General Aviation: The First Flight After Maintenance
By Matt Johnson
Flying has always had its dangers — and one of the biggest dangers is flying an aircraft the first time after maintenance has been done to it.
So I should ask myself if, say, the engine sputters or the prop goes into an overspeed condition or I notice the oil temperature is spiking or a cylinder is running very hot: “What changed between this flight and the last?”
Did the mechanic remove — and hopefully replace — the oil? Or did they get distracted by a text or email or phone call or social media post and forget to put oil in? Or forget that little “crush washer” around the oil drain plug?
Did they do anything with the hydraulic system?
How about the electrical system which, it turns out, is really, really complicated and has tons of wires like a pile of spaghetti and is all hidden from view, anyway, so even if I was Nikola Tesla I couldn’t figure out if there was something wrong with it, much less in flight?
Did they add fuel or drain any?
How about the control surfaces — are they attached and do they move in the proper directions when I move the stick and rudders?
A major error in maintenance — not caught by me in a not-good-enough walkaround — almost got me.
A mechanic worked on my aircraft for six (SIX!) months, gave it back to me with almost-empty fuel tanks. A poor preflight by me missed that one, though I caught several other things.
I guessed at the amount of fuel in the mains because the gauges were bad, and believed my buddy who looked in the front auxiliary tank and said it was full. It was, if by “full” he meant “full of air.” We lived, but barely.
Another time, a mechanic installed new brakes, then reinstalled the brake lines so that they rubbed on the brake discs and severed the lines. Again, the walkaround didn’t catch it. But it really gets your attention when you try to stop, let me tell you.
Another mechanic forgot to fasten a bolt with a locking device on a brand-new cylinder and, well, let’s just say that if you do that, bad stuff happens. This error wasn’t visible on the preflight.
I hope NOW I’ve had enough scares to realize that I just cannot trust maintenance 100%.
Not Just Flying
A non-flying story: Just the other day we were using a hydraulic scissor lift to do some work near the ceiling in a hangar. We were hanging some disco balls, but not for parties — these shiny silver balls are to scare off birds.
My fellow pilot raised himself to the ceiling, but later couldn’t get the lift to come down.
Nothing we could do with the device — and we tried everything, including creative cussing — would bring the lift down.
There was no emergency hydraulic release like on a hydraulic floor jack, although there were electrical switches on the side of the machine complete with little pictures on how to electrically lower it in case of malfunction. They didn’t work.
Finally we called the people we rented it from, and they came over, opened up the inside, and found a wiring harness and plug detached, they said, by a new young mechanic. He forgot to reattach it.
Our using the lift was the first time since he had worked on it — the first “flight” after maintenance.
Back In The Air
Another time I had two cylinders running hot in my Lancair IV and had my local mechanic look under the cowling. He undid the last screw, lifted the cowling, and there was a rag stuffed in between two cylinders — stuffed in there by another mechanic who had taken me aside and warned me, some time before that, in a very serious tone of voice to “do a very good walkaround after maintenance.”
I took a picture of it and sent it to the guy saying “I found your rag.” He hasn’t responded yet, but it’s only been four years.
So after maintenance, maybe I should:
- Look closely — very, very closely — at the aircraft and the logbook.
- Do my best walkaround ever.
- Stay in the pattern on the first flight, within gliding distance of the runway.
- Say to myself: “I bet there’s something wrong. Look for something wrong, look for something wrong. It just came out of maintenance, and they were turning nuts and bolts and screws…”
- Do not assume the mechanics did it right.
Distractions
These maintenance errors I described are from all different mechanics, in different states — Missouri, Maryland, Virginia, West Virginia, and Minnesota — so it’s not “something in the water” that is affecting a pocket of mechanics.
I watch mechanics when I enter their maintenance shops. They’re all usually checking their cell phones, like people do nowadays.
Maybe that’s what the guy was doing when he put my cowling back on with rag inside — he stuffed the rag there “just for now,” answered a text or took a call or something else broke his focus.
Not all mechanics get distracted by cell phones of course. Look at the Wright brothers — they practiced “cell phone discipline” and refused to even own one.
All kidding aside, if mechanics are human and can make a mistake that’ll down my aircraft and maybe kill me, it makes sense to do a very thorough post-maintenance walkaround. And a very careful post-maintenance flight.
A careful examination of the logbook and an extra-vigilant preflight can prevent me from taking off, having a problem, and landing out in the middle of nowhere versus landing at my home airport.
