 91.605; § 91.609;§§ 91.703 through 91.715; and § 91.903.* * * * *I 3. Amend §91.130 by revisingparagraph (d) to read as follows:

§ 91.130 Operations in Class C airspace.* * * * *

(d) Equipment requirements. Unlessotherwise authorized by the ATC havingjurisdiction over the Class C airspacearea, no person may operate an aircraftwithin a Class C airspace areadesignated for an airport unless thataircraft is equipped with the applicableequipment specified in § 91.215, andafter January 1, 2020, §91.225.* * * * *I 4. Amend §91.131 by revisingparagraph (d) to read as follows:

§ 91.131 Operations in Class B airspace.* * * * *

(d) Other equipment requirements. Noperson may operate an aircraft in a ClassB airspace area unless the aircraft isequipped with—

(1) The applicable operatingtransponder and automatic altitudereporting equipment specified in§ 91.215 (a), except as provided in§ 91.215 (e), and

(2) After January 1, 2020, theapplicable Automatic DependentSurveillance-Broadcast Out equipmentspecified in § 91.225.I 5. Amend §91.135 by revisingparagraph (c) to read as follows:

§ 91.135 Operations in Class A airspace.* * * * *

(c) Equipment requirements. Unlessotherwise authorized by ATC, no personmay operate an aircraft within Class Aairspace unless that aircraft is equippedwith the applicable equipment specifiedin § 91.215, and after January 1, 2020,§ 91.225.* * * * *I 6. Amend §91.217 by redesignatingparagraphs (a) through (c) as paragraphs(a)(1) through (a)(3), redesignating theintroductory text as paragraph (a)introductory text, and by adding

paragraph (b) to read as follows:§ 91.217 Data correspondence betweenautomatically reported pressure altitudedata and the pilot’s altitude reference.* * * * *

(b) No person may operate anyautomatic pressure altitude reportingequipment associated with a radar

beacon transponder or with ADS–B Outequipment unless the pressure altitudereported for ADS–B Out and Mode C/Sis derived from the same source for

aircraft equipped with both atransponder and ADS–B Out.I 7. Add §91.225 to read as follows:

§ 91.225 Automatic DependentSurveillance-Broadcast (ADS–B) Outequipment and use.

(a) After January 1, 2020, and unlessotherwise authorized by ATC, no personmay operate an aircraft in Class A

airspace unless the aircraft hasequipment installed that—(1) Meets the requirements in TSO–

C166b, Extended Squitter AutomaticDependent Surveillance-Broadcast(ADS–B) and Traffic InformationService-Broadcast (TIS–B) EquipmentOperating on the Radio Frequency of 1090 Megahertz (MHz); and

(2) Meets the requirements of § 91.227.

(b) After January 1, 2020, and unlessotherwise authorized by ATC, no personmay operate an aircraft below 18,000feet MSL and in airspace described inparagraph (d) of this section unless theaircraft has equipment installed that—

(1) Meets the requirements in—(i) TSO–C166b; or(ii) TSO–C154c, Universal Access

Transceiver (UAT) AutomaticDependent Surveillance-Broadcast(ADS–B) Equipment Operating on theFrequency of 978 MHz;

(2) Meets the requirements of § 91.227.

(c) Operators with equipmentinstalled with an approved deviationunder §21.618 of this chapter also arein compliance with this section.

(d) After January 1, 2020, and unless

otherwise authorized by ATC, no personmay operate an aircraft in the followingairspace unless the aircraft hasequipment installed that meets therequirements in paragraph (b) of thissection:

(1) Class B and Class C airspace areas;(2) Except as provided for in

paragraph (e) of this section, within 30nautical miles of an airport listed inappendix D, section 1 to this part fromthe surface upward to 10,000 feet MSL;

(3) Above the ceiling and within thelateral boundaries of a Class B or ClassC airspace area designated for an airportupward to 10,000 feet MSL;

(4) Except as provided in paragraph(e) of this section, Class E airspacewithin the 48 contiguous states and theDistrict of Columbia at and above 10,000feet MSL, excluding the airspace at and

below 2,500 feet above the surface; and(5) Class E airspace at and above 3,000

feet MSL over the Gulf of Mexico fromthe coastline of the United States out to12 nautical miles.

