What happened
During a flight originating from Paris-Orly, the crew received instructions to descend through various flight levels, specifically moving to FL070 and subsequently FL060. Following a directive to execute a right turn toward the Vienne VOR, the aircraft deviated from its intended course after passing the VNE VOR, instead following an incorrect track of 155°.
At approximately 20:58LT, air traffic control transitioned the flight from Lyon-Satolas Approach to Valence Approach. After establishing contact with the new controller, the crew was cleared to descend to 3,500 feet for an arrival route connecting Vienne and Valence. While performing a right turn to 200° at a speed of 187 knots, the aircraft type struck the vertical face of the 'Pierre Chauve' cliff, which stands at an elevation of 1,260 meters near Léoncel. The impact caused the aircraft to disintegrate, and all 22 fatalities were recorded.
Findings
Investigations concluded that the accident was primarily driven by a navigational error. Specifically, the crew utilized the Lyon-Satolas (LSA) VOR instead of the intended Vienne (VNE) VOR. This mistake was compounded by an inadequate mental model of the flight path and a lack of effective cross-checking or division of labor between the crew members.
Several contributing factors were identified that exacerbated the situation:
- The crew's navigation documentation and cockpit organization contributed to potential errors.
- Regional airspace organization near Valence limited the effectiveness of available radar.
- There was an absence of clearly defined task assignments for the crew provided by the operator.
- The co-pilot had a measurable blood alcohol concentration at the time of the event.