Thursday, April 1, 2004
The Ultimate Preflight
The assumption that the airplane has always worked in the past is no excuse for a hasty inspection
The operative word there is “almost.” “Almost zero” isn’t zero. Although we’ll never get an airplane to be 100% in terms of condition, wouldn’t it be silly to get hurt just because we didn’t bother to spend an extra five minutes and missed a loose nut or a crack that was right there, ready to be discovered?
Not everything that goes wrong with an airplane is catastrophic, but who wants anything to be wrong with their airplane? Here are some examples of glitches found in our personal airplanes during preflights over the years: a dozen or so broken exhaust stacks, a broken (not cracked, but broken) motor mount, one of the main through-bolts holding the engine case together was lying in the bottom of the cowl, a cracked oil cooler, leaking brake calipers, a cracked scissor link on the nosegear, etc.
Realistically, there are limits to what we can actually inspect during a preflight because we don’t have access to the entire airplane without pulling out panels. In many cases, we can’t even do a thorough inspection of the engine compartment because the cowling only has an oil door. Still, we should avail ourselves of what access there is and do our best to make sure there isn’t a gremlin hiding in a corner somewhere that’s just waiting to bite us in our personal empennage. So, if we can’t pull out panels, just what can we check on a normal walkaround that’s often overlooked?
Most POHs include a little walkaround map that usually starts with checking the oil on the right side of the engine cowl. We’ll start in the same place and slowly work our way around the airplane back to where we started. Before we start, however, we’ll assemble a paltry toolkit that includes a screwdriver/fuel tester, a clean rag and a flashlight. At least the first preflight each day should be done with a flashlight. Ideally, a flashlight should be used on all preflights.
When loosening the dipstick, see if there’s any “give” in the oil fill tube. If it’s loose where it screws into the engine case, it’ll start leaking there.
How does the oil look? Clean? Dirty? Dead black? Maybe it’s way past the time to change it. And what’s the level? Look in the POH for your engine and stay well above the minimum oil level indicated. If the oil is at a minimum or running low, that’s because it’s either leaking or burning. So, if you take off with it low, it’s going to be even lower (or gone) later in the flight. Fill it up above minimum!
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