Accidents due to design deficiencies included TWA Flight 800 , where a 747-100 exploded in mid-air on July 17 , 1996 , probably due to sparking electricity wires inside the fuel tank ; this finding led the FAA to propose a rule requiring installation of an inerting system in the center fuel tank of most large aircraft that was adopted in July 2008 , after years of research into solutions . At the time , the new safety system was expected to cost US$ 100,000 to $ 450,000 per aircraft and weigh approximately . El Al Flight 1862 crashed after the fuse pins for an engine broke off shortly after take-off due to metal fatigue . Instead of dropping away from the wing , the engine knocked off the adjacent engine and damaged the wing
TWA Flight 800
TWA Flight 800
Boeing 747