It’s not just aircraft owners that ask whether parts manufacturing authority (PMA) parts are as good as original equipment manufacturer (OEM) parts. Many mechanics believe that OEM parts are better and that PMA parts are just not as good. They just don’t want to use PMA parts in the aircraft they are maintaining if OEM parts are available.
Even though PMA parts undergo the same rigorous approval and quality control process as OEM parts, it is obvious to me that many mechanics remain skeptical. When I talk with mechanics — especially general aviation and corporate mechanics — there seems to be a lingering concern that parts produced by the OEM must be better than those produced under a PMA.
Part of the concern appears to be the fact that — in general — PMA parts can be bought for substantially less than OEM parts. The price discrepancies between PMA and OEM parts seem to create the perception that safety — and quality — must reside in the higher-priced product. After all, they’ve said to me, what other reasons could there be for the differences in price?
Well, there are a lot of reasons for the differences in price — which I won’t go into here — but none are related to the safety or quality of the parts themselves. But I understand why mechanics have these lingering concerns.
Many of them arose during the unapproved parts scandals that were prevalent in the industry a number of years ago — and that continue to be a threat to aviation safety warranting appropriate vigilance. Unapproved parts were frequently available at significantly lower costs than approved parts — and the safety and the quality of those parts were unacceptable for use in aircraft. But PMA parts are approved parts and are appropriate for use in aircraft maintenance, just as OEM parts are. The FAA oversees the production of both in the same manner.
No difference in safety
In addition, my experience after almost a decade as a member of the National Transportation Safety Board is that there is no safety difference between OEM and PMA parts. I am not aware of any accident or incident where a properly approved PMA part was deemed to be a causal factor. I am also not aware of any difference in reliability or durability or any other quality-related factor. I would certainly like to hear from any of you who have experienced differences in OEM vs. PMA parts.
I have also had mechanics tell me that they prefer to use OEM parts because it is less time-consuming for them. That is, if they use an OEM part they don’t have to do as much work to ensure that the part being used is approved for the aircraft or aircraft product they’re installing it in. That is true to a certain extent — if the OEM and PMA part numbers are different, a little extra checking is required to ensure that the correct part is being used. But if the cost of maintenance is a concern, PMA parts should be explored as an alternative to OEM.
John Goglia has 40+ years experience in the aviation industry. He was the first NTSB board member to hold an FAA aircraft mechanic’s certificate. He can be reached at firstname.lastname@example.org.