Aero-Tips!

A good pilot is always learning -- how many times have you heard this old standard throughout your flying career? There is no truer statement in all of flying (well, with the possible exception of "there are no old, bold pilots.")

Aero-News has called upon the expertise of Thomas P. Turner, master CFI and all-around-good-guy, to bring our readers -- and us -- daily tips to improve our skills as aviators. Some of them, you may have heard before... but for each of us, there will also be something we might never have considered before, or something that didn't "stick" the way it should have the first time we memorized it for the practical test.

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Aero-Tips 12.05.06

A while back there was a series of advertisements for engine oil that used the tag line, "starting is the worst thing you can do for your engine." The idea was that most internal engine wear happens in the moments after start when oil pressure has not come up, and internal engine parts are rubbing directly against each other.

If your airplane's engine is very cold, oil pressure may take quite a bit of time to come up enough to distribute oil over internal engine parts. In extreme cases the oil may b so thick and gummy that it actually inhibits the smooth motion of engine parts. This is a prime reason we preheat engines in very cold weather -- anything below about 40 degrees F, according to most manufacturers.

Preheat the oil

Most preheaters include a flexible hose. Fire up a (potable) gas-fired heater and shove the hoses into the engine inlets, goes the standard practice. Run the preheat for five or ten minutes, or until the lineboy gets too cold and decides the engine is warm enough. Unplug the preheater, start engines and go.

Trouble is, this process warms only the top part of the engine, away from the oil pan, and if the preheater is only run a few minutes it does even less to warm the engine's oil. By far the best idea is to tow the airplane into a heated hangar to preheat the engine. Barring that, preheaters work, but the standard practice described above won't cut it.

To preheat the oil, which is really the objective, put the preheater hoses not into the engine inlets, but up through the bottom of the cowling near the oil pan. Run the preheater at least 30 minutes; most preheat instructions recommend longer than that. If your engine(s) have electric heaters installed plug them in well before a flight, for most recommend preheating the engine up to four hours to get a true effect-reduced start-up wear.

Aero-tip of the day: Preheat a cold engine... and preheat it right.

FMI: Aero-Tips