operational procedures for laq - international civil aviation … · 2012. 8. 3. · icao...

ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007

Operational Procedures for LAQOperational Procedures for LAQ

John-Paul ClarkeAssociate Professor of Aerospace EngineeringDirector of the Air Transportation LaboratoryGeorgia Institute of Technology


OutlineOutline

1. Introduction2. Continuous Descent Arrival3. Surface Movement Optimization4. Conclusions


IntroductionIntroduction

Air transportation is: • Enabler of economic growth• Catalyst for economic development

Environmental impact of aviation is:• Significant concern at the global and local levels• Local air quality is a rapidly growing concern

Issue must be addressed in a comprehensive way• Reductions at source• Operational procedures*• Operational charges and restrictions


• Sequence and spacing achieved between top-of-descent and metering point(during descent from cruise a.k.a. initial portion of descent)

• No vectoring after passing metering point(during descent to runway a.k.a. latter portion of descent)

• Metering point dependent on traffic conditions

Hei

ght

ｴ

Monitoring/Intervention

Missed App.

Conventional

FAF

Wake VortexSeparation

4 - 6 nm

ｴ

Streaming/SequencingStreaming/Sequencing Monitoring/Intervention

Descent from CruiseDescent from Cruise Missed App.

Conventional

FAF

Wake VortexSeparation

4 - 6 nm

SpacingSpacing

Metering Point

Descent to Runway

Top-of-Descent

Continuous Descent Arrival (CDA)Continuous Descent Arrival (CDA)


CDA for 2004 SDF Flight TrialsCDA for 2004 SDF Flight Trials


LAQ, Noise, and Economic BenefitsLAQ, Noise, and Economic Benefits

Local emissions reduced• CO below 3,000 ft reduced by 12.7% (B-767) and 20.1% (B-757)• HC below 3,000 ft reduced by 11.0% (B-767) and 25.1% (B-757)• NOx below 3,000 ft reduced by 34.3% (B-767) and 34.4% (B-757)

Noise impact reduced• Lower per aircraft noise levels

(3 to 6 dBA; 7 to 15 NM from runway)• Impact concentrated in narrow corridors

Economic costs reduced• Fuel to fly last 180 nm to runway reduced by

364 lbs/flight (B-767) and 118 lbs/flight (B-757)• Time to fly last 180 nm to runway reduced by

147 seconds/flight (B-767) and 118 seconds/flight (B-757)


Challenge: Getting the “Right” SpacingChallenge: Getting the “Right” Spacing

Spacing (nm)

Prob

abili

ty D

ensi

ty

Target spacing at metering point

Required separation at runway

Range of spacing at runway for a given target spacing at metering point;

Shaded area equal to confidence that descent to runway can be completed without controller intervention;

Shape of distribution depends on target spacing.


Separation and Throughput

Analysis

Min. FinalSeparation

Max. FinalSeparation

Separation at Metering Point

Intermediate Metering Point Runway Threshold

Time

Along Track Distance

Trailing ACTrailing AC

Leading ACLeading AC

• Shaded area indicatestrajectory variation

• Final separation will be a probability distribution



Initial Positionof Trailing AC

Initial Positionof Leading AC


in Time

Min. FinalSeparation

Max. FinalSeparation


Intermediate Metering Point Runway Threshold

Time

Along Track Distance

Trailing ACTrailing AC

Leading ACLeading AC





Initial Positionof Trailing AC

Initial Positionof Leading AC


in Time


Prob

abili

ty D

ensi

ty

FeasibleSeparation, p1

AC Type A – Type BFeasible

Separation, p2AC Type B – Type A

A small slice of traffic at separation s

Actual TrafficUnadjusted, pT

Actual TrafficAdjusted, pTa

Target Separation SI


Prob

abili

ty D

ensi

ty

FeasibleSeparation, p1

AC Type A – Type BFeasible

Separation, p2AC Type B – Type A

A small slice of traffic at separation s

Actual TrafficUnadjusted, pT

Actual TrafficAdjusted, pTa

Target Separation SI

Trajectory

Fast-Time Aircraft

Simulator

Fast-Time Aircraft

Simulator

Con

volu

tion

Monte Carlo Tool

Procedure DefinitionAircraft / Flap Schedule

Weight Distribution

Pilot Response

Local Wind Variation

Wind Forecast

45/270, 4000030/256, 2000021/252, 900010/249, 450

Tool for the Analysis of Separation and Throughput (TASAT)Tool for the Analysis of Separation and Throughput (TASAT)


