an introductionto airwothiness&...

An introduction to

Airwothiness & Type Certification

Giovanni Di Antonio 2017Pag. 1

Airwothiness & Type Certification

Eng. Giovanni Di Antonio

The information contained in this presentation is intended for educational purpose only, it exclusively refect the Author’s ideas and point of view and in some parts may not be completely updated. The content of this presentation has not been formally endorsed neither by the Italian Civil Aviation

Authority (ENAC) nor by the European Aviation Agency (EASA) or other Civil Aviation Authorities. Any implementation of the approaches and methodologies exposed in ths presentation remains under the complete responsibility of the implementer.

Rome, 20 Sep. 2017

SUMMARY

What we are talking about?

• Aviation safety

• Regulatory Framework and Civil Aviation Authorities


• Why we need Type Certification?

• Airworthiness Standards

• Type Certification Process

Introduction

What we will talk about?

Pag. 3

What we will talk about?

Regulations

Standards

a/c

Aerodr.

SAFETY APPROACH IN AVIATION

Safety is assured by imposing Tech. Req.s & Procedures to the Aviation System


Certificati

Oversight

Safety(occuants)

Org.

Pers.Source: Internet

Environ-ment

Man

SAFETY FACTORS


Man

Machine

Safety

Environ-ment

Man

SAFETY FACTORS


Man

Machine

Safety

AIRWORTHINESS

WHAT WE ARE TALKING ABOUT?

Airworthiness

Possession of the necessary requirements for flying in safeconditions within allowable limits


(ENAC Technical Regulation)

Requirements

Safety

WHAT WE ARE TALKING ABOUT?

Source: Internet


SafetyAirworth.

AllowableLimits

THE MACHINE

Aeronautical Product

AircraftEnginePropeller

Source: Internet


Aircraft (ICAO definition)Any machine that can derive support in the atmosphere from the reactions of

the air other than the reactions of the air against the earth’s surface

AIRCRAFT CLASSIFICATION (ICAO ANNEX 7)


Source: ICAO Annex 7

Part 1

Aviation safey

Pag. 11

Aviation safey

STATISTICS

Accident Summary by Type of Operation Worldwide Commercial Jet Fleet | 1959 – 2015


Tot: 1918 accidents

STATISTICS

Departures, Flight Hours, and Jet Airplanes in Serv ice Worldwide Operations Commercial Jet Airplanes (MTOM > 27216 kg)

Accident Rate = 1918 / 1321E+6 FH = 1.45 E-6 / FH


1321 mililon FH

STATISTICS

ICAO Accident Records 2011-2015Sheduled Commercial Flights (MTOM > 5700 kg)


Total number of accident = 503

Total number of flight hours (estimated) = 272 E+6 FH

Accident Rate = 503 / 272E+6 = 1.85 E-6 /FH

[Source: ICAO Safety Report 2016]

STATISTICS

Accident Rates and Onboard Fatalities by YearWorldwide Commercial Jet Fleet | 1959 - 2015


STATISTICS

Fatal Accidents and Onboard Fatalities by Phase of Flight Worldwide Commercial Jet Fleet | 2006 - 2015


STATISTICS

Fatalities by Aviation Occurrence CategoriesWorldwide Commercial Jet Fleet | 2006 - 2015

[TO BE NOTICED]

Only 10% of accidents is due to technical causes related to

system failures


THE CONCEPT OF SAFETY

Safety and Probability• Air navigation must be «safe» … what does it means? … how much?• Let us consider a generic “unwanted harmful events”

• To the machine• To people (occupants or third parties on the ground or in the air)• To properties & goods

• The probability that such an event occurs must be sufficently low


Source: CS-25 Book 2, AMC 25.1309

how low is

low enough?

THE CONCEPT OF SAFETY

Safety objectives : How to define acceptable level of probabilties?Let us consider a catastophic (CAT) event of a large aircraft

E = “a CAT event occurs”T = “the event is due to techincal causes (system failure)”T|E = “CAT event is due to technical causes (CAT failure)”Fi (i=1, …, n) = technical failures that lead to CAT event (n = 100, assumption)

P(E) = 1E-6/ FH (accident rate from the statistics)P(T|E) = 1E-1 (from the statistics)


P(T|E) = 1E-1 (from the statistics)p = P(Fi) = max allowed prob. (per FH) for system CAT failure (SAFETY TARGET)

We must have :P(E ∧ T) = P(E)*P(T|E) == P(F1 ∨… ∨ F100) = (small prob.) == P(F1)+ …+P(F100) = p + ... + p = 100*p

� (1E-6)(1E-1) = 100*p � p = 1E-9 / FH

Part 2

The Regulatory Framework and the

Pag. 20

The Regulatory Framework and the Civil Aviation Autorities

REGUALTORY AND LEGAL FRAMEWORKS

ChicagoConvention

(ICAO)

National Regulation

(EU Members)

Three regulatory frameworks: ICAO–EU–NATIONAL


EU Regulation(EASA)

OBBLIGATIONS

THE INTERNATIONAL FRAMEWORK

Convention on International Civil Aviation (Chicago, 1944)

– The Chicago Convention regulates the international civil aviation– Establishes the ICAO


[Source: Internet]

