The aircraft parts controversy: automotive parts in airplanes??

A contribution to the on-going discussion about using non-certified parts in privately owned aircraft.

Submitted by Ben Favrholdt, N66MX, Porterville, CA

Fifty years ago, there was no FAA. It was the CAA (Civil Aeronautics Administration). Airplane manufacturers used off-the-shelf automotive parts for lots of their accessories. Beech used car door handles for the Bonanza and Staggerwing, and so did Stinson. They also used automotive starters and generators. The Mooney Mite used a car windshield wiper motor for the gear warning, and a motorcycle battery, and motorcycle brakes. They also used industrial tires. This was all spelled out in the TC (Type Certificate).

When the FAA many years later discovered that some parts like this also wound up in airliners --called bogus parts, they had a fit. They then mandated that any part installed in a certificated airplane had to be traceable to an FAA approved manufacturer. So today, you still see auto parts in certificated airplanes, like my Cessna 150 uses a Ford alternator, and a Delco starter, but these parts were shipped from the manufacturer to an FAA approved facility for testing and the all important FAA-PMA stamp (PMA = Parts Manufacturers Authorization).

So what can the FAA do about people installing unapproved auto parts in older airplanes? Not Much. The TC is the bible for any airplane. The TC would have to be amended by the FAA and approved by the manufacturer. This can be a bit sticky for planes like the P-51, since the manufacturer (North American) no longer exists. And Mooney Aircraft is certainly not interested in getting back in the Mite business. Besides they no longer own the TC. So it appears that the 'grandfather clause' rules. Fortunately for the FAA, the number of older airplanes is small, so the risk factor is not great.

One thing to say for Mooney back in those days is that all the Mite structural parts, such as wood for the wings and fuselage, were all of approved aircraft quality. The Piper Cub in those days used 1020 steel for the fuselage. That is a mild steel, and now all ragwing aircraft like the Pitts, Husky and Citabria use 4130 steel.

So you can't really fault the FAA for tightening the rules in the interest of safety, but things can get a little out of hand. Example: The Ford voltage regulator for my 150 costs about 180 dollars. The identical regulator from a Ford dealer, costs about 30 dollars. Same part number, but it doesn't have the FAA/PMA stamp on it.