Turbine blade quality control theft risk

Tom's anecdote distributing worn/defective Pratt & Whitney blades to ~200 high-school visitors in 1995/96, with care taken about cut-corner and notch markings — at $4,000–$6,000 per blade, defective blades stolen and reinstalled could blow up engines.

You might have to make 400 bonds, but if you make one bad one, you've got scrap. You can take a $500 chip — remember I said one of the problems of joining is, if you don't do it well, it comes at the end of the manufacturing process where the cost of scrap is high. You can make a $500 chip that has to have 400 good bonds, and if it has 399 good bonds, it's a $0 chip. Actually it's not zero — they take the bad chips, put an ink spot on them, and sell them as keychains.

Student: I heard that when a Pentium 4 has part of it go bad, it becomes a Pentium 3.

That's what they've started to do. This was a Pentium 1, the 1995 version. The reason I had these — when I first became department head in '95 or '96, they used to bring groups of high school students through MIT, like 500 of them from around New England, top science students in their high schools, and try to give them a Saturday at MIT. They chose materials when I was department head, so we had to put on a dog-and-pony show for these high school science stars. I got Pratt & Whitney to give me — maybe it wasn't 500, maybe 200 students — enough turbine blades that I gave every one of them a turbine blade. These were worn-out turbine blades. A little problem, because you have to be careful about turbine blades. If this blade is worth $6,000 — now this one's cut in two, but even this one's got a corner cut off, and that tells a mechanic, don't put it into an engine, there's something wrong with it. [Tom shows a marked blade.] This one's got a notch right here — don't put it in an engine, it did not pass quality control. When these things are worth four or five or $6,000 apiece, there's a great incentive for people to steal bad ones and put them in engines, which could cause the engine to blow up. That's a quality control concern. That's not a problem with a Pentium chip.