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Aircraft Certification and Production Standards
Aircraft Certification Requirements
Aircraft certifications requirements are derived from ICAO Annex 8 ‘Airworthiness of Aircraft’ and ICAO Doc. 9760 “Airworthiness Manual” Volume II ‘Design Certification and Continuing Airworthiness”. Each contracting state then establishes its own applicable regulations to implement internationally agreed standards and recommended practices.
Comparison of US and EU Regulations
In the USA and EU, procedures for certification of aeronautical products and the related organisational approvals are published in FAR Part 21 and EC Regulation 748/2012 respectively. In addition to these procedures, the requirements/specifications for certification of each category of products are published in different regulations and certification specifications.
The fundamental difference between the USA and EU system in this regard is that Certification Specifications published by EASA are non-binding technical standards. However, compliance with CS is a necessary condition for obtaining the relevant regulatory approval or certification. CS material may therefore be regarded as binding when taken in conjunction with the binding rules which require compliance with the CS. EASA Certification Memoranda provide another perspective on this matter.
The following list shows a list of airworthiness standards (US) and certifications specifications (EU) applicable to different categories of aircraft.
|Electronic Code of Federal Regulations||EASA Certification Specification|
|FAR Part||Title||EASA CS||Title|
|CS-22||Sailplanes and Powered Sailplanes|
|23||AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES||CS-23||Normal, Utility, Aerobatic and Commuter Aeroplanes|
|25||AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES||CS-25||Large Aeroplanes|
|27||AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT||CS-27||Small Rotorcraft|
|29||AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT||CS-29||Large Rotorcraft|
|31||AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS||CS-31GB CS-31HB||(Gas Balloons) (Hot Air Balloons)|
|33||AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES||CS-E||Engines|
|35||AIRWORTHINESS STANDARDS: PROPELLERS||CS-P||Propellers|
|CS-LSA||Light Sport Aeroplanes|
|CS-VLA||Very Light Aeroplanes|
|CS-VLR||Very Light Rotorcraft|
Acceptable Level of Safety
As part of the type certifications process, particularly for transport category aeroplanes, manufacturers need to demonstrate how they meet the acceptable level of safety defined in Part 25 and CS 25. Such specifications also makes reference to ARP4761 "Guidelines & Methods for Conducting Safety Assessment Process on Civil Airborne Systems and Equipment", which details the methodologies to be used such as:
- Functional Hazard Assessment,
- Fault Tree Analysis,
- Failures Modes and Effects Analysis,
- Common Cause Analysis,
- Zonal Safety Analysis,
- Particular Risk Analysis and
- Common Mode Analysis.
Unfortunately there are number of accidents that could have been prevented by more effective use of these methodologies.
Quality Management System
In addition to the robust design processes and compliance with the regulations to demonstrate acceptable level of safety, the TC holder must have effective quality management systems in place, particularly in order to ensure that the parts received from supply chain meets the required standards. For this reason International Aerospace Quality Group has created the AS/EN 9100 family ‘Quality Management System Standards for Aerospace Industry’. Since their introduction in 1999, they have been continually developed and revised and, currently, specific standards are published for manufacturing organisations (AS/EN9101), maintenance organisations (AS/EN 9111), part suppliers (AS/EN9121) etc.
Accidents and Incidents
The following events for which reports held on SKYbrary cite an OEM design fault as a contributory factor:
- B788, Boston MA USA, 2013 (On 7 January 2013, a battery fire on a Japan Air Lines Boeing 787-8 began almost immediately after passengers and crew had left the aircraft after its arrival at Boston on a scheduled passenger flight from Tokyo Narita. The primary structure of the aircraft was undamaged. Investigation found that an internal short circuit within a cell of the APU lithium-ion battery had led to uncontained thermal runaway in the battery leading to the release of smoke and fire. The origin of the malfunction was attributed to system design deficiency and the failure of the type certification process to detect this.)
- A321, en-route, near Pamplona Spain, 2014 (On 5 November 2014, the crew of an Airbus A321 temporarily lost control of their aircraft in the cruise and were unable to regain it until 4000 feet of altitude had been lost. An investigation into the causes is continuing but it is already known that blockage of more than one AOA probe resulted in unwanted activation of high AOA protection which could not be stopped by normal sidestick inputs until two of the three ADRs had been intentionally deactivated in order to put the flight control system into Alternate Law.)
