A PMA applicant must assigns a part number to the PMA part. The nature of that part number was a topic of discussion at a recent industry meeting, the 2011 Gorham Conference.
Generally speaking, a PMA part usually needs to have a different part number from the OEM corollary part that it replaces. The part number must be different in order to distinguish the source of the part and to avoid confusion between the PMA part and the OEM corollary. There is case law that has suggested that alternative part number can rely on the OEM part number as a root, as long as it includes a suffix or prefix that unambiguously identifies it as something different (or as coming from a different source). The PMA Order, FAA Order 8110.42C, further refines this guidance, explaining that
“Adding a prefix or suffix to the TC holder’s part number is enough as long as the prefix or suffix does not compromise the TC holder’s part marking practices. The applicant may also use a prefix or suffix to satisfy 14 CFR § 45.15(a)(2) requirements for marking the part with a name, trademark, or symbol. This only applies if the prefix or suffix is consistent across the applicant’s product line. Also, each part bears “FAA-PMA” to meet another 14 CFR § 45.15 requirement.”
At the 2011 Gorham Conference, Ed Bayne of Boeing explained that when a PMA is issued for a part based on a licensing agreement with the OEM, the PMA parts number can be identical to the OEM part number, if the OEM has licensed the trademark associated with the part number (or the part number may be different depending on the business relationship between the parties). Bayne explained that independent PMA parts, on the other hand, must have a different part number.
One practical reason for the part number distinction is to avoid confusion as to source in the marketplace. Such confusion could lead to a Lanham Act (trademark law) violation. Where the OEM has licensed the use of its trademark, however, there is no basis for believing that there is a violation.
Darren Lovato, a well-known Designated Engineering Representative (DER), noted that for supplier part numbers, if the TC holder purchases a part from a supplier and it is approved under their TC then they can carry-over the part number. In such cases, the supplier owns the trademark on the part number as the prior user, and the TC holder’s use of the part number is merely an accurate description of source.