(e) The requirements of paragraph (b)of this section do not apply to any


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aircraft that was not originallycertificated with an electrical system, orthat has not subsequently been certifiedwith such a system installed, including

balloons and gliders. These aircraft mayconduct operations without ADS–B Outin the airspace specified in paragraphs(d)(2) and (d)(4) of this section.Operations authorized by this sectionmust be conducted—

(1) Outside any Class B or Class Cairspace area; and(2) Below the altitude of the ceiling of

a Class B or Class C airspace areadesignated for an airport, or 10,000 feetMSL, whichever is lower.

(f) Each person operating an aircraftequipped with ADS–B Out must operatethis equipment in the transmit mode atall times.

(g) Requests for ATC authorizeddeviations from the requirements of thissection must be made to the ATCfacility having jurisdiction over theconcerned airspace within the timeperiods specified as follows:

(1) For operation of an aircraft with aninoperative ADS–B Out, to the airport of ultimate destination, including anyintermediate stops, or to proceed to aplace where suitable repairs can bemade or both, the request may be madeat any time.

(2) For operation of an aircraft that isnot equipped with ADS–B Out, therequest must be made at least 1 hour

before the proposed operation.(h) The standards required in this

section are incorporated by referencewith the approval of the Director of theOffice of the Federal Register under 5

U.S.C. 552(a) and 1 CFR part 51. Allapproved materials are available forinspection at the FAA’s Office of Rulemaking (ARM–1), 800Independence Avenue, SW.,Washington, DC 20590 (telephone 202–267–9677), or at the National Archivesand Records Administration (NARA).For information on the availability of this material at NARA, call 202–741–6030, or go to http://www.archives.gov/

federal _ register/code _ of _ federal _regulations/ibr _ locations.html. Thismaterial is also available from thesources indicated in paragraphs (h)(1)and (h)(2) of this section.

(1) Copies of Technical StandardOrder (TSO)–C166b, Extended SquitterAutomatic Dependent Surveillance-Broadcast (ADS–B) and TrafficInformation Service-Broadcast (TIS–B)Equipment Operating on the RadioFrequency of 1090 Megahertz (MHz)(December 2, 2009) and TSO–C154c,Universal Access Transceiver (UAT)Automatic Dependent Surveillance-Broadcast (ADS–B) EquipmentOperating on the Frequency of 978 MHz

(December 2, 2009) may be obtainedfrom the U.S. Department of Transportation, Subsequent DistributionOffice, DOT Warehouse M30, ArdmoreEast Business Center, 3341 Q 75thAvenue, Landover, MD 20785;telephone (301) 322–5377. Copies of TSO –C166B and TSO–C154c are alsoavailable on the FAA’s Web site, athttp://www.faa.gov/aircraft/air _ cert/ design _ approvals/tso/. Select the link‘‘ Search Technical Standard Orders. ’’

(2) Copies of Section 2, EquipmentPerformance Requirements and TestProcedures, of RTCA DO–260B,Minimum Operational PerformanceStandards for 1090 MHz ExtendedSquitter Automatic DependentSurveillance-Broadcast (ADS–B) andTraffic Information Services-Broadcast(TIS–B), December 2, 2009 (referencedin TSO–C166b) and Section 2,Equipment Performance Requirementsand Test Procedures, of RTCA DO–282B, Minimum OperationalPerformance Standards for UniversalAccess Transceiver (UAT) AutomaticDependent Surveillance-Broadcast(ADS–B), December 2, 2009 (referencedin TSO C–154c) may be obtained fromRTCA, Inc., 1828 L Street, NW., Suite805, Washington, DC 20036–5133,telephone 202–833–9339. Copies of RTCA DO–260B and RTCA DO–282Bare also available on RTCA Inc.’s Website, at http://www.rtca.org/onlinecart/ allproducts.cfm.I 8. Add §91.227 to read as follows:

§ 91.227 Automatic DependentSurveillance-Broadcast (ADS–B) Out

equipment performance requirements.(a) Definitions. For the purposes of

this section:ADS–B Out is a function of an

aircraft’s onboard avionics thatperiodically broadcasts the aircraft’sstate vector (3-dimensional position and3-dimensional velocity) and otherrequired information as described inthis section.

Navigation Accuracy Category for Position (NAC P ) specifies the accuracyof a reported aircraft’s position, asdefined in TSO–C166b and TSO–C154c.

Navigation Accuracy Category for

Velocity (NAC V ) specifies the accuracyof a reported aircraft’s velocity, asdefined in TSO–C166b and TSO–C154c.

