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To: Fixit
From the NTSB Safety Recommendation A00_121_124, dated December 12, 2000, dealing with an on-ground unconstrained engine failure of a GE CF6 mounted on a Boeing 767 (see http://www.ntsb.gov/recs/letters/2000/A00_121_124.pdf).

"This incident raises serious safety concerns because, if it had occurred during flight rather than on the ground during maintenance, the airplane might not have been able to maintain safe flight. Examination of the airplane revealed that a portion of the HPT stage 1 disk penetrated the left wing just inboard of the No. 1 engine pylon. Investigators determined that this portion of the disk, which is approximately 140 square inches and 45 pounds, penetrated a dry bay, made a 1-inch-wide vertical cut through the lower half of the forward wing spar, and penetrated a fuel tank before exiting through the top of the wing and passing over the fuselage. Examination of the engine revealed that the disk rupture split the engine in half, leaving the rear of the engine joined to the front only by the fan midshaft. The disk had separated from the shaft and was completely missing from the engine. Two pieces of the disk, which amounted to about two-thirds of it, and three blade slot posts were recovered. Although an extensive search was conducted, the remaining one-third of the ruptured disk (the piece that passed through the wing) was not recovered. Trajectory analysis performed by the Safety Board indicates that it may have landed in the Delaware River, which is adjacent to the airport."

The problem is that the wreakage fell into 4 areas -- the wing pieces in the Bay, the gas station, the main wreakage, and additional unspecified wreakage several blocks away. It seems very improbable that an "unconstrained engine failure" would cause the breakage of the airplane into those separate parts. However, if the rear part of the spool disintegrated, it may be possible to break the wing spar causing the wing to break, and this might strike the tail surfaces.

It is unclear from ongoing TV reports whether the debris in Jamaica bay is wing or tail. An early report said that the divers in the Bay were searching for the flight recorders, which would indicate that it is the tail section. The recorders have been reported as found, but I haven't heard where they were found.

13 posted on 11/12/2001 10:50:42 AM PST by Lessismore
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To: Lessismore
Great find!

That article you found might merit posting on its own thread.

14 posted on 11/12/2001 11:00:27 AM PST by Fixit
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