ICAO – International Civil Aviation Organisation

• UN specialised Agency established by the ChicagoConvention in 1944

• It regulates and controls the international civil aviation

• It regulates and oversighs the international civil aviationto the aim of harmoniziation

• It assures the uniform adoption of the provisionscontained in the Annexes to the Chicago Convention


contained in the Annexes to the Chicago Convention (SARPs – Standards and Recommended Practices)

• It promotes the safe development of the international civilaviation in a context of reciprocity and fair competition

ICAO only drafts policy when there was a high degree of maturity and

experience within one or several of its member States

ICAO ANNEXES

Chicago Convention Under the Art 37 each Contracting State must adopt and implement the standards contained in the ICAO Annexes

ICAO Annexes

Contains minimum safety objectives in terms of– Standards (mandatory) &


– Standards (mandatory) &– Recommendend Practices (optional)

� «SARP»

>>Up to now: 10000 SARPs of which 5000 related to groundinfrastructures

ICAO ANNEXES

• Annex 1 Personnel Licensing

• Annex 2 Rules of the Air

• Annex 3 Meteorological Service for International Air Navigation

• Annex 4 Aeronautical Charts

• Annex 5 Units of Measurement to be Used in Air and GroundOperations


Operations

• Annex 6 Operation of Aircraft

• Annex 7 Aircraft Nationality and Registration Marks

• Annex 8 Airworthiness of Aircraft

High level techical safetyrequirements

ICAO ANNEXES

• Annex 9 Facilitation

• Annex 10 Aeronautical Telecommunications

• Annex 11 Air Traffic Services

• Annex 12 Search and Rescue

• Annex 13 Aircraft Accident and Incident Investigation

• Annex 14 Aerodromes


• Annex 14 Aerodromes

• Annex 15 Aeronautical Information Services

• Annex 16 Environmental Protection

• Annex 17 Security: Safeguarding InternationalCivil Aviation Against Acts of Unlawful Interference

• Annex 18 The Safe Transport of Dangerous Goods by Air

• Annex 19 Safety Management

Annex 16

Volume I(Noise)

Volume II(Fuel Venting & Emissions)

STANDARD AND RECOMMENDED PRACTICIES (SARPs)

• Standard

• “Any specification for� Physical characteristics� Configuration� Material� Performance� Personnel� or Procedure

• the uniform application of which

• Recommended Practices

• “Any specification for� Physical characteristics� Configuration� Material� Performance� Personnel� or Procedure

• the uniform application of which


• the uniform application of whichis recognized as necessary forthe safety or regularity ofinternational air navigation

• and to which Contracting Stateswill conform in accordance withthe Convention;

• in the event of impossibility ofcompliance, notification to theCouncil is compulsory underArticle 38 of the Convention”

• the uniform application of whichis recognized as desirable inthe interest of safety, regularityor efficiency of international airnavigation

• and to which Contracting Stateswill endeavour to conform inaccordance with the Convention.

• States are invited to inform theCouncil of non-compliance.”

ICAO ANNEX 8

Annex 8

Definitions

Procedures

TypeCertificate

Production

Certificate ofAirworthiness

ContinuingAirworthiness


TecnicalReq.s

SmallAircraft

750 kg < MTOM ≤ 5700 kg

LargeAircraft

MTOM > 5700 kg

Helicopters

Engines& Propellers MTOM = Maximum Take-Off Mass

ICAO ANNEX 8

ICAO Annex 8 – Scope

• In the interest of safety (of occupants, other airc raft, third parties and property) , an aircraft must be designed, constructed and operated in compliance with the appropriate airworthiness requirements of the State of Registry of the aircraft

• The aircraft is issued with a Certificate of Airworthiness declaring it is fit to fly

• ICAO Standards would not replace national regulatio ns and codes of


• ICAO Standards would not replace national regulatio ns and codes of airworthiness containing the full scope and extent of detail considered necessary for the certification

• Each State is free to develop its own detailed code of airworthiness or to adopt those established by another Contracting State

• The State of Registry can recognize an airworthiness certificate issued by another Contracting State, if the airworthiness requirements under which such a certificate is issued are equal to or above the minimum standards contain ed in Annex 8

ICAO ANNEX 8

Anticipated operating conditions

• Environment in which an aircraft is expected to perform known from experience, reasonably envisaged to occur during the operational life of the aircraft

• Take into account the operations for which the aircraft is made eligible(Weather, terrain surrounding the aerodromes, functioning of the aircraft, efficiency of personnel, …)


personnel, …)

• Do not include extremes

– which can be effectively avoided by operating procedures

– which occur so infrequently that higher levels of airworthiness to meet them would render aircraft operations impracticable

ICAO ANNEX 8

Minimum (objective) technical requirements

Performance & Flying qualities

Structural Design & Construction

Engine & Propeller Design and Installation

Systems & Equipment Design and Installation


Systems & Equipment Design and Installation

Operating Limitations & Information

Crashworthiness & Cabin safety

Operating Environment and Human Factors

Security

EU REGULATORY FRAMEWORK

Implementing Rules for Type Certification

Reg. (EU) 748/2012 – Annex I (Part 21)


Source: www.easa.europa.eu


Regulation (EU) 216/2008

(Basic Regulation – BR)

“on common rules in the field of civil aviation and establishing a

European Aviation Safety Agency”

