A dozen passengers had a miraculous escape when a M1-8 helicopter fell on its side while landing.
The helicopter carrying 17 people lurched on its side on takeoff, with 5 described as being in a 'grave' condition.
A criminal case into possible negligence was opened after the Mi-8 crashed in a mountainous area of Khabarovsk region.
A helicopter carrying ammonite - used to break ice - crashed in Irkutsk region after 'exploding in mid air'.
Early morning crash involved Hyundai passenger bus and Mercedes Benz minibus.
Mystery over circumstances of crash when chopper was on 'unsactioned' flight.
The Mi-8 with 25 passengers and a crew of three on board crash landed some 45 km into a flight, said early reports.
Aircraft had been flying as part of a test flight following an engine change when it came down.
A desperate rescue mission saved four people - but up to 24 are feared dead in the air tragedy in the Sakha Republic.