Turkish Airlines Flight 981 (TK981/THY981) was a scheduled flight from Istanbul Yeşilköy Airport to London Heathrow Airport, with an intermediate stop at Orly Airport in Paris. On 3 March 1974, the McDonnell Douglas DC-10 operating the flight crashed into the Ermenonville Forest, outside Paris, killing all 346 people on board. The crash was also known as the Ermenonville air disaster. Flight 981 was the deadliest plane crash in aviation history until 27 March 1977, when 583 people perished in the collision of two Boeing 747s in Tenerife. It remained the deadliest single-aircraft accident until the crash of Japan Airlines Flight 123 on 12 August 1985, and the deadliest aviation accident without survivors until the Charkhi Dadri mid-air collision on 12 November 1996. It remains the deadliest single-aircraft accident without survivors, the first fatal and deadliest crash involving the McDonnell Douglas DC-10, the sixth deadliest aviation disaster altogether (including 9/11), and the deadliest aviation accident to occur in France. It is also the deadliest aviation incident that did not involve a Boeing 747 (not including 9/11). The crash occurred when an incorrectly secured cargo door at the rear of the plane burst open and broke off, causing an explosive decompression that severed critical cables necessary to control the aircraft. To maximize the working space within the cargo hold, the cargo doors opened outwards, making them vulnerable to being forced open at high altitudes under normal in-flight pressure. To prevent this, a special latching system was used that locked shut under pressure when properly closed. To ensure the latches were properly positioned, a handle on the outside of the door pressed small metal pins into the latches; if the latches were in an improper location the pins would not align and the handle would not close. In previous service, notably an incident that occurred on American Airlines Flight 96 in 1972, it had been noticed that it was possible to close the handle on DC-10 cargo doors despite the latches being in the wrong position.