What happened
Approximately one hour after its scheduled departure, the pilot requested taxi clearance from air traffic control. Shortly after receiving clearance, the aircraft began its takeoff roll. An observer noted that the aircraft did not perform a standard engine run-up before proceeding onto the runway. The aircraft achieved liftoff within approximately 100 yards of the start of the takeoff roll, but immediately entered a sharp left bank. This bank intensified, leading to a descent that resulted in a ground impact.
Findings
An investigation of the wreckage identified that the pilot's four-point harness was unfastened. Crucially, investigators discovered that a portion of the cockpit flight control lock was still engaged on the control column. Although the pre-takeoff checklist required the pilot to verify that flight controls were unlocked and had full travel, this step was not successfully completed.
Technical analysis revealed that the aircraft type was susceptible to such an event because the control lock design could potentially allow the plane to become airborne even if the lock remained installed. While service bulletins from the manufacturer had previously addressed this risk, and Transport Canada had issued an airworthiness directive in 1990, the FAA had not yet implemented a similar mandatory directive at the time of the accident. The failure to remove the control lock was the primary factor in the loss of control.