History of the Flight
The pilot, accompanied by a friend, departed from Dijon-Darois aerodrome at approximately 14:30 for a local flight of about 30 minutes, overflying Montculot château and the Roche d'Anse rocky spur. After returning, the pilot took off again at 15:00 with another friend for a similar flight. About 15 minutes after takeoff, near the Roche d'Anse spur, the pilot lost yaw control of the helicopter. A ground witness observed the helicopter spinning multiple times as it descended toward the forest and then disappeared into the trees. Radar data indicated a turn to the north-west with decreasing ground speed in the final seconds, but it could not determine whether the loss of control preceded or followed this change in direction.
Wreckage and Site
The wreckage came to rest at an altitude of 1,608 ft on a wooded hillside, 70 m from the Roche d'Anse spur (1,745 ft). The helicopter was resting on its damaged skids, with the tail boom wedged between two trees. Damage to the main rotor blades and the small hole in the vegetation indicated that the helicopter fell flat through the tree canopy with near-zero horizontal speed. The tail rotor blades failed near their attachment points; one blade tip was missing. The tailplane (horizontal and vertical stabilizers) was found ruptured near the wreckage. Examination of fractures and distortions showed that all ruptures resulted from impact with vegetation or the ground. No technical failure was identified.
Pilot Information
The 75-year-old pilot held a Private Pilot Licence for helicopters (PPL(H)) issued in 2000, with 200 flight hours on the Robinson R22, R44, and Bell 206, including 135 hours as pilot-in-command. He had flown only the R22 recently, logging about 7 hours in the previous three months, including a flight with an instructor to renew his R22 type rating. He also held a Private Pilot Licence for aeroplanes with nearly 700 hours, as well as microlight licences. The pilot reported no clear memory of the accident. He recalled a gust of wind or severe turbulence while climbing toward the château, which he associated with a sudden loss of tail rotor effectiveness. He attempted to recover using left and right rudder pedal inputs and lowering the collective pitch control, as taught in loss-of-tail-rotor-effectiveness procedures, but was unsuccessful. The helicopter continued to yaw, and the descent lasted less than 30 seconds before impact. The pilot and passenger exited the wreckage and alerted emergency services. The pilot stated that the engine operated normally, no warnings activated, and he believed no mechanical issue occurred.
Passenger Statement
The passenger, a student pilot, said they were flying around the rocky spur at about 200 m height when the helicopter began rotating. He recalled a right-hand rotation but was not certain. He observed the pilot making extensive cyclic inputs, causing the helicopter to pitch up and down while spinning. His feet were under the seat, away from the rudder pedals, and he did not interfere with the controls.
Meteorological Information
Météo-France estimated the wind at the accident time as west-northwesterly at 10 to 15 kt, relatively laminar. Convective turbulence was generated by cumulus clouds at 5,000 ft altitude. The local aerology may have been affected by hills and varied vegetation along the flight path. Temperature was approximately 21°C.
Helicopter Information
The helicopter, registration F-GFHA, was a Robinson R22 Beta powered by a Lycoming O-320-B2C engine. According to the flight manual, the helicopter had not reached the power limit for hovering out of ground effect under the prevailing conditions. The main rotor rotates counterclockwise (American design), with a conventional tail rotor. The flight manual includes two emergency procedures for loss of tail rotor power: in forward flight, enter autorotation and maintain 70 kt; in hover, lower the collective pitch control quickly. The manufacturer notes that at speeds above 60-70 kt, the vertical stabilizer provides yaw stabilization, reducing the need for tail rotor input.
Conclusions
The helicopter lost yaw control while flying near a rocky spur. No technical failure was identified. The investigation could not determine the exact cause of the loss of control.