Aircraft and Personnel
The accident involved a Piper J3C (registration HB-ONH), a high-wing, two-seat, single-engine aircraft built in 1944 and owned by the Club d'aviation des Placettes in Bex. The aircraft was equipped with a Continental-Rolls Royce O-200-A engine. The pilot, born in 1940, held a private pilot license issued on 25 July 1967 and had a total experience of 50 flight hours, including 25 hours as pilot-in-command. The passenger, born in 1945, had no aviation training.
The other aircraft involved was a Jodel DR-1050 M1 (HB-EEU), a low-wing, four-seat, single-engine aircraft built in 1965, also owned by the same club.
Accident Narrative
On 23 September 1967, at 1400 local time, the pilot invited his cousin for a flight. After pushing the Piper out of the hangar, the pilot seated the passenger in the rear seat and instructed him to press the pedals to brake. The pilot then primed the engine and manually rotated the propeller with the ignition off. Finally, he switched on the ignition and turned the propeller again. The engine started immediately, and the aircraft, with the passenger alone inside, began to roll forward toward the Jodel, which was correctly parked about 10 meters away. The pilot ran to the cockpit to stop the aircraft but could not prevent the Piper's metal propeller from striking the Jodel's right wing five times, causing serious damage.
Damage
- HB-ONH: Propeller slightly damaged.
- HB-EEU: Right wing seriously damaged, estimated at 20% of the aircraft's value.
Discussion
The official flight training manual recommends placing wheel chocks whenever the aircraft is on the parking area, especially if it lacks parking brakes. It also advises never to leave a passenger alone in the aircraft while hand-propping the engine, as the passenger may inadvertently cause the aircraft to move. The pilot did not follow these recommendations; the Piper was not equipped with parking brakes. Furthermore, the pilot's instructions to the passenger were incomplete: he did not explain that there are two sets of pedals per seat—one for the rudder and one for the brakes. The post-accident examination of the brakes showed they were in perfect working order, so the passenger most likely operated the rudder pedals instead of the brake pedals.
Conclusion
The investigation concluded that the accident was due to the pilot not taking the necessary precautions when starting the engine.