PIA Flight 740

Pakistan International Airlines Flight PK740 was a Boeing 707-340C that crashed after takeoff from Jeddah International Airport on 26 November 1979. Flight PK740 departed Jeddah at 01:29 for a flight to Karachi after Pilgramage. The aircraft was climbing to FL370 (37,000 feet) when, at 01:47, a stewardess reported a fire near the aft cabin passenger door. The crew started a descent from FL300 and were cleared to descend to 4,000 feet. Following a mayday call at 02:03, nothing more was heard from the flight. The aircraft crashed in a level rocky area at an elevation of 3000 feet and burst into flames. All 156 aboard were killed. An in-flight fire in the cabin area, through its intensity and rapid extension, resulted in panic among the passengers and smoke in the cockpit, eventually incapacitating the flight crew. The cause of the cabin fire was not determined. It was considered that the origin of the cabin fire could have been a leaking gasoline or kerosene stove carried aboard by Hajj pilgrim passengers. Pressure differential could have caused a poorly sealed gasket to leak fuel. A second possibility is an electrical fire, but the rapid extension of the fire was considered difficult to explain because of the electrical circuit protection devices of the Boeing 707. Sabotage was considered as another possibility, but no evidence of an incendiary device was found. Another possibility was that the plane had entered a no-fly zone, where auto missiles could have shot from the ground blasting the plane.

• http://en.wikipedia.org/wiki/PIA Flight 740