2003 Gréolières-les-Neiges Robinson R44 Clipper accident (F-GYDH)

Accident overview and flight details On 11 January 2003, a Robinson R44 Clipper helicopter with the registration F-GYDH crashed at Gréolières-les-Neiges in the Alpes-Maritimes department of France. The accident occurred at 12:55 UTC, which corresponds to 13:55 local time. The aircraft was operating a private scenic flight in the hinterland of Nice. It departed from Cannes-Mandelieu aerodrome with three people on board: the pilot and two passengers. Witnesses reported seeing the helicopter fly from west to east along a snow-covered ridge before passing over the ski slopes of the Gréolières-les-Neiges resort. Shortly afterward, they heard a clattering noise and observed the helicopter fall and crash. ## Casualties and aircraft condition All three occupants were killed in the accident: one crew member and two passengers. The helicopter struck a prominent rock on the north slope of Mont Cheiron, within the area of the winter sports station. The impact caused the aircraft to break into two main parts. The cabin, main rotor, and engine remained near the rock, while the tail boom and anti-torque rotor came to rest ten meters away in a west-east direction. The limited debris field indicated that the helicopter had a nearly vertical trajectory at the moment of impact. ## Investigation findings The investigation was conducted by the Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile (BEA). Laboratory examinations of the wreckage showed that all damage was consistent with the violent impact with the ground. Analysis of the transmission chain and main rotor indicated that the engine was producing low power at the time of impact. Tests confirmed that the engine governor and the low rotor RPM alarm electronic box were functioning correctly. The low RPM warning light filament showed that the light was probably off at impact. The rotor tachometer circuit breaker was found in the off position, although video evidence suggested the tachometer was functioning normally, leading investigators to conclude it likely disengaged during the impact. The collective pitch sensor used to inhibit the low RPM alarm on the ground was destroyed, and its operational status could not be determined. ## Meteorological and operational context Meteorological data estimated for the site indicated a wind from 060° at 10 knots, visibility of 10 km, few clouds at 3,600 feet, scattered clouds at 9,000 and 20,000 feet, a temperature of 0°C, and a QNH of 1012 hPa. Measurements from the Caussols automatic weather station at 1,350 meters recorded a wind from 060° at 12 knots, a temperature of +2°C, a dew point of -7°C, and 53% humidity. The helicopter was equipped with a Lycoming O-540 F1 B5 six-cylinder piston engine with a carburetor, capable of developing a maximum power of 225 horsepower. At the time of the accident, the aircraft was operating at altitudes between 4,300 and 5,300 feet with outside temperatures between -2°C and +2°C, conditions under which the maximum allowable manifold pressure was approximately 22.5 inches of mercury.