- It establishes the EU regulatory framework for aviation

- It establishes the European Safety Agency (EASA)


- It defines the Essential Requirements

The BR calls up the Chicago Convention

“The Chicago Convention (…) provides for minimum standards to ensure the safety of civil

aviation and environmental protection”

“Community essential requirements and rules adopted for their implementation should

ensure that Member States fulfil the obligations created by the Chicago Convention”


Basic Regulation Scope

Art. 2

Main scope“To establish and maintain a high uniform level of civil aviation safety in Europe”

Some other scopes


Some other scopes

“To promote cost-efficiency in the regulatory and certification processes and to

avoid duplication at national and European level”

“To assist Member States in fulfilling their obligations under the Chicago

Convention, by providing a basis for a common interpretation and uniform

implementation of its provisions, and by ensuring that its provisions are duly taken

into account in this Regulation and in the rules drawn up for its implementation”

ESSENTIAL REQUIREMENTS

Essential Requirements

(Annex I - Basic Regualation)

• Performance based high level safety requiremens in compiance with

ICAO Annexes

“Community essential requirements and rules adopted for their implementation should


Products … shall comply with the environmental

protection requirements (Art. 6 BR)



EssentialRequirement

(ER)

ER forairworthiness

ER forenvironmental

protection

Aircraft … shall comply with the essential

requirements for airworthiness (Art. 5 BR)

EASA

European Aviation Safety Agency (EASA)

• Estabished by Reg. (EU) 1592/2002 (repealed by Reg. (EU) 261/2008)

• On behalf of the Member States, it assumes its obligations arising frominternational and bilateral treaties


• It issues the technical saftey regulation (airwhorthiness standards) accordingto the ICAO Annexes along with the relevat interpretative material• CS – Certification Specifications• AMC & GM – Acceptable Means of Compliance and Guidance Material

• It certifies• Products (i.e. aircaft, engines and propellers)• Parts and Appliances• Design Organizations

EASA

EASA tasks

Art. 20 Basic Regulation

1. The Agency shall, where applicable and as specified in the Chicago

Convention or its Annexes, carry out on behalf of Member States the

functions and tasks of the state of design, manufacture or registry

when related to design approval –


(a) establish and notify the type-certification basis

(b) establish and notify the specific airworthiness specifications

(e) conduct, itself or through national aviation authorities or

qualified entities, investigations associated with products, parts

and appliances certification

(f) issue the appropriate type-certificates

EASA

2. With regard to organisations, the Agency shall:

(a) conduct, itself or through national aviation authorities or qualified

entities, inspections and audits of the organisations it certifies

(b) issue and renew the certificates of:


(i) design organisations

(ii) production organisations located within the territory of the

Member States, if requested by the Member State concerned

(iii) production and maintenance organisations located outside

the territory of the Member States

Part 3

Why we need Type Ceritification?

Pag. 39

Why we need Type Ceritification?EU Regulation (part 21)

TYPE CERTIFICATION SUMMARY

Type Cerification (at a glance)

• An aircarft can be admitted to the international naviation if it holds a valid

Certificate of Airworthiness (CoA)

• To have a CoA it must demonstrate that


• To have a CoA it must demonstrate that

� The single a/c conforms to an approved Type Design , and

� It must have no unsafe characteristics in relation to operations for which

it is approved

• A Type Design is approved when a Type Certificate is issued

TYPE CERTIFICATION SUMMARY

• A Type Certificate can be issued when it has been verified that the Type

Design (TD) complies with its Certification Basis (CB)

• The Certification Basis is built with the requirements issued by the

EASA in compliance with the Essential Requirements of the Basic

Regulation and, hence, in compliance with ICAO Annex 8 and Annex


Regulation and, hence, in compliance with ICAO Annex 8 and Annex

16. The CB also includes the Operational Suitability Data (OSD)

• The Type Certification process essentially consists on the definition of

the CB of the relevant TD and then in the verification that the TD

complies with the CB’s requirements

TYPE CERTIFICATION LEGAL BASIS

Based on the Chicago Convention

Art. 31 – Every aircraft engaged in international navigation shall be provided with a certificate of airworthiness issued or rendered valid by the State in which it is registered.

Art 37 – Each contracting State undertakes to collaborate in securing the highest practicable degree of uniformity in regulations, standards, procedures, and organization in relation to aircraft, personnel, airways and


procedures, and organization in relation to aircraft, personnel, airways and auxiliary services in all matters in which such uniformity will facilitate and improve air navigation. To this end ICAO shall adopt and amend (…) international SARPSs and procedures

� Each Contracting State is expected followthe ICAO Annexes


What does ICAO Annex 8 say about the CoA ?

– The Contracting State shall develop for each class of aircaft an airwothiness standard such that the compliance with the design requirements contaniend therein assures that the minimun safetyrequirements of Annex 8 are met (Part II Para. 1.2 )

– The Type Certificate is issued based on the evidence that the Type


– The Type Certificate is issued based on the evidence that the TypeDesign conforms to the design requirements of the applicableairworthiness code as specified in its CB (Part II Para. 1.4 )

– The Contracting State issues a Certificate of Airworthiness to an aircraft based on the evidence that the specific aircraft conforms to the design requirements of the applicable airworthiness standard (Part II Para. 3.2)


So, a CoA is issued …

based on the evidence that the specific aircraftconforms to the design req.s of the related aiworthiness

standard …

Yes, but how ?


