Flight Sequence
On 20 May 2001, a Pilatus Porter PC-6/B2-H4, registration HB-FKF, operated by Swissboogie Parapro SA, departed Bienne-Kappelen at 14:31 local time for parachute drop flights at Neuchâtel. After completing the last drop over Neuchâtel at 18:20, the aircraft was positioned on the helicopter area near holding point 23 with the engine running. The pilot waited for an aircraft that had announced in the landing circuit for Runway 05 to complete its approach. Six parachutists were inside the Porter; the side door remained open as they intended to make one more jump over Bienne-Kappelen. The parachute instructor on board was also a Porter pilot.
Accident
As the pilot visually monitored the approaching aircraft, he observed it initiate a go-around near midfield, with an extremely nose-high attitude and poor directional control. The aircraft deviated from the runway axis and headed toward the Porter, creating a risk of collision. The Porter pilot decided to move his aircraft away to avoid a collision. Simultaneously, without informing the pilot, the parachute instructor, having also recognized the peril, ordered the parachutists to evacuate immediately. The two last individuals exiting were struck by the Porter's horizontal stabilizer as the aircraft began to taxi. One was transported to hospital; the other sustained minor injuries treated on site. The go-around aircraft passed directly over the Porter without causing damage and continued to an unknown destination.
Investigation
The pilot held a professional pilot license and wore an audio headset. The parachutist seated next to the pilot faced backward and was engaged in conversation; he did not hear the evacuation order or notice the exit. The ambient noise from the turbine and open door likely prevented the pilot from hearing the order. The radio service at the aerodrome had been discontinued shortly before the accident. The unknown aircraft was described by witnesses as a single-engine, fixed-gear, low-wing aircraft of light color. Extensive efforts to identify it—including inquiries to all Swiss aerodrome managers, radar data review, and analysis of the Geneva Information frequency recording—failed to yield results. Weather conditions were good: visibility over 10 km, northeasterly wind 4–6 m/s, temperature 21°C.
Cause
The accident is due to the fact that the parachutists, on the instruction of their instructor, left the aircraft because of a developing dangerous situation without informing the commander.