A Russian passenger plane that crashed in Siberia killing 31 people had not been treated with de-icer before take-off, officials reported.
The ATR-72, a twin-engine turboprop, came down shortly after leaving Roshchino international airport in Tyumen, about 1,000 miles east of Moscow, with 39 passengers and four crew on board.
Twelve people survived with serious burns and other injuries after being pulled from the wreckage.
The crash took place four minutes after take-off and the crew did not relay any information to air traffic controllers before impact.
Investigators told Russian media that the most likely cause was an accretion of ice or frost on the plane’s fuselage, which can disrupt air flow over the wings and jam ailerons. Vladimir Nesmachny, the deputy head of Roshchino airport, was quoted as saying the crew had decided not to treat the plane with a de-icing agent before flying.
“Usually that decision is taken by the pilot, it’s his right,” he said. “In this case, it wasn’t done.”
An ATR-72 plane crashed in the United States in 1994 after it flew through freezing rain, and an investigation found the aircraft was vulnerable to “icing”.
The Tyumen crash is the latest in a series of deadly air disasters in Russia. In September, 44 people including the entire Lokomotiv Yaroslavl ice hockey team died after a Yak-42 crashed into a riverbank near the city of Yaroslavl. That followed another catastrophe in June when a Tu-134 flying from Moscow crashed in Karelia region, killing 47 people on board.
The ATR-72, belonging to passenger airline UTair, crashed about 20 miles from Tyumen, after taking off for Surgut, also in Tyumen region.
The short-haul plane caught fire and broke apart on impact. All four crew were reported to have died. Survivors were airlifted to hospital by helicopter. Pictures from the scene showed wreckage strewn across a snowy field. The passengers were mostly residents of Tyumen and Surgut, two major west Siberian oil towns.
The ATR aircraft manufacturer is a joint venture between EADS, a pan-European corporation, and the Italian company, Alenia Aermacchi.