What happened
Following standard pre-takeoff procedures, the co-pilot taxied the aircraft to the end of a 5,010-foot runway. The aircraft was positioned slightly right of the runway centerline with the tail wheel locked. As the takeoff roll commenced and the tail lifted, the co-pilot applied forward pressure to the control column. During the acceleration, the aircraft began oscillating between left and right swerves due to a series of over-corrections.
During these maneuvers, the crew observed an initial five-inch drop in manifold pressure in the left engine. As the aircraft reached roughly 80 knots, it veered toward the left again. The captain assumed control after observing a further 25-inch drop in the left engine's manifold pressure. Despite closing both throttles immediately, the pilot could not arrest the turn. The aircraft entered a skid, causing the main landing gear to collapse and rupturing the right wing fuel tank. The plane came to a stop on the sodded area off the runway, facing the opposite direction of its initial takeoff heading. A fire broke out near the right engine nacelle shortly after the impact. All passengers evacuated the cabin in an orderly fashion under the guidance of the flight attendant, while the pilots exited through the cockpit windows.
Findings
- The primary factor was the loss of directional control during the takeoff roll.
- The aircraft experienced a violent groundloop that led to the gear collapse and fuel tank rupture.
- While there was no definitive evidence of structural or control failure, investigators noted the possibility of a malfunction within the pedal assembly.
- Post-accident testing showed that both engines were operating normally.