Silvana

The aircraft was on a sport parachute flight to carry 24 parachutists to 12,500' over a drop zone (dz) for a mass jump. It was in a cargo configuration with no passenger seats, but it had one jump seat. There were 24 seat belts on the floor of the cargo area. Also, the cabin door had been removed and an unapproved step and 4 handholds were installed outside and forward of the cabin door for parachutists. The usual jump-run procedure was for the aircraft to be slowed to 95 to 100 knots, extend the gear and approach flaps and reduce power on the left engine. The jumpers remained in position without using seat belts until approaching the dz, then two moved outside the aircraft while others moved close to the doorway. The first jumpers were unaware of any problem, but saw the aircraft enter a steep bank, roll over and spiral nose down. 16 jumpers exited the aircraft, but three hit the stabilizer. The aircraft crashed in a near vertical descent. Investigation revealed the cg was behind the aft limit for takeoff and the jump. The elevator trim actuator was found in a position for full nose-up trim.