What happened
A flight intended to transport 24 parachutists to an altitude of 12,500 feet ended in a fatal accident during a mass jump operation. The aircraft was configured for cargo use rather than passenger seating, featuring a single jump seat and 2ally 24 seat belts positioned on the floor. For the purpose of facilitating exits, the cabin door had been removed, and unapproved external steps and handholds had been installed near the opening.
During the standard jump-run procedure, the aircraft was slowed to between 95 and 100 knots, with landing gear extended, flaps set, and power reduced on the left engine. As the aircraft approached the drop zone, several jumpers moved toward the doorway or outside the airframe. While the initial jumpers were unaware of any mechanical issues, they observed the plane enter a steep bank, roll over, and begin a nose-down spiral. Although 16 jumpers successfully exited the aircraft, three fatalities occurred when individuals struck the stabilizer during the descent. The aircraft subsequently impacted the ground in a near-vertical trajectory.
Findings
Investigations into the accident identified several critical contributing factors regarding the aircraft's configuration and flight state. The center of gravity was found to be positioned behind the aft limit for both takeoff and the jump mission. Additionally, the elevator trim actuator was set to a position indicating full nose-up trim. The loss of control was further exacerbated by an inadvertent stall following a reduction in airspeed.