Russian investigators had decided that the reason two MI-24 Hind combat helicopters crashed in Chechnya on March 20 was that they collided with a mountain during adverse weather conditions. No signs of damage that could have been inflicted on the helicopters from the ground has been found and the flight recorders also indicated some sort of technical failure. 

The MI-24s went missing in mountains in southeastern Chechnya on March 20. They had been escorting two MI-8 Hip transport helicopters and while the MI-8's chief pilot was able to change course in time, he made the command to the rest of the flight too late. The heavier MI-24s are sluggish at that altitude and did not have enough time to climb. 

Search groups found the crash scene of one of Hind in mountains at an altitude of some 3,000m above the sea level on March 25. The second Mi-24, heavily damaged by an onboard fire, was found on April 2 just two kilometers north of the other helicopter. Both crews were killed in the crash. - Adam Geibel