Turkish Airlines Flight 981 crashed in March 1974, marking the world’s deadliest single-aircraft accident at the time. The DC-10 saw the left cargo door tear off while flying over France, causing a critical cockpit malfunction and the aircraft to crash. Here is what happened.
The accident occurred on March 3, 1974 aboard one of Turkish Airlines’ Douglas DC-10s. TK981 was supposed to fly from Istanbul to London Heathrow with a stop at Orly Airport in Paris. The first leg from IST to ORY went smoothly, the flight lasting four hours.
While the ORY-LHR leg did not usually attract many passengers, the ongoing British European strike meant that the economy cabin was full on that fateful flight. The flight took off at 12:32 local time, but things went wrong within minutes of the flight. While flying over Meaux, about 50 kilometers away, the DC-10 lost its rear cargo door.
The loss of the rear left cargo door made a huge difference in overpressure with the cabin directly above it. This part was torn from the plane along with the six passengers who were sitting there. However, the loss of the doors caused the pilots to lose access to critical parts of the aircraft, including the rudder, elevator and engine two.
The loss of control depressed the nose by 20 degrees and caused an increase in speed. Attempts to pull the nose up and level out failed, causing the DC-10 to crash into the Ermenonville Forest just 77 seconds after the cargo door was ripped off. The crash site meant that the accident is also known as the Ermenonville disaster.
The plane crashed at a speed of 783 km/h and broke the plane into thousands of pieces. This made it difficult to identify victims and collect evidence due to the vastness of the wreckage. In all, all 346 on board were killed, comprising 11 crew and 335 passengers (including six who died after the cabin ruptured).
The investigation centered around the cargo door and why it came off. It quickly became clear that the cause was a design flaw and the failure of the ground engineers to ensure that the doors were in the locked position before take off. In particular, the hinge of the DC-10’s rear cargo door did not move into the correct position and the locking pins were not in place. This meant that when they passed 11,000 feet, the latches released and the doors opened.
Turkish Airlines had no engineer on the ground at Orly that day and had baggage handler Mohammed Mahmoudi close the door. After following the basic procedure, the cabin warning light went off and he assumed the door had closed successfully. In fact, the locking pins were not engaged and the cockpit light was a false indicator.
After, The investigation placed blame on Turkish Airlines and Douglas himself, as both were to blame for different parts of the crisis. The airline failed to place an engineer on the ground and reportedly rushed the training process for the DC-10. However, McDonnell-Douglas was aware of the deficiencies in the door design and the NTSB directive after a similar incident was not implemented.
TK981 became the deadliest single-aircraft crash in more than a decade, until the crash of Japan Airlines Flight 123. As a result, several design changes were made to the DC-10 to prevent such crashes, and review of the design process was renewed.