"Peter Duniho" wrote in message
...
"Paul Sengupta" wrote in message
...
Turbines do suffer from manufacturing defects (if I recall, there was
an
uncontained failure in the 90's on some rear-engine jet -- 727, DC-9 or
something like that -- where the blade failure was due to some
metallurgical
problem).

Sioux City DC10.

Not actually the accident I'm thinking of. But yes, that's another
example
of blade failure (did they eventually determine it was a manufacturing
defect, or a maintenance problem?).

They say it was a manufacturing defect about the size of a grain of
sand.

http://www.ntsb.gov/speeches/former/hall/jh970912.htm

"Metallurgical examination of the titanium fan hub revealed that a fatigue
crack originated from an inclusion near the surface of the hub's bore. The
inclusion had been formed during the titanium vacuum-melting process at the
time of manufacture about 2 decades earlier, which developed an internal
cavity during final machining and/or shot peening. At the time of
manufacture, the fan hub had been ultrasonic and macroetch inspected."

The accident to which I was referring only involved one or two fatalities,
of a passenger or of passengers sitting right next to the engine.

Yes, I know the one you're talking about.

It's mentioned on the page referenced above:
"We will soon conclude our investigation on that Delta Air Lines MD-88
engine failure I mentioned earlier. Metallurgical examination of the
fracture surface of that fan hub revealed that a fatigue crack had
originated from a machining defect in a tie rod hole. Further, the fan hub
had been fluorescent particle inspected only seven months before the
failure, when the crack was estimated to be approximately ½-inch long."

Also http://www.ntsb.gov/pressrel/1998/980113d.htm

Paul