Accident
A special flight departed Vélizy-Villacoublay Air Base bound for Orange Air Base. The aircraft was carrying six officers, seven engineers from the Commissariat à l’Énergie Atomique (CEA), and a crew of eight, tasked with inspecting the nuclear center of Pierrelatte. Marseille air traffic control cleared the pilot to descend to 8,000 feet until Montélimar, then to 5,000 feet to Orange. For unknown reasons, the crew began the descent prematurely. In marginal weather conditions, the aircraft struck the slope of Mt Suc de Pradou, elevation 1,342 meters, located about 3 kilometers southeast of Mézilhac. The wreckage was found approximately 200 meters below the summit. All 21 occupants were killed.
Occupants
The crew consisted of Lieutenant Pierre Chaintreau, Adjutant/C Jean-Michel Reig, Adjutant/C Jacques Deville, Adjutant Alain Gaudy, Sergeant/C Claude Touzeau, Sergeant/C Jean-Pierre Boutin, Officer Alain Giblan, and Soldier Bertrand Courbier. Passengers included Admiral Robert Landrin, General Édouard Billion, General Jean-Marc Pineau, Colonel Charles Birckel, Colonel Alain Rolland de Chambaudoin d’Erceville, Captain André Bouteiller, and engineers Jean Gaume, Paul Johann, Jean Labussière, Hubert Lefèbvre de Laboulaye, Jacques Mabile, François Ronteix, and Georges Tirole.
Investigation
The official investigation concluded that the crew likely misunderstood and mixed the two altitude clearances: 8,000 feet until Montélimar and 5,000 feet to Orange, leading to a premature descent. The accident was determined to be a controlled flight into terrain.