When an Airworthiness Directive (AD) affects an aircraft, how do you get your part on an aircraft? If the AD affects your part, then you may need to obtain an Alternative Method of Compliance, or AMOC from the FAA.
When does the need for an AMOC occur? When PMA parts are designed to replace a flawed OEM part, it sometimes happens that the flawed OEM part becomes the subject of an Airworthiness Directive. If the AD inhibits the use of the PMA part, then an AMOC may be needed to use the PMA part. Restrictive ADs can also arise in the context of certain types of flight-critical parts, like the SFAR 88 CDCCL issue, which required strict compliance with manufacturers manuals (new CDCCL guidance is also open for comment—this was discussed in last month’s MARPA Supplement and also in the MARPA Blog).
Where an AD restricts the parts that are permitted to be installed, that AD is a rule so compliance with the AD is required. Deviating from the rule requires explicit FAA approval. The normal method for deviating from an AD is the AMOC route.
When an AD requires an OEM part, the PMA alterative may be as safe as or even safer than the OEM alternative; but in order to get it on the aircraft an AMOC applicant must prove that the part meets the safety standards that are being addressed by the AD (including all applicable regulatory standards). The procedure for obtaining an AMOC is discussed in 14 C.F.R. § 39.19. Once this showing is made to the satisfaction of the FAA, the applicant may be entitled to FAA approval in the form of an AMOC.
FAA Flight Standards guidance on coordinating AMOCs is found in FAA Order 8900.1 (this Order is the FAA inspector’s handbook for Flight Standards inspectors). This guidance explains to FAA Flight Standards Service employees how to process AMOC applications. A proposed change to this Order is open for comment.
The change would create a new Chapter 59 in Volume 3 of 8900.1. It creates three new sections in this Chapter (they are numbered 2-4 … there does not appear to be a section 1).
Proposed Chapter 2 establishes general processing standards for AMOC applications.
Proposed Chapter 3 explains when and why an AMOC may be necessary and provide more details on the process for assessing the AMOC application.
Proposed Chapter 4 lays out guidance for processing urgent AMOCs to avoid significant air transportation disruptions.
URLS for finding the proposed language are below. MARPA Members are encouraged to file comments by March 8.
Comments may be submitted to Andrew R. Allocco of the FAA by email to firstname.lastname@example.org or by fax to (202) 223-4615. MARPA asks that you send a copy of your comments to the Association by March 7 so that we can make sure that our comments reflect the opinions of our members.
Chap 2: http://www.faa.gov/aircraft/draft_docs/media/V3_C59_S2_coordination_copy.pdf
Chap 3: http://www.faa.gov/aircraft/draft_docs/media/V3_C59_S3_coordination_copy.pdf/
Chap 4: http://www.faa.gov/aircraft/draft_docs/media/V3_C59_S4_coordination_copy.pdf