Warbirds Sitting For Awhile

[Ed Likes]

Maybe this subject has been covered. But Iam the owner of a classic car, and in the car world if a restored car sits for a period of time your looking at replacing brakes, hoses, seals, etc. I feel that if you don't start your car up, and drive it a few miles at least once a year your looking at problems.
Now I would think that the basic principal applies to warbirds that have been restored to flying condition as well. So my question is roughly how long can a restored warbird that is a flyer sit before your looking at going thru a lot of things to keep it airworthy? Case in point might be the Collings P-38 it is a flyer, and a fantastic looking aircraft. But I don't think it has flown for awhile. Im using this as an example not picking on Collings as first of all Im a supporter of Collings. But if the engines are not being run up once in awhile, and this aircraft, or any aircraft sits seems like things are going to start to develop leaks etc. Chime in with your thoughts on this.

[JohnB]

Well, there is one major difference, airworthy aircraft require annual inspections.
Good thing too since with an old car a minor issue might leave you stranded on the side of the road, cell phone in hand to AAA...while in an airplane you might make the news or the wreck page of Air Classics.

And with cars, the need for ongoing maintenance while in storage depends on the car. Typically, the older, the less critical.
My 1914 roadster is always ready to go in the spring, check the tires, take it off the jacks, just prime it and press the starter button to turn it over a few times with the ignition off.

Not so with new cars. On my other cars, I move the battery charger to each of them monthly.
A few years ago, the Ferrari expert for Sports Car Market wrote about a low miles 90s Ferrari he bought in Hawaii.
When he got it, he had to spend $20,000+ to get it funny g properly again. He said most of that could have been avoided if the previous owner had burned a tank of fuel in it every year instead of letting it become garage art.

[marine air]

I was talking to the owners of the prototype Yale (BT-14) at Oshkosh a few years ago. The aircraft had been in a hangar in a dry , hot part of Texas for about thirty years in storage before they bought it. They said all the rubber components had to be replaced but that everything else fared very well. I assume they meant tires, tubes and hoses. The engine turned out okay . I got my dad's J-3 Cub flying after it sat for about five years. It looked cosmetically perfect. However the exhaust was corroded internally and the entire system had to be replaced. Everything had to be greased and oiled as the trim tab , throttle, mixture, carb heat. and other items were very stiff. every inch of the cables were cleaned and then oiled. The tires had flat spots but we increased the pressure from 12 to 35 psi and moved the airplane around every few days. eventually the flat spots smoothed out and the tires were again round.
The compressions were very low and I ran an oil additive and ran the airplane on the ground for about five hours. YOU will want to change out the oil and gas before attempting to run the engine. Luckily the magnetos and carburetor were okay. The compression improved over the next 25 flight hours until they were back in the 70's. You really have to go over inch of the airplane. I also hand washed the airplane as there was a very fine grit in the fabric. then I hand waxed it with a carnauba wax to help reinvigorate the fabric.
When you start flying an airplane that has been sitting a long time, you are the "test pilot." Don't assume nothing else will fail on it. After flying about ten hours it developed a fuel leak and the compass started leaking. The orange hoses also had to be replaced even though they looked perfect, they were dry rotted. After about $3500, and a lot of labor the airplane is mechanically perfect and almost cosmetically perfect.