Yes, but how ?

By verifing the conformity of the specific a/c to the approved Type Desing

Hence we have to understand what is a Type Design

EU REGULATION (PART 21)

Type Design

It is a complet set of information necessary to unambigously identify the

configuration and the design characteristics of an aeronautical

product in order to be able to assure conformity by comparison

21.A.31


(a) The type design shall consist of:

1. the drawings and specifications, and a listing of those drawings and specifications, necessary to

define the configuration and the design features of the product shown to comply with the applicable

type-certification basis and environmental protection requirements;

2. information on materials and processes and on methods of manufacture and assembly of the

product necessary to ensure the conformity of the product;

3. an approved airworthiness limitations section of the instructions for continued airworthiness as

defined by the applicable airworthiness code; and

4. any other data necessary to allow by comparison, the determination of the airworthiness, the

characteristics of noise, fuel venting, and exhaust emissions (where applicable) of later products of

the same type.

(b) Each type design shall be adequately identified.


Type Certificate

• It attests that a Type Design of an aeronautical product conforms

to the requirements of the established Certification Basis and

hence to the applicable airworhines standards, environemntal


requirements and to operational suitability data

• It also attests that the Type Design has no unsafe characteristics

in relation to the intended operations


A Type Certificate can be issued when

21.A.21

• The product to be certificated meets the applicable type-certification basis

and environmental protection

• Any airworthiness provisions not complied with are compensated for by

factors that provide an equivalent level of safety


factors that provide an equivalent level of safety

• No feature or characteristic makes it unsafe for the uses for which

certification is requested

• The engine or propeller have a type-certificate issued

• OSD data meets the applicable OSD certification basis

Basic Regulation Art. 5

2. (a) (…) The type-certificate (…) shall be issued when the applicant has shown that the product complies with a type-

certification basis (…) established to ensure compliance with the essential requirements (…) and when it has no

feature or characteristic making it unsafe for operation. The type-certificate shall cover the product, including all parts

and appliances fitted thereon

OSD=Operational Syuitability Data


Information and data associated to a Type Certificate

21.A.41

• Type Design

• Operating Limitations

• Type Certificate Data Sheet (TCDS) for airworthiness and emissions

• Type Certification Basis and Environmental Protection requirements


• Type Certification Basis and Environmental Protection requirements

• Any other conditions or limitations prescribed for the product

• Operational Suitability Data (OSD) and OSD certification basis

• TCDS for noise

• Record of emission compliance (for Engines)


Restricted Type Certificate (RTC) 21.A.23

It is issued to a Type Design which does not comply with the Airwortinesss CB as defined in 21.A.21(c) if it is shown that

– Appropriate type-certification basis established by the Agency ensuring adequate safety with regard to the intended use of the a/c


ensuring adequate safety with regard to the intended use of the a/c

– Applicable environmental protection requirements

– Applicable operational suitability data certification basis designated in accordance with point 21.A.17B

CB= Certification BasisAW=Airworthinessa/c=Aircaft


Supplemental Type Certificate (STC) Part 21 Subpart E

• It is an approval of a major modification to a Type Design, designed by an Applicant who is not the product’s TCH

• A major modification to a part affected by an STC is a new STC


• A major modification to a part affected by an STC is a new STC

• Only the STCH can design a major modification to its STC

• In general the STCH has to hold a DOA or an APDOA

TCH=Type Certificate HolderSTCH=Supplemental Type Certificate HolderDOA=Design Organization ApprovalAPDOA=Alternative Procedure DOA


European Technical Standard Order (ETSO )Part 21 Subpart O

• Technical Specificatios of Parts & Appliances to be installed onboard the a/c• The ETSO approval includes both design and production aspects• Declaration of Design and Perfomance (DDP): functional performences,

environmental limitation, qualification tests passed, maintenance to be carriedout, declaration of compliance to a specific CS-ETSO


Parts’ Ceritfication

ETSO DDP must be adequate

within a TC

Qualification & Compiance


Certificate of Airworthiness• Attests the conformity of an a/c to the approved Type Design

• Attests the continued airworhiness of the product

Enable the a/c to the national and intenational air navigation

(Art. 764 Code of Navigation)

(Art. 31 Chicago Convention)


(Art. 31 Chicago Convention)

Basic Regulation Art. 5

2.(c) each aircraft shall be issued with an individual certificate of airworthiness when it is

shown that it conforms with the type design approved in its type-certificate and that

relevant documentation, inspections and tests demonstrate that the aircraft is in

condition for safe operation.


Continuing Airwothiness (CAW )

• An a/c holds in an airworthy state as long as it complies with the

ER (i.e. with its CB) and does not have any dangerous

characteristics in relation to its intended use

(fit -to-fly )


(fit -to-fly )• The CAW consists in all those procedures and maintenance or

corrective tasks which assure the a/c continues to hold in an

airworthy state

[Source: Internet]


AW

Initial AW Initial Type Certification

Maintenance ICA

Repair


CAW

Repair

TDModifications

Occurrences SB & ADAW = AirworthinessCAW=Continued AirworthinessTD=Type DesignICA=Istruction for Continued AirwothinessSB=Sevice BullettinsAD=Airwothiness Directive

Aging

Aircaft


Instructions for Continued Airworthiness (ICA )21.A.61

• Instructions necessary to carry out maintanace task i.a.w. theMaintenance Manual

• The TCH must produce, update and furnish a complete set of ICA toeach known owner of a product before its delivery or before issue ofthe first CoA whichever occurs later and then make the ICA available


the first CoA whichever occurs later and then make the ICA availableon request to any person required to comply with them

• Must be prepared in accordance with the CB req.s (CS XX.1529)

• Those ICAs dealing with overhaul or other forms of heavymaintenance, may be delayed until after the product has entered intoservice, but not after the products reaches the relevant age or flight-hours/cycles.