Navigation Integrity Category (NIC)specifies an integrity containmentradius around an aircraft’s reportedposition, as defined in TSO–C166b andTSO–C154c.

Position Source refers to theequipment installed onboard an aircraftused to process and provide aircraftposition (for example, latitude,longitude, and velocity) information.

Source Integrity Level (SIL) indicatesthe probability of the reportedhorizontal position exceeding thecontainment radius defined by the NICon a per sample or per hour basis, asdefined in TSO–C166b and TSO–C154c.

System Design Assurance (SDA)indicates the probability of an aircraftmalfunction causing false or misleadinginformation to be transmitted, asdefined in TSO–C166b and TSO–C154c.Total latency is the total time betweenwhen the position is measured andwhen the position is transmitted by theaircraft.

Uncompensated latency is the timefor which the aircraft does notcompensate for latency.

(b) 1090 MHz ES and UAT Broadcast Links and Power Requirements —

(1) Aircraft operating in Class Aairspace must have equipment installedthat meets the antenna and poweroutput requirements of Class A1, A1S,A2, A3, B1S, or B1 equipment as

defined in TSO–C166b, ExtendedSquitter Automatic DependentSurveillance-Broadcast (ADS–B) andTraffic Information Service-Broadcast(TIS–B) Equipment Operating on theRadio Frequency of 1090 Megahertz(MHz).

(2) Aircraft operating in airspacedesignated for ADS–B Out, but outsideof Class A airspace, must haveequipment installed that meets theantenna and output power requirementsof either:

(i) Class A1, A1S, A2, A3, B1S, or B1as defined in TSO–C166b; or

(ii) Class A1H, A1S, A2, A3, B1S, orB1 equipment as defined in TSO–C154c,Universal Access Transceiver (UAT)Automatic Dependent Surveillance–Broadcast (ADS–B) EquipmentOperating on the Frequency of 978MHz.

(c) ADS–B Out PerformanceRequirements for NAC P, NAC V , NIC,SDA, and SIL —

(1) For aircraft broadcasting ADS–BOut as required under § 91.225 (a) and(b)—

(i) The aircraft’s NAC P must be lessthan 0.05 nautical miles;

(ii) The aircraft’s NAC V must be less

than 10 meters per second;(iii) The aircraft’s NIC must be lessthan 0.2 nautical miles;

(iv) The aircraft’s SDA must be 2; and(v) The aircraft’s SIL must be 3.(2) Changes in NAC P , NAC V , SDA,

and SIL must be broadcast within 10seconds.

(3) Changes in NIC must be broadcastwithin 12 seconds.

(d) Minimum Broadcast MessageElement Set for ADS–B Out. Eachaircraft must broadcast the following


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information, as defined in TSO–C166bor TSO–C154c. The pilot must enterinformation for message elements listedin paragraphs (d)(7) through (d)(10) of this section during the appropriatephase of flight.

(1) The length and width of theaircraft;

(2) An indication of the aircraft’slatitude and longitude;

(3) An indication of the aircraft’s barometric pressure altitude;(4) An indication of the aircraft’s

velocity;(5) An indication if TCAS II or ACAS

is installed and operating in a mode thatcan generate resolution advisory alerts;

(6) If an operable TCAS II or ACAS isinstalled, an indication if a resolutionadvisory is in effect;

(7) An indication of the Mode 3/Atransponder code specified by ATC;

(8) An indication of the aircraft’s callsign that is submitted on the flight plan,or the aircraft’s registration number,

except when the pilot has not filed aflight plan, has not requested ATCservices, and is using a TSO–C154c self-assigned temporary 24-bit address;

(9) An indication if the flightcrew hasidentified an emergency, radiocommunication failure, or unlawfulinterference;

(10) An indication of the aircraft’s‘‘ IDENT ’’ to ATC;

(11) An indication of the aircraftassigned ICAO 24-bit address, exceptwhen the pilot has not filed a flightplan, has not requested ATC services,and is using a TSO–C154c self-assignedtemporary 24-bit address;

(12) An indication of the aircraft’semitter category;

(13) An indication of whether anADS–B In capability is installed;

(14) An indication of the aircraft’sgeometric altitude;

(15) An indication of the NavigationAccuracy Category for Position (NAC P );

(16) An indication of the NavigationAccuracy Category for Velocity (NAC V );

(17) An indication of the NavigationIntegrity Category (NIC);

(18) An indication of the SystemDesign Assurance (SDA); and

(19) An indication of the Source

Integrity Level (SIL).(e) ADS–B Latency Requirements —

(1) The aircraft must transmit itsgeometric position no later than 2.0seconds from the time of measurementof the position to the time of transmission.

