Which is better?

While the extra low time bird can be desirable from a resale standpoint, we need to ask how much sitting around lately has the plane had? If it is one of those that has been mostly sitting around for the past several years, and just gotten an annual to make it “airworthy” again, there are some considerations to ponder:

1. Expect some rubber seals to start leaking once the plane starts regularly flying again such as in the prop seals, hydraulic seals, engine gaskets, and even perhaps fuel tank sealer, etc. Idle rubber does not get lubricated and can harden and crack prematurely.

2. While avgas is of a much better quality than car gas, gas is gas, and deteriorates somewhat with age. If the plane has been at rest for some time and the tanks are full, consider changing the fuel prior to running the engine.

3.  Is the annual inspection bringing the sitting aircraft a real inspection that includes checking all things that can be a factor a bit down the road? By this I mean, did they check to see if the carburetor or fuel system up to date? In the IO-360, does it have the new style fuel injector? Here’ s how you can tell this: Inspect the fuel controller at the bottom of the engine on the pilot’s side. The fuel controller is where the throttle and mixture cable attaches to control the controller. There is a hex type nut on the side of the fuel controller. If it is a dark colored hex nut with a set screw in the middle of it, you have the old style fuel controller and should have it overhauled to insure safety. (I have now had 3 complete engine failures in flight in my 30 years of flying, and all 3 were due to a faulty fuel injector controller, twice in the same plane, but that’s another story). If the hex nut is brass in appearance, and has no center set screw, you have the late style injector and is less likely to fail.

4. Finally, but not really finally, is to find out how this engine was cared for during the idleness of not flying. If the owner tells you that he went out to the airport once a month or so, started and ran the plane on the ground, be careful of this engine. It may have lots of water and rust inside of it. Why? Well, all engines accumulate water through condensation. That condensation settles down in the oil pan below the oil level. Simply ground running the engine may not yield the 180 degrees necessary to boil the water off, and it may just circulate throughout engine system, coating the cylinders, rings, cam, crankshaft, etc. with water along with the oil. Now, you may think that the chrome cylinders and throws of the crank and cam are chromed which will fight rust. You need to realize that if you have chrome cylinders, you have steel rings. If you have steel cylinders, you have chrome rings. The chrome on the crankshaft throws ends at the end of the throw, and it is common to get rust at the end of the chrome plating where it meets the steel of the rest of the crankshaft. Rusty crankshafts have been known to break at the edge bead of chrome throws and throw the whole propeller off of the engine. The rust had simply eaten beyond the strength of the crankshaft, and there it goes.

It is also important to have your inner cylinders inspected. A bore scope inspection is best, but not everyone has access to a bore scope. Your mechanic can start off by visually inspecting the inner cylinder through the spark plug hole to see if there is any rust present. He cannot see the rings, but he can see the cylinder walls. If the cylinders are steel and rust pitting is obvious, you are probably looking at a top overhaul in the near future, as that rust will cause cylinder walls and even the chrome rings to deteriorate. If you have chrome cylinders, it may be a good thing to remove the cylinders and replace the steel rings. This is much less expensive than a top overhaul. Once the cylinders are off, an inspection of most of the engine components is possible and rust problems can be now seen near everywhere.

Bottom line here is that there are always exceptions, but it is best to check all aircraft you are considering purchasing as thoroughly as possible, but be especially concerned about the super low time birds out there.

My bottom line is: Don’t buy any Mooney simply because of its total time. If you find a bird that meets your requirements, check it out thoroughly and do not limit yourself to purchasing only a low time airframe.

Fly safe,