CS 25.1529 Instructions for Continued Airworthiness

Instructions for Continued Airworthiness inaccordance with Appendix H must be prepared.

ICA content (e.g. CS- 25 large a/c)


• a/c systems description, information and maintenance data• Checks and relevant procedures• Servicing• Sheduled maitenance tasks• Installation/Removal procedures• Troubleshooting

• Aiwothiness Limitation Section (ALS)


Airworthiness Limitation Section (ALS)H25.4 Airworthiness Limitations section

(a) The Instructions for ContinuedAirworthiness must contain a section titledAirworthiness Limitations that is segregated andclearly distinguishable from the rest of thedocument. This section must set forth –

(1) Each mandatory replacementtime, structural inspection interval, andrelated structural inspection procedureapproved under CS 25.571: and (:…)

ALS

Life Limited Parts(Replacement

Time) CS 25.571 (*)

DamageTolerance Data

CS 25.571 (*)

(*) In other airworthiness codes Fatige & DT req.s may be specified in different Para.s (e.g. CS 23.571, 572, 573, 575)


approved under CS 25.571: and (:…)

(3) Any mandatory replacement timeof EWIS components as defined in CS25.1701 (…)

(b) (…). This section must contain a legible statement in a prominent location that reads: ‘The Airworthiness Limitations Section is approved and variations must also be approved’.

EWIS(Replacement

Time) CS 25.1701

ALS is approved by EASA during Type Certificationand it is made mandatory by AD

EWIS – Electrical Wiring Interconnection System = any wire, wiring device, or combination of these, including termination devices, installed in any area of the aeroplanefor the purpose of transmitting electrical energy, including data and signals between two or more intended terminationpoints.


Airworthiness Directives (AD)21.A.2B

• Document issued or adopted by EASA which mandates actions to be performed on an aircraft to restore an acceptable level of safety

• An AD is issued when:– an unsafe condition (ref. 21.A.3C) exists in an a/c, as a result of a

deficiencyin the a/c, engine, propeller, part or appliance installed; AND


deficiencyin the a/c, engine, propeller, part or appliance installed; AND– that condition is likely to exist or develop in other a/c

• The TCH shall– propose the appropriate corrective action or required inspectionsand

submit details to EASA for approval

– make available descriptive data and accomplishment instructions to those who are concerned

TCH=Type Certificate Holder


Type Design Modification (or Changes)Part 21 Subpart D

Must comply with the applicable aiworthiness req.s

Minor Substantial New TC

21.A.91 21.A.19


Mod.

Minor

Major

Substantial New TC

SignificantCB updated to the latest Amdt at the time of Application

Not SignificantOriginal CB

(TCDS) or belowthe latest Amdt

Standard

21.A.101 21.A.90B TC=Type CertificateBdC=Base di Certificazione


Substantial Changes21.A.19

A change which is so extensive that a substantially complete investigation of compliance with the applicable type-certification basis is required, and consequently a new type certificate

CS 25 Exemples


CS 25 Exemples– Change in the number or location of engines– Change from a high wing to low wing– Change from an all metal aeroplane to all composite primary structure– Change of empennage configuration (cruciform vs. ‘T’ or ‘V’ tail)– Increase from subsonic to supersonic flight regime

�New TC / TCDS required TC=Type CertificateTCDS=Type Certificate Data Sheet


Minor Change21.A.91

• Do not have an «appreciableeffect» on- Mass & Balance- Structural strength- Reliability

Major Change21.A.91

• Non-Minor Modifications

• Only the TCH can apply for a Major Mod. approval


- Reliability- Operational characteristics- Noise, Fuel venting &

Exhaust emission- Operational Suitability Data - Other characteristics

affecting the airworthiness

• Any legal person can apply forMinor Mod. approval

• The TCH must hold a valid DOAor APDOA

TCH=Type Certificate HolderDOA=Design Organization ApprovalAPDOA=Alternative Procedure DOA


(Non Standard) Changes Classification ProcessGM 21.A.91



yes



Significant Changes21.A.101

It changes at the product level one or more of the following: 1) General configuration2) Principles of construction3) Assumptions used for certification

(but not to the extent to be considered a substantial change)

See ex. in Appendix A to GM 21.A.101


(but not to the extent to be considered a substantial change)

Must be considered in the context of all previous relevant design changes (ex. numerous slightly increments of MTOM)

CB impact: Must comply with the latest Amdt. of the rule, unle ss- it is impractical or - it does not contributes materially to the level of safety of the changed product

(little safety gain)


