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system between the flight control surfaces and the cockpit were so badly destroyed by impact and subsequent fire that their condition prior to impact could not be established. No indication of any pre-impact malfunction, failure, or unairworthy condition could be found in an examination of those flight control components that withstood impact and the subsequent fire.
The four Pratt and Whitney, model JT3C—6, turbojet engines were found completely detached from their respective pylons. Nos. 1, 2, and 4 engines were found just forward of their initial point of contact and they were inclined, forward end up, about 30 degrees with their compressor ends resting on the forward edges of the engine impact holes. These engines had rotated about their longitudinal axes in a clockwise direction by approximately the following amounts: No. 1, 15 degrees; No. 2, 80 degrees; No. 4, 45 degrees. No. 3 engine lay upside down about 50 feet ahead of the location of its initial ground contact. All fire damage to the engines occurred after impact. Except for No. 3 engine, which lay in a general ground-fire area, fire damage was localized and caused by spillage from broken fuel lines, fuel pumps, and fuel controls.
The engines and accessories were shipped to the American Airlines shop at Tulsa, Oklahoma, where they were disassembled. No evidence of operational failure or distress was revealed during the disassembly and examination. All engines were producing appreciable power at impact. Nos. 3 and 4 engines were more severely damaged by rotational interference than were Nos. 1 and 2. Engine instrument readings obtained were so variable that no pattern could be established; however, the oil temperature gage readings were No. 1, 105 degrees c., No. 2, 105 degrees c., No. 3, 70 degrees c.; and No. 4, 74 degrees c.
The hot sections of all engines were free of any evidence which would have indicated they had been subjected to over temperatures. Bearings of all engines were normal except for damage resulting from impact loads and the drying effects of heat from the ground fire.
Maintenance records were reviewed, nothing of an unusual nature was found.
N 7514A was equipped with a Lockheed Aircraft Service, Inc., flight recorder in accordance with Sec. 40.208 of the Civil Air Regulations.[1] The record made by this instrument provides information enabling reconstruction of the complete flight path. The flight parameters are recorded by styli, which are mechanically linked to sensors and move vertically across a foil tape. As the aluminum alloy foil is fed past the recording styli, lanes are embossed on the surface. One spool will accommodate approximately 100 feet of foil, which allows approximately 150 hours of recorder operating time.
The flight recorder installed in N 7514A was a model "C" recorder, serial No. 107, and was certified as meeting Federal Aviation Agency Technical Standard Order C-51. It was severely damaged by crushing and fire, however, most of the recorder mechanism was functional. The recorder was opened at the scene of the accident and a preliminary reading of the data was made by a Board employee.
- ↑ Sec. 40.208 reads "A flight recorder which records time, airspeed, altitude, vertical acceleration, and heading shall be installed on all airplanes of more than 12,500 pounds maximum certificated takeoff weight which are certificated for operations above 25,000 feet altitude, and shall be operating continuously during flight."
