General Electric CF6-6 engine fan rotor failure

Referenced implicitly via the Sioux City discussion and GE's 99.75% reliability statistic. Frames the cost economics: turbine blades are 20% of GE revenue but 40% of profit.

Turbine blades constitute 20% of the revenue of one of the big engine manufacturers, General Electric — but 40% of the profits. Not just anybody can go out and make one of these things. There's a lot of technology, a lot of know-how, and if it's commercial you have to get FAA approval. So the OEMs — original equipment manufacturers — the Pratt, the GE, the Rolls-Royce, they guard this viciously, because this is 40% of their profit. This is the core of their business: to make these castings. The American Institute of Physics came up with the twenty greatest achievements in physics of the 20th century, and they included the metallurgy of making these things as a triumph of physics. The physicists couldn't even spell "metal," but anyway.