Last night, as per my typical Friday night chill-out routine, I watched an episode of the popular television series Air Crash Investigation. Yes I know this is not really what normal people do with their Friday nights, but who said avgeeks are normal people. This week’s episode centered on Turkish Airlines Flight 981 and American Airlines Flight 96, both of which were operated by the McDonnell Douglas DC-10.

At the time of the incidents (which were only 2 years apart), the DC-10 was McDonnell Douglas’ state-of-the-art widebody airliner and a pretty big gamble. They had sunk a lot of money into the airliner and really depended on its success. Unfortunately, it turns out that the DC-10 had a fatal flaw in the design of its cargo door that was first seen American Airlines Flight 96 and later on Turkish Airlines Flight 981. This ultimately led to the deaths of 346 passengers and crew on the Turkish Airlines flight, and also crippled the safety record of the aircraft.

Most aircraft doors (including cargo doors) are designed to open inward. This ensures a better seal as the door would be pressed into the aircraft frame when the aircraft cabin is pressurized at high altitudes. The DC-10’s cargo door, on the other hand, was designed to open outward in order to increase the amount of space in the baggage compartment. The only problem with this design is that the door would be under a lot stress while the aircraft is in flight as cabin pressure would constantly be pushing on the door and trying to force it open. To compensate, McDonnell Douglas opted to add a few extra clamps to strengthen the locking mechanism. The design of the locking mechanism also made it so that it could easily be improperly secured without the knowledge of the baggage handler or the flight crew.

The issue first appeared onboard the American Airlines flight, which was climbing out of Detroit Airport when the cargo door blew off the airplane and created a gaping hole at the back of the cabin. In the process, the debris also ruptured hydraulic lines and thus jammed the rudder to the right and hindered most of the control surfaces. Captain McCormick still managed to get the aircraft back to the airport for a landing. There were no fatalities. Not even Sully and his Hudson stunt could match the amazing flying by Captain McCormick on that day.

And so the NTSB did what they do best and found that the cargo door locking error was what had caused the incident. As they don’t have much authority, all they could do was advise airlines to remind baggage handlers to make sure that they secure the cargo doors on the DC-10 properly. Two years later, Turkish Airlines Flight 981 went down in northern France, killing all 346 on board. The NTSB came and did their thing again, only to find that this crash was also caused by the cargo door issue that affected American Airlines Flight 96. This time around however, the explosive force of the failed cargo door ruptured all hydraulics lines. Thus, the pilots had no control of the airplane and couldn’t recover from the dive that sent the aircraft plummeting towards the ground. It was only after this incident that the FAA grounded the DC-10 until major improvements were made. It was soon discovered that McDonnell Douglas knew about the cargo door issue in the development phases of the aircraft, and chose not to address the issue. They were soon flooded with lawsuits from the families of passengers killed by the crash, and ended up paying millions in compensation. All this could’ve been prevented if McDonnell Douglas had simply spent the money to fix the DC-10’s cargo door.