What happened
On April 8, 2000, a Pilatus PC-6 "Turbo Porter" was performing parachute deployment flights near Breitscheid. During the final approach to runway 07, the aircraft entered a steep descent. Witnesses observed parts of the aircraft detaching and a person trailing from the rear of the plane before falling to the ground. The aircraft subsequently struck a field in a near-vertical attitude and caught fire. Both occupants, the pilot and a second crew member, were killed.
The investigation
The BFU investigation focused on the sequence of events leading to the loss of control. Investigators found the wreckage of the aircraft near the approach path, while the body of the passenger was located approximately 35 and 50 meters away from the main wreckage. Debris from the aircraft's stabilizer and parts of a parachute system were also recovered near the passenger.
Evidence showed that the passenger was wearing a sport parachute system equipped with a "Student-Cypres" electronic reserve activation device. The investigation determined that the device functioned according to its design: it triggered the reserve parachute at an altitude of approximately 280 meters because the aircraft's descent rate had exceeded 13 m/s. The investigation also examined whether the passenger had manually deployed the parachute, but forensic evidence indicated the deployment was automated, which subsequently pulled the passenger out of the aircraft through the open door.
Findings
- The primary cause of the accident was the unintended activation of the reserve parachute deployment device during the landing approach.
- The deployment of the parachute caused the parachute to become entangled with the right side of the horizontal stabilizer, leading to significant structural damage and the loss of the aerodynamic trim horn.
- The drag from the entangled parachute and the person caused a rapid loss of airspeed and rendered the aircraft uncontrollable.
- The pilot failed to ensure that the electronic activation device was switched off prior to the flight, despite the known risks of using such a device during a descent profile that meets the activation criteria.
- The passenger was wearing a sport parachute system rather than a dedicated rescue parachute, and the crew did not verify the status of the activation device before flight.