Quick Drain


The shop changed the oil in my retractable single and replaced the brake pads. The logbook entry stated they had changed the oil and filter, installed a “quick-drain” oil plug, changed the brake pads, etc. After any kind of maintenance, I’m pretty leery of flying the airplane, so I did a very thorough walk-around: oil level on the dipstick, no leaking from the oil pan plug, full fuel tanks, good flight control surfaces, etc. “Okay,” I thought. “Good to go.”

I had planned to visit nearby airports for practice, but the winds were unfavorable, so I remained in the pattern. Off I went, making one circuit to a full-stop and taxi-back, before taking off again. A touch-and-go was next, and on climb out before turning crosswind, I heard a “ZZZZZZZZZ!!” The propeller went to a very high rpm, like 3600 or so, when 2750 is max. My heart pounded, and I pulled the prop control back, turned crosswind, then downwind and heard the “ZZZZZZZZZ!!” again, followed by propeller surging.

“Holy moley! I gotta get this thing on the ground,” I thought. I was on downwind, slowed, got the three green gear-down lights and was cleared to land. I looked down at the oil pressure gauge—it read nine psi. NINE?! It should have been closer to 60.

I landed uneventfully and rolled to the end of the runway, and then taxied back to the shop. Just as I tried to stop, facing the hangar, the left brake failed. Fortunately, I was going slowly and, to test it, I did a 360 and stopped, facing the hangar—nope, no left brake. I shut down and looked under the aircraft. There was a large, wide trail of oil and a puddle of brake fluid around the left brake. Again with the “holy moley.”

The mechanics drained about 2.5 quarts of oil out of the 10-quart crankcase, and said the engine would have to be removed and torn into, inspected by an expert at another shop, in case of damage due to running it low on oil. It may have to be rebuilt, they said. The shop was very apologetic, over and over and over, and said they wanted to give the airplane back to me with a better engine than when they received it.

How did the oil leak out? The “quick-drain” oil plug protruded far enough down so that when the gear was retracted, the nosegear contacted it and pushed up on the quick-drain release, draining the oil, much of which now was on the airplane’s belly. The mechanic thought he was doing a “good thing” by installing a quick-drain but he didn’t check to see if there would be adequate clearance when the gear was retracted.

Lesson? Make sure any new part added to the aircraft will work. I should have ensured the shop swung the gear to check for clearance on that fancy new, blue-colored, quick-drain oil plug. Of course they hadn’t, and had I flown about five minutes longer, the engine would have seized. That was after only flying for about 10 minutes. Just think if I had left the pattern. The left brake failure? A mystery, but it can’t be a coincidence.

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