- A306, vicinity Nagoya Japan, 1994 (On 26 April 1994, the crew of an Airbus A300-600 lost control of their aircraft on final approach to Nagoya and the aircraft crashed within the airport perimeter. The Investigation found that an inadvertent mode selection error had triggered control difficulties which had been ultimately founded on an apparent lack understanding by both pilots of the full nature of the interaction between the systems controlling thrust and pitch on the aircraft type which were not typical of most other contemporary types. It was also concluded that the Captain's delay in taking control from the First Officer had exacerbated the situation.)
- A332, en-route, Atlantic Ocean, 2009 (On 1 June 2009, an Airbus A330-200 being operated by Air France on a scheduled passenger flight from Rio de Janeiro to Paris CDG as AF447 exited controlled flight and crashed into the sea with the loss of the aircraft and all 228 occupants. It was found that the loss of control followed an inappropriate response by the flight crew to a transient loss of airspeed indications in the cruise which resulted from the vulnerability of the pitot heads to ice crystal icing.)
- CRJ2, en-route, east of Barcelona Spain, 2006 (On 27 July 2006, a Bombardier CRJ200 being operated by Air Nostrum on a scheduled passenger flight from Barcelona to Basel, Switzerland in night VMC, suffered a sudden left hand engine failure and an associated engine fire when passing FL235 some 14 minutes after take off. An air turn back was made with indications of engine fire continuing until just three minutes before landing. An evacuation using the right hand exits was ordered by the Captain as soon as the aircraft had come to a stop and had been promptly actioned with the RFFS in attendance. There were no injuries to the 48 occupants during the evacuation and the only damage was to the affected engine.)
- MD11, en-route, Atlantic Ocean near Halifax Canada, 1998 (On 2 September 1998, an MD-11 aircraft belonging to Swissair, crashed into the sea off Nova Scotia following an in-flight electrical fire.)
- A333, en-route, south of Moscow Russia, 2010 (On 22 December 2010, a Finnair Airbus A330-300 inbound to Helsinki and cruising in very cold air at an altitude of 11,600 metres lost cabin pressurisation in cruise flight and completed an emergency descent before continuing the originally intended flight at a lower level. The subsequent Investigation was carried out together with that into a similar occurrence to another Finnair A330 which had occurred 11 days earlier. It was found that in both incidents, both engine bleed air systems had failed to function normally because of a design fault which had allowed water within their pressure transducers to freeze.)
- MD82, Madrid Barajas Spain, 2008 (On 20 August 2008, an MD82 aircraft operated by Spanair took off from Madrid Barajas Airport with flaps and slats retracted; the incorrect configuration resulted in loss of control, collision with the ground, and the destruction of the aircraft.)
- E145, New York JFK USA, 2007 (On 17 December 2007, an Embraer 145 being operated by Chautauqua Airlines on a Delta Connection passenger flight departing New York JFK runway 31L for an unrecorded destination carried out a high speed rejected take off in normal day visibility when the response to elevator control input at rotation was abnormal.)
- A139, vicinity Sky Shuttle Heliport Hong Kong China, 2010 (On 3 July 2010, an AW 139 helicopter was climbing through 350 feet over water two minutes after take off when the tail rotor fell off. A transition to autorotation was accomplished and a controlled ditching followed. All on board were rescued, some sustained minor injuries. The failure was attributed entirely to manufacturing defects but no action was taken until two similar accidents had occurred in Qatar (non-fatal) and Brazil (fatal) the following year and two Safety Recommendations had been issued from this Investigation after which a comprehensive review of the manufacturing process resulted in numerous changes monitored by EASA.)
- A346, en-route, Amsterdam Netherlands, 2005 (On 8 February 2005, a Virgin Atlantic Airways A340-600 experienced in-flight fuel management problem which led to loss of power of No 1 engine and temporary power loss of No 4. The captain decided to divert to Amsterdam where the aircraft landed safely on three engines.)
- A319, en-route, Nantes France, 2006 (On 15 September 2006, an Easyjet Airbus A319, despatched under MEL provision with one engine generator inoperative and the corresponding electrical power supplied by the Auxiliary Power Unit generator, suffered a further en route electrical failure which included power loss to all COM radio equipment which could not then be re-instated. The flight was completed as flight planned using the remaining flight instruments with the one remaining transponder selected to the standard emergency code. The incident began near Nantes, France.)
- … further results