Standard Changes21.A.90B

• Aeroplanes MTOM ≤ 5 700 kg

• Rotorcraft MTOM ≤ 3 175 kg

• ELA1 & ELA 2 (powered) sailplanes, balloons and airships


• ELA1 & ELA 2 (powered) sailplanes, balloons and airships

• Must comply with design data included in specific CS – acceptable methods– techniques and practices– ICA

ELA = European Light Aircraft (Rif. Art 1 Reg. (EU) 748/2012 as amended)ELA1 includes: non complex motor-powered aeroplane, Sailplane of MTOM ≤1200 kgELA2 includes: non complex motor-powered aeroplane, Sailplane MTOM ≤ 2000 kg, Very Light RotorcaftCS = Certification Specificatins issued by EASAICA = Istructions for Continued AirworthinessTCH = Type Certificate Holder


RepairsPart 21 Subart M

• Same classification of Modifications– Minor– Major– Standard


– Standard

• Must comply with the applicable airwothiness req.s

• Can be temporary

• The Applicant must hold a DOA or APDOA


Permit To Flight (PTF)Part 21 Subpart P

• For a/c’s that do not (fully) comply with the applicable aiworthinessreq.s even if they are able to safely flight under specifiedconditions and limitations

• Specific scopes


• Limited time duration

• For single a/c only

• Pre-approved Flight Conditions needed


PTF main

Develop-ment

Showingcompliance

with CS

DO/PO Crew

TrainingProduction

flight testing

Production Ferry Flight


mainscopes

Production sites transfer

Customeracceptance

Delivering/Export

Exibitions/ Air Show

Market survey/ Customer crew

training21.A.701


Application FC Approval(EASA/NAA)

ConformityInspection

(NAA)

PTF issuing(NAA)

PTF issuing processPart 21 Subpart P Config. as built = Config. as designed

+ accepted deviations


FC

Design Related

EASA Approval

Non Design Related

NAA Approval


Configuration

Conditions & Limitations


FC21.A.707

Safety of Flight

Demosntation

ConfigurationControl

Procedure


Cofiguration

Conditions & Limitations

itineraries or

airspace

Flight crew

carriage of persons

other than flight crew

operating limitations procedures

technical conditions


FC21.A.707

Safety of Flight

Demonstration

ConfgurationControl

Demonstration

Flight test program

(if applicable)

Maintenance

Part 4

Airworthiness Codes

Pag. 72

Airworthiness Codes

REGULATION & SAFETY

What is an airworhiness code?

Technical req.s imposed to Type Design to assure a certain level of saftey

Regulations impose


Regulations impose increasing levels of severity assuringincreasing levels of safety

[Source: Internet- EASA Presentation for Workshop GA 14 Nov. 2014]

REGULATION & SAFETY

The practicability criterion

• We have diferent classes of products

• The severity imposed by a regulation is increased up to the levelwhere the sacrifice (cost) to be payed for implementation isgrossly disproportinate w.r.t. safety gain


COST

SA

FE

TY IMPRACTICAL

ALARP concept(As Low As ReasonablyPracticabe)

AIRWORTHINESS STANDARDS

Main Certification Specifications (CS)

CS-VLA Very Light Aeroplanes

CS-VLR Very Light Rotorcrafts

CS-22 Sailplanes and Powered Sailplanes

CS-23 Normal, Utility, Aerobatic and Commuter Category Aeroplanes

CS-25 Large Aeroplanes


CS-27 Small Rotorcrafts

CS-29 Large Rotorcrafts

CS-34 Aircraft Engine Emissions and Fuel Venting

CS-36 Aircraft Noise

CS-E Engines

CS-P Propellers

AIRWORTHINESS STANDARDS’



• BOOK 1 – AIRWORTHINESS CODE

• SUBPART A – GENERAL

• SUBPART B – FLIGHT

• SUBPART C – STRENGTH REQUIREMENTS

• SUBPART D – DESIGN AND CONSTRUCTION

Disciplines


• SUBPART E – POWERPLANT

• SUBPART F – EQUIPMENT

• SUBPART G – OPERATING LIMITATIONS AND INFORMATION

• APPENDICES

• BOOK 2 – ACCEPTABLE MEANS OF COMPLIANCE (AMC)

Disciplines

How quantitative Req.s are defined?

Ex. Stall velocity limitation for CS-23, CS-VLA a/c’s

• CS-23 limits the stall speed (hence the flight speed) to 61 KT for a Single Engine Arcraft

• This req. limits the ground impact velocity and hence the impact KE in case of a minor crash landing due the engine failure (engine off)



case of a minor crash landing due the engine failure (engine off)

• CS-VLA limits the stall speed at lower (more conservative) value of 45 KT because it allows to intstall CS-22 less reliable engines which are expected to fail more often

The mean number of events inceases (engines fail more often) but the severity of each event deceases (the impact KE is lower) so that the risk

(hence the level of safety) remains the same in terms of expectedcasualties

CS 23.49 Stalling speed

(…)(c) Except as provided in sub-paragraph (d)of this paragraph, VSO at maximum weight must not exceed 113 km/h (61 knots) for –(1) Single-engined aeroplanes; and(2) Twin-engined aeroplanes of 2722 kg (6 000 lb) or less maximum weight that cannot meet the minimum rate of climb specified in CS 23.67 (a) (1) with the critical engine

