TWA Flight 800 - Conclusions

Conclusions

The NTSB investigation ended with the adoption of its final report on August 23, 2000. In it the Board determined that the probable cause of the TWA 800 accident was:

explosion of the center wing fuel tank (CWT), resulting from ignition of the inflammable 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.

In addition to the probable cause, the NTSB found the following contributing factors to the accident:

• The design and certification concept that fuel tank explosions could be prevented solely by precluding all ignition sources
• The 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 tank vapor non-combustible.

During the course of its investigation, and in its final report, the NTSB issued fifteen safety recommendations, mostly covering fuel tank and wiring-related issues. Among the recommendations was that significant consideration should be given to the development of modifications such as nitrogen-inerting systems for new airplane designs and, where feasible, for existing airplanes.