DC-10 Certification: The draft Failure Mode and Effects Analysis was modified by Douglas to minimize design deficiency. A ground test failure in May 1970 was blamed on human error. In retrospect, poor design was downplayed as a root cause. During November 1970, internal memos between Convair and Douglas discussed proposed fixes to the cargo door problem but none was implemented. The Federal Aviation Administration certified the DC-10 on July 29, 1971, with an unsolved design deficiency. In March 3, 1974, a Turkish Airline DC-10 crashed in France killing all 346 people aboard. The cause of the accident was faulty latches on the cargo door which allowed the differential pressure in the cabin at 11,500 feet altitude to force the door to swing open to the outside of the plane where it was ripped open off its hinges by the air stream. After this accident, the entire DC-10 fleet was finally grounded and the cargo door locking system was redesigned and the problem eliminated.