CS 23.562 Emergency landing dynamic conditions

(…)(d)(1) The ultimate load factors of CS23.561(b) must be increased by multiplying the load factors by the square of the ratio of the increased stall speed to 113 km/h (61 knots). (…)



CS 23.67 (a) (1) with the critical engineinoperative.(d) All single-engined aeroplanes, and thosetwin-engined aeroplanes of 2722 kg (6 000 lb) or less maximum weight, with a VSO of more than 113 km/h (61 knots) at maximum weight that do not meet the requirements of CS 23.67(a)(1), must comply with CS 23.562(d)

UAS REQUIREMENTS

JARUS

Joint Authorities for Rulmaking

on Unmanned Aircfat Systems

(54 Member States)

JARUS CS-LURS – Rotary wing - MTOW<750 kg

[Source: Internet – JARUS Web Site]


JARUS CS-LUAS – Fixed wing - MTOW < 750 kg

JARUS CS-UAS – Every config. - MTOM < 750 kg –

performance based (under development)

UAS REQUIREMENTS

New safety philosophy

• UAS = UA + GCS (RPAS = RPA + RPS)

• No occupants onboard (…for the time being…)

• Third parties (on ground, in air, at sea) & critical infrastructures ’ safety

• May be complex irrespective to the MTOM

UAS = Unmanned Aircraft System (include sistemi autonomi)RPAS = Remote Piloted Aircfat SystemUA = Unmanned AircraftGCS = Ground control StationRPS = Remote Pilot StationC2 = Command and Control (data link)


• May be complex irrespective to the MTOM

• C2 Function ?

[Source: CS-LUAS Book 2]

UAS REQUIREMENTS

UAS Risk-Based classification


C - CERTIFIEDB - SPECIFICA - OPEN

[Source: JARUS]

UAS REQUIREMENTS

Some UAS req.s

• FCS envelope protection(CS LUAS/LURS.23, 1329)

• ERC (Emergency Recovery Capability)(CS LUAS/LURS.1412, .561)

[Source: CS-LUAS Book 2]


- Automatic pre-programmed procedure to reach a pre-definedumpopulated forced landing area

- FTS (Flight Termination System)

• RPS new «product» eligible for a TC (CS LUAS Subpart I)

FCS=Flight Control System

PERFORMANCE BASED REGULATION

The new CS/FAR 23 and CS-UASCS 23 Amdt 5 & JARUS CS-UAS

What we had ….[Source: Internet]


Gross differences : performances | complexity | tecno logy | operations[Source: EASA CS-25 Amdt 5 NPA]


Problems with traditional approach

• Relation between MTOM vs Complexity

• Very detailed (prescriptive) design-related req.s

• Not always aligned with technology development (UAS, composites, Complex HW & SW, glass cockpit…)

MT

OM

CS 25, CS 29


• Special Conditions needed (Slow and complex certification process)

• Innovation could not be promptly supported

• Req.s may be to demanding for low performance a/c

PERFORMANCE & COMPLEXITY

CS 23 Amdt 5


The solution (?)

High level performance based objectiverequiriments

The Applicant may developdetailed de to comply with the objective req.s

ADS – Aiworhiness Design Standards (EASA Approved)

ANNEX 8 ICAO


Standards (EASA Approved)

CS 23 Amdt. 4 is an approved ADS

DesignReq.

MOC ADS

[Source: EASA CS-25 Amdt 5 NPA]

Part 4

Type Certification Process

Pag. 87


DESIGN CAPABILITY

To apply for a TC the Applicant must shown its design capability

21.A.14

TCRTC

DOA Part 21 Subpart J


DOA =Design Organization Approval, AP-DOA = Alternative Procedure DOA , ELA = European Light Aircraft

ELA2ELA 2 Engine/Propeller

Piston EngineFixed or adjustable pitch propeller

APDOAAd hoc procedures linked to

specific projects

ELA1ELA 1 Engine/Propeller Certification Program

TYPE CERTIFICATION PROCEDURES

joint exercise

Applicant Certification Team&

EASA Certification Team


Does notintervene in the design phase


EASA Certification Team

Demonsnrates the compliance with the CB

req.s

Estabishes the CB and verifies that the Applicant has complied with the CB

req.s


Preliminar Phases

Application(Applicant)

EASA PCM designation

PCM=Project Certification ManagerPID=Progect Information DocumentToR=Terms of Reference


EASA CertificationTeam of Experts

(per discipline)

Project Information Document (PID)

(with the ToR)


Phase IPhase II

CertificationPhase III

Compliance

Phase IVFinal Report

Certification process : 4 phases


FamiliarizationCertification

ProgramCompliance

demonstration

Final Report and TC issuing


Phase IPhase II


Compliance



FAmiliarizationCertification

ProgramCompliance

demonstration


[Source: Internet]


