After weeks of investigation, French and U.S. officials believe that they have pinned down the cause of history's worst air disaster: the March 3 crash of a Turkish Airlines DC-10 just outside Paris that killed 346 people. An improperly sealed rear cargo door burst open in midair, and the loss of pressure in the cargo hold caused the plane's still-pressurized passenger cabin to buckle downward into the cargo compartment (see diagram). Passengers began spilling out of the plane, control cables to the rudder and stabilizers were fouled, and the plane crashed into a forest 13,000 ft. below.
But why did the cargo door come open? Investigators are not yet certain, but some suspect that it was possible for the door to appear fully locked when it was not. The events leading up to the crash, as disclosed in subsequent investigations that culminated in two days of congressional hearings last week, make a story almost as shocking as the disaster itself—and much more mysterious. It raises disturbing questions about the safety procedures at McDonnell Douglas, the maker of the DC-10, and about the practices of Government aviation safety regulators. The story in brief:
In June 1972, a cargo door blew out of an American Airlines DC-10 over Windsor, Ont., though the crew managed to land the plane safely. After investigation, the National Transportation Safety Board sent a number of recommendations to the Federal Aviation Administration for implementation as an "airworthiness directive." The directive, a drastic order with compliance supervised by the FAA, would have forced McDonnell Douglas and airlines flying the DC-10 to make certain design changes in the cargo door.
No Explanation. Executives at McDonnell Douglas, however, talked the FAA out of issuing the directive. Instead, the company was permitted to send out its own "service bulletin" recommending some less fundamental changes than the NTSB wanted. McDonnell Douglas was supposed to modify the doors of planes still on its assembly line, as the ill-fated Turkish Airlines DC-10 then was. Three inspectors signed records indicating that the modification was made on that plane—but Douglas Division President John Brizendine conceded last week that it was not. Why not? "We do not yet have an explanation," he said.
That is startling indeed. Until the crash, both the DC-10 and its maker had enjoyed high reputations. The DC-10 went into service in August 1971, and had a safety record above average for a relatively new aircraft. Thirty-one airlines now fly a total of 128 DC-10s; passengers praise the craft as spacious and quiet, and the FAA says that they are all safe (the agency finally issued its airworthiness directive about cargo doors on March 6, three days after the Turkish Airlines disaster).