(2) Within the 2.0 total latencyallocation, a maximum of 0.6 secondscan be uncompensated latency. Theaircraft must compensate for any latencyabove 0.6 seconds up to the maximum2.0 seconds total by extrapolating thegeometric position to the time of message transmission.

(3) The aircraft must transmit itsposition and velocity at least once persecond while airborne or while movingon the airport surface.

(4) The aircraft must transmit itsposition at least once every 5 secondswhile stationary on the airport surface.

(f) Equipment with an approved deviation. Operators with equipmentinstalled with an approved deviationunder § 21.618 of this chapter also arein compliance with this section.

(g) Incorporation by Reference. Thestandards required in this section areincorporated by reference with theapproval of the Director of the Office of the Federal Register under 5 U.S.C.552(a) and 1 CFR part 51. All approvedmaterials are available for inspection atthe FAA’s Office of Rulemaking (ARM–1), 800 Independence Avenue, SW.,Washington, DC 20590 (telephone 202–267–9677), or at the National Archivesand Records Administration (NARA).For information on the availability of this material at NARA, call 202–741–6030, or go to http://www.archives.gov/

federal _ register/code _ of _ federal _regulations/ibr _ locations.html. Thismaterial is also available from thesources indicated in paragraphs (g)(1)and (g)(2) of this section.

(1) Copies of Technical StandardOrder (TSO)–C166b, Extended SquitterAutomatic Dependent Surveillance–Broadcast (ADS–B) and TrafficInformation Service–Broadcast (TIS–B)Equipment Operating on the RadioFrequency of 1090 Megahertz (MHz)(December 2, 2009) and TSO–C154c,Universal Access Transceiver (UAT)Automatic Dependent Surveillance–Broadcast (ADS–B) Equipment

Operating on the Frequency of 978 MHz(December 2, 2009) may be obtained

from the U.S. Department of Transportation, Subsequent DistributionOffice, DOT Warehouse M30, ArdmoreEast Business Center, 3341 Q 75thAvenue, Landover, MD 20785;telephone (301) 322–5377. Copies of TSO –C166B and TSO–C154c are alsoavailable on the FAA’s Web site, athttp://www.faa.gov/aircraft/air _ cert/ design _ approvals/tso/. Select the link‘‘

Search Technical Standard Orders.’’

(2) Copies of Section 2, EquipmentPerformance Requirements and TestProcedures, of RTCA DO–260B,Minimum Operational PerformanceStandards for 1090 MHz ExtendedSquitter Automatic DependentSurveillance-Broadcast (ADS–B) andTraffic Information Services-Broadcast(TIS–B), December 2, 2009 (referencedin TSO–C166b) and Section 2,Equipment Performance Requirementsand Test Procedures, of RTCA DO–282B, Minimum OperationalPerformance Standards for UniversalAccess Transceiver (UAT) AutomaticDependent Surveillance-Broadcast(ADS–B), December 2, 2009 (referencedin TSO C–154c) may be obtained fromRTCA, Inc., 1828 L Street, NW., Suite805, Washington, DC 20036–5133,telephone 202–833–9339. Copies of RTCA DO–260B and RTCA DO–282Bare also available on RTCA Inc.’s Website, at http://www.rtca.org/onlinecart/ allproducts.cfm.

9. Amend appendix D to part 91 byrevising section 1 introductory text toread as follows:

APPENDIX D TO PART 91—AIRPORTS/LOCATIONS: SPECIALOPERATING RESTRICTIONS

Section 1. Locations at which therequirements of §91.215(b)(2) and§ 91.225(d)(2) apply. The requirements of §§ 91.215(b)(2) and 91.225(d)(2) apply below10,000 feet above the surface within a 30-nautical-mile radius of each location in thefollowing list.* * * * *

Issued in Washington, DC, on May 21,2010.J. Randolph Babbitt,Administrator.

[FR Doc. 2010–12645 Filed 5–27–10; 8:45 am]BILLING CODE 4910–13–P

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