Phase I

Technical Familiarisation and establishment of the

Type Certification Basis

- Certification Team gathers information on the


- Certification Team gathers information on the

projects

- Agreement of the Certification Basis

CRI A-1CRI = Certification Review Item


Certification Basis

It is the set of detailed technical requirements of Airworthiness,

Environmental Protection and Operational Suitability Data, which assure

that the Type Design complies with the Essential Requirements

Basic Regulation


Basic Regulation

Art. 20

1.(a) certification basis consists of the applicable airworthiness code, the provisions

for which an equivalent level of safety has been accepted and the special

detailed technical specifications necessary when the design features of a

particular product or the experience in operation render any of the

airworthiness code provisions inadequate or inappropriate to ensure

conformity with essential requirements

OSD=Operational Suitability Data


Certification Basis structure21.A.17A, 21.A.17B, 21.A.18

CERTIFICATION BASIS

AW Req.s21.A.17A

ODS Operational Suitability Data

21.A.17B

Environmental ProtectionReq.s

21.A.18


CS SC

ELOSArt 20(a) BR

FCD CCD

SIMD MCSD

MMEL SC

NoiseCS-36

Engine Emissions& Fuel Venting

CS-34

BR = Basic regulation

CS – Certification Specifications

SC = Special Conditions

ELOS – Equivalent Level Of Safety

FCD – Flight Crew Data

CCD – Cabin Crew Data

SIMD – Simulator Data

MCSD - Maintenance Certifyng Staff Data

MMEL – Master Minimum Equipment List


Operational Suitability Data (OSD)

21.A.23

• OSD are data important for the safety of operations

- Pilot training (FCD)- Maintenance staff qualification (MCSD)- Simulator qualification (SIM)- Master Minimum Equipment List (MMEL)


- Master Minimum Equipment List (MMEL)- Type specific data for cabin crew (CCD)

• Approved as an integral part of the TC

TC = AW + EP + OSD • Can be either mandatory or recommended

(NAA can mandate those recommended) NAA=National Aviation Authority


Special Conditions (SC)21.A.16B

• Ad hoc specific technical req.s set by the Agency when the applicable CS does not contain adequate AW standards for

- Novelties (w.r.t. the CS assumpions)


- Non conventional use

- Unsafe conditions (from experience or similar products)

• Must assure a level of safety equivalent to the applicable CS


Equivalent Level of Safety (ELOS)Art 20(1)(a) BR, 21.A.21(c)(2)

“Any airworthiness provisions not complied with are compensated for by factors that provide an equivalent level of safety”

DeviationsEASA MB Decision 12-2007 – Products Certification Procedures


EASA MB Decision 12-2007 – Products Certification Procedures

• Used in certification practice when some part of the design cannot comply with the applicable CS and such a deviation does not qualify for an ELOS

• In order for a product to be eligible for a standard TC, any deviation must ensure conformity with the essential requirements

• Otherwise, the aircraft would only be eligible for a restricted type certificate (RTC)


CS

Level of safety

ER

FULL CS COMPLIANCE

ELOS

OPERTIONAL CONDITIONS & LIMITATIONS

DEVIATIONS


Standard TC Restricted TC CS=Certification SpecificationsER=Essential RequirementsELOS=Equivalent Level Of Safety


Changed Product Certification BasisGM 21.A.101

“TOP DOWN APPROACH “


yes

yes


No



Phase IPhase II


Compliance



FamiliarizzazioneCertification

ProgramCompliance

demonstration



Phase II

Agreement of the Certification Programme

- Agreement on the Means of Compliance (MOC)

used for each CB Req


used for each CB Req

- Level of Involvement (LOI) of the Certification

Team


Certification Programme21.A.20(b), AMC to 21.A.20(b)

“The applicant shall provide the Agency with a certification programme detailing the means for compliance demonstration . This document shall be updated as necessary during the certification process.”


• Project and operations description• Means of Compliance (MOC)• Compliance Check List (CCL)• Identification of the personnel having a decision role on AW, OSD, EP • Planning

MOC=Menas of ComplaianceCCL=Complaicne Check ListAW=AirwothinessOSD=Operational Suitability DataEP=Environmental Protection


MOC



Compliance Check List (CCL)



Level of Involment (LoI)EASA Opinion No 07/2016


Source: EASA Presentation “EASA Level of Involment (LOI) project”, Oct. 2015


Phase IPhase II


Compliance

PhaseIVFinal Report



ProgramCompliance

demonstration

Final Report and TC issue

[Source: Internet]


Phase III

Compliance determination

- Demonstration & Verification (Applicant)


- Verification based on LoI (certification Team)


Phase IPhase II


Compliance




ProgramCompliance

demonstration



Phase IV

Final Report and issue of a Type Certificate

- Declaration of Compliance (Applicant)

- Statements of Satisfaction (Team Experts)


- Type Certification Board Meeting (Applicant &

Cert. Team)

- Final Report (PCM)

- Type Certificate issuing (EASA)

CM(Policy)

CRI


CM – Certification MemorandumCRI – Certification Review ItemCAI – Certification Action itemCM – Certification Memorandum


TypeCertification

Tools

CRI

CAI

CM(Policy)

CRI


BdCCRI A-1 MOC

ELOS / Deviations


CRI

CAI

TypeCertification

Tools

ControversialIssues

Thank youfor your attention

Pag. 114

for your attention

[email protected]

The information contained in this presentation is intended for educational purpose only, it exclusively refect the Author’s ideasand point of view and in some parts may not be completely updated. The content of this presentation has not been formallyendorsed neither by the Italian Civil Aviation Authority (ENAC) nor by the European Aviation Agency (EASA) or other Civil

Aviation Authorities. Any implementation of the approaches and methodologies exposed in ths presentation remains under the complete responsibility of the implementer.

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