October 7, 2009
What’s at Issue
The Federal Aviation Administration (FAA) will soon propose revisions to Advisory Circular (AC) 21.101-1.
Why It’s Important
Federal Aviation Regulation (FAR) 21.101, also known as the Changed Product Rule, requires an applicant for a change to a type certificate to meet the latest requirements, except where the change is not significant, where areas of the product are not affected, where it would be impractical, or where it would not contribute materially to the level of safety of the changed product. AC 21.101-1 provides guidance for establishing the certification basis for changed aeronautical projects and identifying the conditions under which it will be necessary to apply for a new type certificate. The FAA will soon propose revisions of this AC to harmonize with Transport Canada (TC) and the European Aviation Safety Agency (EASA) guidance. All three agencies are working together to revise the guidance.
Major Provisions
Scope
The AC applies to type certification during design but can also significantly impact aircraft modifications. Maintenance organizations performing avionics or interiors modifications will need to comply with the new AC.
Avionics Modifications
Two major changes could affect avionics modifications. First, adding new flight guidance devices, such as an auto pilot, auto thrust control, or flight director, will be considered significant. Second, flight deck upgrades to highly integrated electronic displays would be significant for Part 23 and 25 aircraft. (They are currently significant only for Part 23). These additions would need to meet the latest requirements for such devices.
Interior Modifications
The potential changes impacting interior modifications are still being debated among the agencies. Interior modifications that include changes to the attachment system or changes to the emergency egress path or procedures would be considered significant and would need to meet the latest requirements. A full interior modification – assuming no changes to the attachment system – would not be considered significant. The agencies are undecided on how changing seating configuration through a plate or pallet system assuming there is no change to certificated passenger capacity should be addressed.
NATA Position
NATA will continue to monitor this issue and provide members with updates as available. The association is concerned that some avionics and interiors modifications could be elevated to significant status through revising this AC and, therefore, mandate compliance with the latest requirements, placing an undue burden on NATA’s members without the benefit of full rulemaking.
Status
The FAA, TC, and EASA intend to adhere to the following timeline:
January 2010 – Draft AC published in Federal Register (or equivalent for EASA – TC has no mechanism to collect comment on this type of guidance) with 90 days for public comment
July 2010 – FAA and TC issue final AC (or equivalent)
September 2010 – EASA issues final AC equivalent
Staff Contact: Eric R. Byer
Vice President, Government and Industry Affairs
ebyer@nata.aero
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For general press inquiries, contact Shannon Chambers at 703-298-1347 or schambers@nata.aero.
The National Air Transportation Association (NATA) has been the voice of aviation business for more than 80 years. Representing nearly 3,700 aviation businesses, NATA’s member companies provide a broad range of services to general aviation, the airlines and the military and NATA serves as the public policy group representing the interests of aviation businesses before Congress and the federal agencies.