What happened
On November 28, 2001, a pilot operating a Yakovlev Yak 50, registration RA 01096, departed from Dijon Longvic for a flight to Sion, Switzerland. The pilot intended to fly under Visual Flight Rules (VFR), planning to navigate between two distinct cloud layers.
After passing over the Arbois airfield, the aircraft climbed to 6,500 feet, where it encountered severe icing conditions. As the aircraft approached the Jura mountains, the two cloud layers merged, obscuring the pilot's visibility. The pilot attempted to turn back using GPS guidance, but upon reaching the Arbois area again, the airfield was no longer visible due to the deteriorating weather.
Finding a temporary break in the cloud cover and spotting the ground, the pilot decided to perform a precautionary landing in a field near Chamole. During the landing roll, the aircraft encountered uneven terrain, causing the left wingtip to strike the ground, resulting in slight damage to the left wing spar.
The investigation
The investigation focused on the pilot's decision-making regarding weather conditions and the sequence of events leading to the forced landing. Investigators examined the meteorological reports (METAR and TAF) for the Dijon and Sion areas, as well as the aircraft's flight path and the pilot's experience. The investigation established that the pilot had encountered significant icing and a loss of visual references during the flight.