What happened
On February 17, 2018, a Beechcraft 95B55, registration N155PR, departed Toussus-le-Noble for Annemasse as part of a family trip. The flight was conducted under Visual Flight Rules (VFR), and the aircraft was not certified for flight in icing conditions. After departing at 15:30, the aircraft's transponder signal disappeared approximately seven minutes later, making radar tracking difficult.
As the flight progressed through the Morvan massif toward the Jura Mountains, the weather conditions deteriorated. While the pilot had previously navigated this route, the weather at the destination was marginal. Around 16:39, the aircraft was positioned near Lons-Le-Saunier. A witness observed the aircraft leaving the Saône valley and entering the Jura massif, where the upper portion of the terrain was obscured by fog. The aircraft subsequently struck the treetops at an altitude of approximately 1,600 ft, causing the aircraft to disintegrate. The pilot and two passengers were killed in the impact.
The investigation
The investigation focused on the aircraft's flight path, the meteorological conditions, and the pilot's decision-making process. Although the transponder signal was lost early in the flight, investigators were able to reconstruct the trajectory using cellular signals from mobile phones found in the wreckage.
Examination of the wreckage revealed that the landing gear was retracted at the time of impact and both engines were producing power. No pre-impact damage was found on the airframe. Investigators also analyzed digital evidence from recovered mobile devices, which showed the pilot had been monitoring weather applications and communicating via SMS regarding the family's arrival and planned ski trip.
Findings
Several factors contributed to the accident:
- The pilot elected to continue the flight despite marginal meteorological conditions that were unsuitable for VFR flight over mountainous terrain.
- There was significant pressure to reach the destination to begin a scheduled family ski holiday.
- An element of overconfidence was present, as the pilot was highly experienced and familiar with the route.
- The decision to proceed through the Jura mountains was inadequate, as the low cloud ceiling and fog obscured the terrain, making a collision with the mountainside highly probable.
- The aircraft was not equipped for IFR (Instrument Flight Rules) operations, leaving no margin for error when the ceiling dropped.