What happened
On March 3, 1974, a scheduled international flight operated by Turkish Airlines departed from Istanbul Yeşilköy Airport with London Heathrow as its final destination. The aircraft, identified as TC-JAV, was a McDonnell Douglas DC-10 wide-body jet. Following the departure from Istanbul, the flight made an intermediate stop at Orly Airport in Paris.
Shortly after taking off from Orly, the aircraft experienced a catastrophic structural failure. The rear cargo door blew out due to a design flaw in the latching mechanism. This event caused decompression and subsequently led to the collapse of the passenger cabin floor above the cargo hold. The loss of hydraulic pressure resulted in the failure of critical flight controls, including the elevators and rudder. Unable to maintain control, the aircraft entered an uncontrolled descent and crashed into the Ermenonville Forest, located approximately 40 kilometers northeast of Paris.
Investigation
The subsequent inquiry focused heavily on the mechanics of the cargo door failure and the structural integrity of the cabin floor. Investigators determined that the primary issue lay in the design of the rear cargo door system. The latches were not interlocked with the pressure differential, meaning they could be released while the aircraft was still pressurized.
Furthermore, the investigation highlighted that the cabin floor above the cargo hold was not designed to bear the weight of passengers and luggage if it detached. When the door opened in flight, the pressure difference ripped the floor away, taking with it the hydraulic lines and control cables necessary for pitch and yaw control. This combination of factors rendered the aircraft uncontrollable.
Findings
The disaster resulted in the deaths of all 335 passengers and 11 crew members on board, making it one of the deadliest aviation accidents at the time. The findings established that the root cause was the inadequate design of the cargo door latching system, which allowed for accidental opening during flight. Additionally, the lack of structural reinforcement in the cabin floor above the cargo hold exacerbated the loss of control. These revelations led to significant changes in aircraft design standards globally, particularly regarding cargo door safety and cabin floor strength.