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Friday, January 15, 2010

Airplane Story

Marc retold an old airplane story at lunch. I don't recall recording it, so here goes. Stop me if you've heard this before.

Many years ago a guy he knows takes off from the Hillsboro airport in a Cessna 172. He has reached an altitude of 100 feet or so when the tip breaks off one of the blades of the propeller. The tip flys straight to the ground, bounces off the concrete runway, flies back up, hits the plane and punctures the gas tank. Meanwhile the unbalanced propeller has caused the engine to start vibrating madly and before our hero can shut it down, it has broken loose from it's mountings and has fallen off the front of the airplane. Normally, this would be the prelude to a fatal plunge to the ground as the complete airplane is balanced, and without the engine it is unbalanced and unflyable. Fortunately, the engine doesn't fall completely off, it is hanging on by some wires and cables. The pilot is able to turn the plane and land it in the parking lot. He walked away, and as we all know, any landing you can walk away from is a good one.

Update: I got to wondering about just how fast the tip of that propeller was going, and then I remembered that airplane engines need to turn slower than you might want in order to keep the tips of the prop below the speed of sound. I checked out the numbers and for this plane it comes out to 785 feet per second or 0.7 Mach, so it's well under the speed of sound, but still moving at a pretty good clip. Matter of fact 785 fps puts it in the range of a bullet fired from a handgun. So, yeah, wango!

1 comment:

Anonymous said...

Why do you care about this????It's one of those freaky things...It reminds of the the Math classes, where they asked those crazy questions only a genius could answer.....you blow my mind....so did everyone survive