What happened
On February 14, 2010, at approximately 15:20, an Eurocopter AS3orp 350 B helicopter, registration F-GFBB, was involved in a collision with vegetation during a mountain flight near Font d’Urle. The flight, a private trip, began at Megève altiport around 14:30. While the pilot initially encountered clear skies, the flight path toward Valence was interrupted by a significant cloud layer with a ceiling of 4,000 feet.
As the aircraft approached the Vercors massif, the pilot encountered heavy cloud cover that prevented visual navigation to the destination. Noticing a break in the clouds approximately 26 kilometers from the destination, the pilot attempted a low-speed spiral descent. During this maneuver, the aircraft entered a "whiteout" condition, where the lack of contrast between the snow-covered ground and the clouds obscured the terrain. The tail rotor struck trees at an altitude of approximately 20 meters, causing the helicopter to strike the ground heavily. The impact resulted in one passenger seriously injured and the pilot slightly injured, while the aircraft was destroyed.
The investigation
The investigation focused on the meteorological conditions and the pilot's decision-making process. Investigators established that the pilot relied solely on weather information provided by a friend in the Valence area rather than official meteorological reports. During the descent, the pilot experienced a loss of visual references due to the whiteout effect. Furthermore, the investigation found that the aircraft's emergency locator transmitter (ELT) failed to activate. The pilot was unable to use a mobile phone due to lack of signal in the area and had to seek help on foot, eventually encountering hikers who alerted rescuers.