Accident Boeing 747-131 N93119,

ASN Wikibase Occurrence # 324416

Date:	Wednesday 17 July 1996
Time:	20:31
Type:	Boeing 747-131
Owner/operator:	Trans World Airlines - TWA
Registration:	N93119
MSN:	20083/153
Year of manufacture:	1971
Total airframe hrs:	93303 hours
Cycles:	16869 flights
Engine model:	Pratt & Whitney JT9D-7AH
Fatalities:	Fatalities: 230 / Occupants: 230
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	13 km S off East Moriches, NY - United States of America
Phase:	En route
Nature:	Passenger - Scheduled
Departure airport:	New York-John F. Kennedy International Airport, NY (JFK/KJFK)
Destination airport:	Paris-Charles de Gaulle Airport (CDG/LFPG)
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
TWA Boeing 747 N93119 arrived as Flight TW881 from Athens at New York-JFK at 16:31. The airplane was refueled at JFK and remained at gate 27 with the auxiliary power unit (APU) and two of its three air conditioning packs operating for about 2 1/2 hours until it departed as TWA flight 800. The flight was scheduled to depart JFK for Paris about 19:00; however, the flight was delayed because of a disabled piece of ground equipment and concerns about a suspected passenger/baggage mismatch. The aircraft was pushed back from the gate about 20:02. Between 20:05 and 20:07, the flight crew started the Nos. 1, 2, and 4 engines and completed the after-start checklist. The flight crew then received taxi instructions and began to taxi to runway 22R. While the airplane was taxiing, about 20:14, the flight crew started the No. 3 engine and conducted the delayed engine-start and taxi checklists.
At 20:18:21, ATC advised the pilots that the wind was out of 240-degrees at 8 knots and cleared flight 800 for takeoff. After takeoff the pilots received a series of altitude assignments and heading changes from New York Terminal Radar Approach Control and Boston ARTCC controllers. At 20:25:41, Boston ARTCC advised the pilots to climb and maintain FL190 and expedite through FL150.
At 20:26:24, Boston ARTCC amended TWA flight 800's altitude clearance, advising the pilots to maintain FL130. At 20:29:15, the captain stated, "Look at that crazy fuel flow indicator there on number four .. see that?" One minute later Boston ARTCC advised them to climb and maintain FL150. The crew then selected climb thrust. After a every loud sound for a fraction of a second, the CVR stopped recording at 20:31:12. At that moment, the crew of an Eastwind Airlines Boeing 737 flying nearby reported seeing an explosion. The aircraft broke up and debris fell into the sea, 8 miles south off East Moriches.

PROBABLE CAUSE: "An explosion of the center wing fuel tank (CWT), resulting from ignition of the flammable fuel/air mixture in the tank. The source of ignition energy for the explosion could not be determined with certainty, but, of the sources evaluated by the investigation, the most likely was a short circuit outside of the CWT that allowed excessive voltage to enter it through electrical wiring associated with the fuel quantity indication system.
Contributing factors to the accident were the design and certification concept that fuel tank explosions could be prevented solely by precluding all ignition sources and the design and certification of the Boeing 747 with heat sources located beneath the CWT with no means to reduce the heat transferred into the CWT or to render the fuel vapor in the tank nonflammable."

Accident investigation: