What happened
On the afternoon of January 4, 2003, a pilot operating a Rans Coyote 2 S-6ES ultralight, registration 38-FR, departed from the Grenoble le Versoud airfield. While initially encountering clear skies near Chamrousse, the pilot soon encountered a heavy weather front. As visibility dropped and turbulence increased, the pilot attempted a rapid descent to find a gap in the cloud layer. However, the pilot entered instrument meteorological conditions (IMC) and experienced severe airspeed fluctuations that made compass readings impossible.
At 16:25, the pilot contacted air traffic control to report being lost. After spotting a rock face in close proximity, the pilot deployed the aircraft's emergency parachute. The descent was brief, and the aircraft landed on a snowy slope near the Grand Doménon lake. Due to high winds, the inflated parachute dragged the aircraft toward a rocky outcrop. The pilot was forced to cut the parachute lines with a knife to prevent further movement and used the parachute fabric for warmth to survive the night.
Following an overnight stay in freezing conditions, the pilot trekked through deep snow to the La Pra refuge. After successfully contacting a helicopter via the emergency frequency the following afternoon, the pilot was evacuated at 16:00 in a state of severe exhaustion and hypothermia.
The investigation
The investigation focused on the meteorological conditions and the pilot's decision-making during the flight. Investigators examined the weather reports from the Grenoble le Versoud ATIS, which indicated an approaching active cold front with potential thunderstorms. The investigation also reviewed the pilot's actions regarding communication with air traffic control and the subsequent survival efforts in the mountains.