The FAA has published a draft guidance document on new engine components. The FAA has invited the public to comment on this guidance.
The new guidance is tentatively known as Advisory Circular 33.91-1. It would be focused on compliance with the engine component test requirements of 14 C.F.R. 33.91. That rule requires a PMA applicant to conduct tests to demonstrate that the systems or components are able to perform the intended functions in all declared environmental and operating conditions.
The new guidance provides a list of 25 tests that are considered necessary to meet 33.91. Some, but not all, of the 25 tests reference acceptable standards for the conduct of the tests, such as:
- DO-160E Sections 4-14, 16-17 and 22
- SAE ARP5757, Sections 5.4, 5.7, and 5.23
The list of tests also reference certain parameters for the testing.
The guidance also addresses what should be included in a test plan.
It is important for the engine PMA community to examine this guidance, and to let us know whether (1) it provides sufficient guidance, and (2) whether the requirements that it implicitly imposes are broadly appropriate to engine component testing. We have heard from the avionics community that FAA efforts to impose common, broad testing requirements on avionics installations have led to testing requirements that did not always make sense. This AC can help avoid testing requirements that don’t make sense, by setting the appropriate standards, but it is incumbent on our community to make sure that the standards set in the AC are appropriate.
Comments are due to the FAA by April 5, 2010. Comments can be emailed to Marc Bouthillier at Marc.Bouthillier@faa.gov or faxed to (781) 238-7199. We would appreciate copies of your comments, so we can make sure that MARPA supports the industry’s comments and needs.