What happened
During a flight intended to transport bypass mail from Nome to Gambell, Alaska, the pilot experienced a sudden loss of control during the takeoff roll. According to the pilot, the initial takeoff run proceeded normally until the rotation maneuver was initiated. Upon lifting the nose, the aircraft experienced an uncommanded pitch-up motion. The pilot attempted to counteract this by applying maximum forward pressure on the control yoke and adjusting the pitch trim to a nose-down position.
As the aircraft continued its ascent, it rolled toward the left. The pilot utilized the rudder pedals to attempt to level the wings, but the aircraft ultimately impacted the ground. There were no fatalities reported in the accident.
Findings
Investigations involving the FAA, the operator, and the postal service revealed that the aircraft was operating above its permitted weight limits. At the time of departure, the aircraft's weight was recorded at 10,114 pounds, which exceeded the certified maximum gross weight of 10,100 pounds.
Furthermore, a review of the weight and balance data indicated that the center of gravity was positioned at 121.9 inches, which was outside the manufacturer's specified range of 113 to 120.5 inches. An examination of the wreckage confirmed that the elevator trim indicator was set to a full nose-up position, contributing to the unstable pitch behavior during rotation.