R&D Activities in AtlantaR&D Activities in Atlanta

Flight test of time-based arrival fix metering*• Demonstrate ability to set initial spacing based on aircraft type, weight, and wind,

and deliver aircraft on final approach with very high accuracy in terms of both time and spacing

• Began on 16 April 2007Time-based metering of arrivals from NE and NW destined to 8L/26R*

• Build upon results of 2007 flight test• Starting in 2008 or 2009

Metroplex design for 2015 and 2025• JPDO project to develop a concept of operations for 2015 and 2025 at ATL

* Partnership between Delta, Georgia Tech, FAA (HQ, ZTL, ZTL-A80)


CDA for 2007 ATL Flight TrialsCDA for 2007 ATL Flight Trials


Reduced Low Altitude VectoringReduced Low Altitude Vectoring


Surface Movement OptimizationSurface Movement Optimization

What’s wrong with this picture?


Growth Rates versus Phase of FlightGrowth Rates versus Phase of Flight


Airport & Terminal Area Traffic FlowAirport & Terminal Area Traffic Flow


Airport & Terminal Area QueuesAirport & Terminal Area Queues

Taxiway RampGatesDeparture

Runway (22R)Arrival Runways

27/22L

Arrival routes

Departure routes

Local Controller

Local Controller Ground Controller

Ground Controller

Gate ControllerControl actions

Resource utilization

FixesLanding queues

Exit fix queues

Takeoff queues

Departure runway crossing

queues

Arrival runway crossing queues

Departure taxi queues

Arrival taxi queues

Departure ramp queues

Ally blocked or gate occupied queues

Turnaround

Pushback queues


“ N Control”“ N Control”

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0 5 10 15 20 25 30

No. of Aircraft Taxiing Out

Take

off R

ate

(per

min

ute)

• Saturation point beyond which there is no significant gain in takeoff rate

• Gate release control may be used to provide the desired number of aircraft

• Meets objectives of• Maximizing throughput • Reducing engine-run times• Reducing fuel burn• Reducing emissions


Two-Stage Optimization AlgorithmTwo-Stage Optimization Algorithm


37.44

34.73

39.9238.74

20

25

30

35

40

45

50

Unrestricted Restricted

Traffic Scenario

Dep

artu

res

/ Hou

r

WITHOUT Planning

WITH Planning

40.98

48.89

55.351.4

15

25

35

45

55

65

75

85

Unrestricted RestrictedTraffic Scenario

Del

ay (M

in)

WITHOUT Planning

WITH Planning

decreased delayincreased throughput

Operational Benefits of OptimizationOperational Benefits of Optimization

FCFS with EWR & JFK

Miles In Trailactive

Runway Idle Time

EWR:35 MIT

JFK:30 MIT

Availability Seq.@ Rwy

(also FCFS withNO Active

Restrictions)

Time


LAQ Benefits of OptimizationLAQ Benefits of Optimization


ConclusionsConclusions

Operational procedures can provide (and are providing) much needed LAQ benefits:

• Well designed CDA’s significantly reduce (in many cases eliminate) low altitude vectoring and reduce the time in the mixing layer

• Surface movement optimization significantly reduces taxi time and thus the emissions from surface operations (fastest growing emissions segment)

Development of operational procedures will also provide solutions to some fundamental air traffic control questions:

• How does terminal area trajectory prediction accuracy vary as a function of uncertainties in wind, aircraft weight, pilot performance?

• 4-D trajectory management limits• Under what conditions can precise aircraft sequencing and spacing be achieved

in the terminal area and one the surface with “strategic control?”• Requirements for avionics, air traffic control decision support and wind prediction tools

operational procedures for laq - international civil aviation … · 2012. 8. 3. · icao...

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