Investigation Summary
The investigation was one of the most complex in aviation history, involving the physical reconstruction of the aircraft wreckage recovered from the ocean floor. Initial theories included a missile strike or a bomb, fueled by hundreds of eyewitness accounts describing a streak of light ascending toward the aircraft. The NTSB conducted an exhaustive analysis of these reports, eventually concluding that witnesses had seen the burning aircraft during its post-explosion climb and breakup rather than an external projectile. The focus shifted to the Center Wing Tank (CWT), which was nearly empty but contained a volatile mix of fuel vapor and air. On the day of the flight, the aircraft sat on the tarmac for over two hours with the air conditioning packs running directly beneath the CWT, heating the fuel to temperatures well above its flash point. The NTSB determined that a high-voltage surge from a short circuit in the fuel quantity indication system (FQIS) likely provided the ignition source.
Final Conclusions
The probable cause was an explosion of the center wing fuel tank, 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 the most likely source was a short circuit outside of the tank that allowed excessive voltage to enter it through electrical wiring associated with the fuel quantity indication system.
Video Analysis
The Tragic Story of TWA Flight 800 — A detailed look at the investigation into the explosion of TWA 800 and the scientific efforts to determine the cause.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Occupied the left front seat.
Captain/Check Airman
Occupied the right front seat.
Systems & Failure Modes
Center Wing Tank (CWT)
A large fuel tank located in the fuselage between the wings, susceptible to heating from nearby systems.
Fuel Quantity Indication System (FQIS)
The electrical system used to measure fuel levels; suspected of carrying the ignition spark into the tank.
Inerting System
A safety system (not present on TWA 800) designed to replace oxygen in fuel tanks with non-flammable gas.
Interesting Facts
- 01The aircraft had been in service for 25 years with over 93,000 flight hours.
- 02The Center Wing Tank (CWT) contained only about 50 gallons of fuel at the time of the explosion.
- 03The air conditioning packs located under the CWT were running during the ground delay, heating the fuel.
- 04Over 95% of the aircraft wreckage was recovered and reconstructed in a hangar.
- 05The FBI conducted a parallel criminal investigation but found no evidence of a terrorist act.
- 06The NTSB concluded the streak of light reported by witnesses was the aircraft itself in a crippled, burning climb after the initial explosion.
- 07Radar data showed no evidence of a missile or projectile approaching the aircraft prior to the explosion.
Safety Actions & Advisories
Fuel Tank Flammability Reduction
The FAA mandated the installation of Nitrogen Generation Systems (NGS) on new and existing large transport aircraft to 'inert' fuel tanks.
Wiring Inspections
New requirements were established for the inspection and maintenance of aging aircraft electrical wiring systems (EWIS).
Design Changes
Manufacturers were required to reduce heat transfer from heat sources (like AC packs) to fuel tanks.
Location
APPROXIMATE AREA ONLY · This position predates coordinate provenance tracking. Treat it as an approximate marker for the area, not the accident site. No map is shown, because a marker here would imply a precision the record does not have.
Reported location: East Moriches, New York