leakage may have been a result of the decrease in cabin pressure. A malfunction in the electrical circuits was also considered as an ignition source, but could not be confirmed because of the design of the aircraft's electrical systems and protection devices. Terrorism was ruled out as a cause, as there was no evidence that incendiary devices were used. See also Aviation safety List of accidents and incidents involving commercial aircraft References External links Airliner accidents and incidents caused by in-flight fires Pakistan International Airlines accidents and incidents Accidents and incidents involving the Boeing 707 Aviation accidents and incidents in Saudi Arabia Aviation accidents and incidents in 1979 November 1979 events in Asia 1979 in Saudi Arabia 1979 in Pakistan 1979 disasters in Pakistan 1979 disasters in Saudi Arabia