Robinson R22 accident at Tourrettes (83) on 12 December 2016 (F-HALD)

Flight details and accident sequence On 12 December 2016, at about 14:00 local time, a Robinson R22 helicopter, registration F-HALD, operated by a flight school, was conducting a general aviation training flight. The aircraft carried an instructor and a student pilot. It departed from Cannes Mandelieu aerodrome (06), proceeded to Fayence aerodrome (83), and completed two circuit patterns. On the return leg, the instructor planned an autorotation exercise with engine restart over a field. The student performed the descent, after which the instructor took control while the student remained in a hands-off, transparent position. The instructor flared at approximately 30 to 40 feet and increased collective pitch before touchdown. The helicopter suddenly yawed sharply to the right by about 90 degrees. The instructor countered with rudder input and brought the aircraft back into alignment, but could not prevent ground contact. The skids struck the ground, the right skid more heavily; the helicopter rebounded, turned 90 degrees to the right, and came to rest in a nose-up attitude supported by the rear of the skids and the remaining portion of the tail boom, which had broken on impact. The helicopter was destroyed. ## Weather, crew experience, and technical findings Estimated weather at the accident site included light wind, CAVOK conditions, and a temperature of 16°C. The student pilot had 10 flight hours. The instructor had approximately 1,800 flight hours, including about 1,000 hours on type and 500 hours as an instructor. The instructor reported that after the yaw and his rudder input, he checked the parameters and saw engine and rotor RPM indications at 108%, above the normal operating value. He then reduced the throttle but was unable to regain control before ground contact. He stated that the engine stopped without any action on his part and did not mention any alarm. The flight manual recommends smooth throttle actions to avoid inadvertent engine shutdown. Examination of the wreckage did not reveal any malfunction likely to have contributed to the accident. Because the instructor questioned the power governor, a preliminary engine examination and a detailed examination of the power regulation system were performed. These confirmed good general condition and operation in accordance with manufacturer specifications. The governor regulates engine speed within the normal operating range of 80 to 115% and is activated or deactivated by the governor ON-OFF switch at the end of the right-hand collective pitch control. It does not limit speed in the event of under- or overspeeds generated by abrupt in-flight maneuvers. The flight manual specifies that the flare should be performed at 40 feet. ## Safety lessons and conclusion In general, the effectiveness of the flare is reduced in light wind. In addition, the instructor performed the flare at a height lower than that recommended in the flight manual. He then probably intensified his control inputs by requesting excessive engine power, which resulted in a yaw. The low altitude did not allow the pilot to regain control of the helicopter before the collision with the ground.