What happened
The pilots reported that the en route portion of the flight and the subsequent approach to landing were routine. After the aircraft touched down on the runway, it settled normally to the ground. However, as this occurred, the left wing dropped abruptly. This sudden movement caused the aircraft to veer off the left side of the runway.
The investigation
A post-accident examination of the wreckage was conducted to determine the mechanical cause of the incident. The inspection revealed that the left main landing gear assembly had failed. The failure was attributed to stress corrosion within the gear components. Maintenance records indicated that the aircraft had accumulated 495 hours of total time. The most recent annual inspection had taken place in June 1988, with only 45 hours logged since that service.
Findings
The primary factor leading to the runway excursion was the structural failure of the landing gear. The stress corrosion compromised the integrity of the left main gear assembly, preventing it from supporting the aircraft's weight properly upon touchdown. This mechanical failure directly resulted in the left wing dropping and the subsequent loss of directional control.