Incident Overview
On a flight from Paris-Orly, the crew received clearances to descend to FL070 at 2049 local time and then to FL060 at 2055. An instruction to turn right to 178° toward the VOR of Vienne was given, but after passing VNE VOR, the aircraft followed a wrong track of 155°. At 2058, the crew was transferred from Lyon-Satolas Approach to Valence Approach, with radio contact established 30 seconds later. The crew was cleared to descend to 3,500 feet for a specified arrival route Vienne–Valence. A right turn to 200° was initiated when, at a speed of 187 knots, the aircraft struck the vertical cliff of 'Pierre Chauve' (1,260 meters high) near Léoncel. The aircraft disintegrated on impact, and all 22 occupants were killed.
Investigation Findings
The official investigation determined that the accident was the direct result of a navigational error. This error had two direct causes: the display and use of the VOR LSA (Lyon-Satolas) instead of VNE (Vienne), and an insufficiency in the mental representation of the aircraft's path despite other available information. Contributing factors included a lack of rigor in the division of work, in its execution, and in mutual control. The investigation also noted that several circumstances facilitated the development of a critical situation: the documentation used by the crew for navigation and the organization of the dashboard could be sources of error; the organization of airspace in the Valence region did not allow optimal use of existing radar; the tasks of the crew were not defined by the operator; and the copilot had a moderate but significant blood alcohol level.