Mountain Collision During Ferry Flight from Minsk to Bamako (TZ-ABH)

Flight Details and Impact Location The aircraft was operating a ferry flight from Minsk, Belarus, to Bamako, Mali, with intermediate stops in Zagreb, Marseille, Oran, and Tamanrasset. It was returning to its country after maintenance at the Minsk factory. During a night cruise in poor weather, the crew did not recognize that the aircraft had deviated from the prescribed flight path. At 10,000 feet, the aircraft struck the slope of Mt L'Avalanche, located about 1,500 meters west of Estenc in the Alpes-Maritimes. The wreckage was found hours later, and the aircraft was totally destroyed on impact. All seven occupants were killed: five crew members and two passengers, who were mechanics. ## Navigation, Weather, and Communication Factors At the time of the accident, the aircraft's equipment was compliant, but stormy weather and strong winds made precise navigation impossible because the aircraft lacked a VOR receiver. On the Genoa–Albenga–Nice route, the aircraft failed to follow the G7 airway due to stormy weather and in accordance with ATC. The Russian pilot-in-command spoke neither English nor French and could not converse directly with ground control. The co-pilot spoke French but not Russian and could not converse directly with the captain or translate the captain's orders from the ground. The navigator, responsible for the route in difficult conditions, could communicate with the pilot only by radio. Only the radio could translate ground-control instructions given in French into Russian for the captain, a process that could introduce interpretation errors and required time. The ICAO recommendation that the pilot-in-command use English or the language used by the ground station was not applied. The investigation found that the crew was unaware of wind and drift. A wind from sector 210 at 100 km/h caused a drift of about 20 degrees toward the north, toward the mountain. Vertical to Nice, the aircraft was already 25 kilometers north of the station and north of the G7 airway. The diversion order did not have to be understood the first time because the crew requested repetition. The simultaneous orders to turn and descend probably made interpretation tricky and ambiguous. The order to make a 360-degree right turn, meaning a circular turn, was erroneously understood as an order to take heading 360. At least five kilometers before impact, the aircraft was following a straight path on a heading oriented almost to magnetic north. Stormy areas northwest of Nice produced unstable radiocompass indications that prevented position control, and turbulence added difficulty. The aircraft approached the terrain as fast as it had been moving north, and its speed on that heading increased by about 100 km/h, representing the wind speed from the south-southeast. The point of impact was at 2,440 meters, while level 80, toward which the aircraft was normally descending, corresponded to an altitude of 2,380 meters.