Pakistan International Airlines Flight 740

On 26 November 1979, Pakistan International Airlines Flight 740, a Boeing 707 operating a scheduled international passenger flight from Kano, Nigeria, to Karachi, Pakistan, via Jeddah, Saudi Arabia, crashed near Taif after attempting to return to Jeddah International Airport following an in-flight fire, killing all 145 passengers and 11 crew members.

Around eighteen minutes after taking off from Jeddah, a flight attendant reported to the flight crew that a fire had started in the aft section of the aircraft. The flight crew were given clearance by air traffic control to return, and were ordered to start descending to 4000 ft. The crew levelled off at 11000 ft to account for minimum safe altitudes; however, due to the rapidly spreading fire in addition to smoke likely incapacitating the crew, control of the aircraft was lost, and it subsequently crashed.

Despite theories that sabotage or an electrical issue had caused the crash, which were discounted due to a lack of evidence, the cause of the fire could not be conclusively determined. The Saudi-led investigation concluded that one or multiple leaking gasoline or kerosene stoves carried by Muslim pilgrim passengers had likely ignited. It was probable that an increasing pressure differential and improperly sealed gaskets led to leaks from the stoves which were then ignited either by a spark or a cigarette.

Accident

On 26 November 1979, Pakistan International Airlines Flight 740 was operating a scheduled passenger flight from Kano, Nigeria, to Jinnah International Airport, Karachi, Pakistan, via Jeddah International Airport, Jeddah, Saudi Arabia. At 01:29 local time, the aircraft took off from Jeddah International Airport en route to Karachi in clear weather and nighttime conditions. At 01:47, while still climbing, a flight attendant went into the cockpit and reported a "large fire" and "a lot of smoke" in the rear section of the aircraft. The flight engineer was sent by the captain with a fire extinguisher to assess the situation; when he reported back to the cockpit, he stated that the fire had started near the door while the flight attendant instead suggested that it started in parallel in the toilet. He also stated that attempts to extinguish the fire had failed. When asked by the captain to return to extinguish the fire, he stated that it was "not possible to go back" as there was "too much fire", and at the same time, passengers were also crowded in the isle.

The captain did not initially turn back towards Jeddah, continuing to climb to their cruise altitude of 37000 ft. Deciding to turn back, at 01:51, the flight crew reported the fire to air traffic control (ATC) and requested clearance to return to Jeddah: "Jeddah Pakistan 740 at 290 position 123 DME. We would like to return back to Jeddah due to smoke in the aircraft - fire - electrical supposedly." The air traffic controller responded with, "Do whatever you like, sir", and the crew started their descent from 30000 ft. At 01:57, the crew asked ATC, "Jeddah, Pakistan 740, can you tell us what height we can descend to safely?", with ATC replying "Cleared to descend to 4,000 feet." The captain replied, "Roger, 4,000", and asked his first officer verify the area's minimum safe altitude (MSA), with the first officer replying, "It's about 11,000 feet." The descent clearance issued by the ATC failed to take into account the area's MSA, although the investigation noted that this did not contribute to the accident as the flight crew recognised the error and levelled off at 11000 ft.

At 02:00, the first officer stated, "We are getting flames inside the

back, you want to get down faster." At 02:01, an emergency descent was started; the first officer told ATC, "We're making an emergency descent, request radar assistance for landing", to which the ATC granted. At 02:03, the crew declared an emergency; this was their final transmission. Twenty seconds after the transmission, the flight could be seen on the controller's radar as being 65 mi away from Jeddah at an altitude of 19000 ft, before losing radar contact. As the fire continued to rapidly grow, despite donning their oxygen masks, the smoke likely incapacitated the pilots. Travelling south-south-east, the aircraft lost control and entered an 8000 ft dive.

At 02:04:15, the aircraft crashed into a rocky desert plateau at an elevation of around 3000 ft, 90 mi east of Jeddah, near Taif, killing all 156 passengers and crew. The crash, witnessed by the crew of a BAC One-Eleven around 30 mi away, resulted in an explosion and the disintegration of the aircraft. The wreckage of the aircraft was spread over a 3 mi radius, 3800 ft in length and 1100 ft in width.

Rescue teams were quickly deployed to search for the aircraft in a difficult-to-access area.

Three Saudi Air Force aircraft carrying rescue teams were deployed to the crash site. Upon arrival, no survivors could be found. Authorities in Saudi Arabia first addressed the crash after 18 hours. The crash was, at the time, Saudi Arabia's deadliest aviation accident.