Thursday, March 20, 2003
WHEN YOUR PLANE TRIES TO TELL YOU --
Once upon a time your author had a new pattern plane. On the first few days of flying it, everything was fine. But one day, on the first flight, it required several clicks of down trim (odd...) after take off -- and after each turn or maneuver, the pitch trim would be off again (VERY odd...). Only when it took full down stick to fly inverted (JEEPERS!) was your author smart enough to realize something was wrong. After landing, the problem was obvious: I had not bolted the wing to the fuselage!
But the plane DID "try to tell me"; I just wasn't listening. Only new, tight-fitting wing dowels had saved the plane from destruction -- it certainly wasn't the pilot! Recapping later, I thought of a number of things that would have caused similar symptoms: servo or servo tray loose, bad servo centering, broken elevator hinges, loose control horn, et cetera. The point is, ALL of those things are BAD! And with the plane not behaving properly, WHY did I keep flying??
Just suppose you're getting an occasional glitch from your radio; something that doesn't normally happen. This could be an antenna problem; it could be metal-to-metal vibration causing home-grown interference, or a loose crystal. Will any of these get better while you keep flying? And speaking of vibration, what if you start hearing it in the air? It's your plane talking to you -- loose muffler, engine mount, worn wing dowel holes, loose cowl mounting. Again, such problems don't get better, only worse.
One more example -- this has happened to all but the most careful pilots. Your engine goes lean and sags at the top of a loop. It's TELLING you that the mixture is loo lean. But you don't listen and keep flying; a minute later, while doing another loop, you're suddenly dead stick!
The sky gods know -- we have enough problems that pop up suddenly, and we don't have any opportunity to prevent them. Other times the plane "tells you" that there is, or will be, a problem. Unless you really enjoy repairing or rebuilding -- LISTEN! Cutting a hop short to check out a possible problem is much quicker (and vastly cheaper) than building another plane!