Wednesday, June 07, 2017

Q-Tips and Canoes

En route to a busy GA aerodrome, I checked the ATIS and started setting up for the runway in use. I needed one more approach before the end of the month to maintain my IFR currency, and was planning on flying it simulated just to get that box ticked. The time then passed the top of the hour, so I checked again, and discovered that the runway with the approach was now "closed per NOTAM" and the cross runway, with no instrument approach was in use. Unexpected, but perfectly manageable. On final I saw a light twin and a pick up truck on the grass at the side of the runway. Something had not gone well for someone.

I landed without incident and taxied to the FBO, where we learned that the disabled aircraft had had a gear collapse, a term which the FBO staff seemed pretty sure had been applied euphemistically to a situation where the pilot had neglected to extend the landing gear. The poor airplane was lifted back to its wheels and towed past the windows of the FBO, where I pointed out to my non-pilot co-worker the characteristic Q-tipped props of an aircraft that lands gear up with the engines powered. I paused as I wrote that. Of a propeller, Q-tipped refers to the ends being bent over. I've always called them that, and I remember the first time I saw a Q-tipped prop, on a fixed gear single whose pilot had tried to make it stop flying and land on a short runway, rather than going around and trying again with a better short-field approach. I think someone with me must have called them that, and I absorbed the term. Searching for an etymology, I discovered that there is a company that makes Q-tip propellers on purpose (and a funny story about an FAA inspector who didn't know that). Trying to find when they were invented, to help determine whether the company was named after the condition or vice versa, I wandered down a rabbit hole of the history of the tip-fin propeller, invented by J.J. Kappel, initially for marine applications. If anyone knows when they were first put on airplanes, let me know. I had to escape from articles like this one before I got wrapped up in the physics. This was meant to be a quickie blog entry.

So we're watching the remains of this once-airworthy vessel towed past, and the FBO staff are all fixated on it. One of them is scrambling for a ramp pass so he can drive down and check it out. My co-worker is confused about the excitement. "Remember how much we had to spend to get the engines overhauled on [the new plane we just bought for our fleet]?" I asked my co-worker. "The engines on the gear-up plane, no matter how new they are, are done now." The force of the prop strike bends and breaks other components of the engine.

"But what's the spectator value?"

I thought about it a while and finally came up with an analogy he could appreciate. He's an outdoorsman. "You know when someone drives their van into a parking garage or under a bridge with a canoe on top? No one is hurt, but the canoe is destroyed, and the van is damaged, and the person who did it is in emotional pain from how stupid they just were, and how much money they just destroyed. And everyone comes to look, and take pictures. You feel the pain, and you're so glad it wasn't you, because you know it could have been you." He got it.

1 comment:

Sarah said...

The shutdown checklist after an inadvertent gear-up landing: "Select landing gear position: down"

I assume you've seen this video, of a "rejected" gear up landing... This pilot climbed away with 2 bent props and flew home to have them fixed! Not a smart thing to do - in this case, he or she had to know what they did.

But sometimes it's not so apparent. Our club Citabria had a prop strike from a nose low hard landing, and the instructor elected to push in the power and go around to a normal landing. On putting it way the prop tips were noted curled and the plane was grounded until a replacement prop & engine teardown was done.