An apprentice is working on the left engine and she shows me the broken tach cable. It has broken fairly near the engine end. "How do you get the rest of the cable out of the housing?" I ask.
"That's what I was wondering," she confesses.
The engineer explains, "Normally, you would push it out with the new cable as you installed it, but because we're converting to the digital system, it will just stay in there."
"Forever? Like a mammoth preserved in a tar pit?" I am enamoured of the image of this historical piece of airplane entombed in its housing for all time. "But how does the new one work without a cable?"
Apparently it determines up the propeller rpm from the magnetos. I think this is every bit as cool as the picture on an iPod shifting from horizontal to vertical when you tip the device. It's probably just as simple, more a breakthrough in someone thinking of doing it that way than in the technology itself, but I will be pleased to never see another broken tach cable again, even while I am carrying a fossilized one around.