Significant emphasis has been placed on fuel tank safety since the TWA flight 800 accident in July 1996. Since the accident, the Federal Aviation Administration (FAA) has issued numerous Airworthiness Directives to correct potential ignition sources in fuel tanks and has conducted research into methods that could eliminate or significantly reduce the exposure of transport airplanes to flammable vapors. The latter has been in response to new FAA policy which strives to eliminate or reduce the presence or consequences of flammable fuel tank vapor. This has included fuel tank inerting, which is commonly used by the military. However, the systems weight and resource requirements as well as perceived low dispatch reliability have indicated that fuel tank inerting would not be practical for application to transport airplanes. Additional FAA research is underway evaluating state of the art Hollow Fiber Membrane (HFM) gas separation technology. HFM technlogy could be used to generate on site Nitrogen Enriched Air (NEA) in a cost effective manner to inert fuel tanks while the aircraft is operating at the airport gate (Gound Based Inerting). HFM technology could also be used to develop on-aircraft inerting systems that are much lighter with greatly improved dispatch reliability.

The FAA has focused research to support two primary methods of fuel tank protection, both involving fuel tank inerting. Ground-based fuel tank inerting would involve some combination of fuel scrubbing and ullage washing with NEA while the airplane is on the ground if applied to all or most operating transport airplanes. It would only use ullage washing if applied to a limited number of airplanes, such as only those with heated center wing tanks (HCWTs). On aircraft fuel tank inerting would involve ullage washing during some or all aircraft operations with a system the generates NEA on the aircraft with the APU and/or engine bleed air.