Have you ever scolded your dog for excessive barking, and then discovered that there was actually an intruder on your property? Or maybe goaded an apparently lazy horse before discovering a problem with the harness, or something caught in its hoof? This is the feeling I have for this poor hardworking airplane. It tried to tell us. We should have believed it instead of maintenance. But we didn't recognize what it was trying to say.
My coworker reports that the airplane ran perfectly for the rest of the day's work, with no surging or abnormal indications whatsoever. She said she was ready to believe I had been hallucinating and then she left to take the airplane south for scheduled maintenance.
Halfway to the maintenance facility, she experienced the same indications as I had. Maintenance determined that that engine was only operating on five cylinders. The poor thing. A four cylinder engine that is down to three cylinders shakes the whole airplane and tells the pilot with certainty that you had better land me soon. This was so subtle we were all willing to believe it was just a gauge. Thanks, engine, for doing so well for those last twenty hours despite your handicap. I promise to give you an extra ration of oil or something (how do you reward an engine?) when you get back.
I think of my engines a bit as if they were horses and I've just figured out why. It's not that we think of them in terms of the number of horses inside that cowling--thought I'm sure that starts the thought processes down the right path--it's because in the wintertime I put engine tents on them. The engine tents are made of the same sturdy quilted material as horse blankets. You walk up to the side of the engine, making sure it's reasonably clean first, and place the blanket high on the withers, um I mean the front of the cowling, pulling it back and securing it under the belly with velcro or other straps. You smooth it back, make sure that it's even and secure, and I can never, at this point, not pat it gently and speak a few words of praise.
My engines work hard for me, and I want to take good care of them. I still have to be careful that they don't kick or bite me though.
I didn't get a chance to say sorry to that airplane, or find out in more detail the nature of the cylinder problem, because while it was in maintenance I was moved on to the next job on another airplane, in another province.