Turkish Airlines Flight 981 was a flight that flew on a Ankara-Charles de Gaulle International Airport (near Paris) - London Heathrow Airport (London) route.
The Ermenonville air disaster was the high-speed crash of a DC-10 on this route into a forest at Ermenonville, France. On 3 March 1974, the flight came down just minutes after take-off on the Paris-London leg. A defective latch on the cargo door caused it to open in flight, resulting in an explosive decompression. The decompression caused the cabin floor near the door to fail, sucking six passengers out of the plane and severing the control cables leading to the tail surfaces. With elevator control lost, the plane dived into the ground at 430 knots.
The plane left a trail over a kilometer long through the forest, and few pieces larger than a meter were left. All 346 people aboard were killed in the accident, a large number of these were English rugby fans who had transfered to the plane after their own flight had been canceled due to a strike in London. It was the worst air disaster to date.
The hatch of the DC-10 is an interesting study in human factors, interface design and engineering responsibility. The control cables for the rear control surfaces of the DC-10 are routed around the hatch, so a failure of the hatch could lead to the disruption of the controls. To make matters worse, Douglas chose a new latch design to close it. If the hatch were to fail for any reason, there was a very high probability the plane would be lost. This possibility was first discovered in 1969, and actually occurred in 1970 in a ground test. Nevertheless nothing was done to change the design, as any such changes would be made out-of-pocket by the fuselage main-contractor, Convair.
The first hatch related accident occurred in June 1972 on a flight from Detroit to Toronto, when the hatch was closed improperly by ground crew unfamiliar with the new latch design. The hatch blew off at 12,000ft, destroying the rudder control completely and damaging the elevator controls, but quick thinking on the part of the pilot and the help of a general aviation pilot in the cabin allowed the plane to land with no injuries. The NTSB made several recommendations in the wake of this first accident, but the FAA didn't order any of them made, instead Convair agreed to carry them out voluntarily.
However, these modifications were never actually carried out. Ship 29, the one that crashed at Ermenonville, had been certified by three inspectors at Convair's Long Beach plant as having been modified, but nothing had actually been done. All of this came out in the post-crash investigation, leading to a number of changes in the FAA's reporting chain.