Russian investigators have disclosed that the Utair Boeing 737-500 involved in a landing accident at Usinsk struck a snow bank with its main undercarriage just before touching down.
The aircraft hit the bank, sustaining damage, about 15m before reaching runway 13 as it arrived following a service from Moscow Vnukovo on 9 February, according to federal air transport regulator Rosaviatsia.
After the aircraft came to a halt on the runway, resting on its engines and fuselage underside with its heading 80° off the centreline, passengers evacuated through slides and the overwing exits.
Inspectors found the right-hand main landing-gear assembly had been torn off the 737 and was located about 1,000m from the aircraft.
Its left main gear had collapsed and folded under the wing. The collapse also damaged inboard flaps and other wing structures.
The wind had been from 150° at 12kt but gusting to 21kt at the time of the arrival, about 12:25.
None of the 94 passengers and six crew members suffered serious injuries.
Meteorological data from the regulator states that the cloud base was at 450m (1,480ft) with visibility of 1,700m. Wintry conditions prevailed with temperatures of minus 21C.
Utair had initially claimed that windshear had contributed to the accident.
Rosaviatsia has not given the height of the 737 at the point of impact with the snow bank, or any information regarding snow clearance at the airport.