On July 18 , 2008 , the Secretary of Transportation visited the facility and announced a final rule designed to prevent accidents caused by fuel-tank explosions . The rule would require airlines to pump inert gas into the tanks , and will cover the centre-wing tank on all new passenger and cargo airliners , and passenger planes built in most of the 1990s , but not old cargo planes . The NTSB had first recommended such a rule just five months after the incident and 33 years after a similar recommendation issued by the Civil Aeronautics Board Bureau of Safety on December 17 , 1963 , nine days after the crash of Pan Am Flight 214
Pan Am Flight 214
Pan Am Flight 214
TWA Flight 800