The Saratov Airlines Antonov An-148 took off Sunday from Moscow's Domodedovo airport for a flight to the city of Orsk and went down in a field about 40 miles southeast of the capital.
Russian Ministry for Emergency Situations employees work at the scene of the plane crash.
The An-148 model itself has a very spotty safety record, with one previous crash and a string of major incidents in which pilots struggled to land safely.
The IAC report states that approximately three minutes into the flight, after two warnings from the autopilot that there was an instrument failure, the crew switched off the autopilot. Most victims were from Orsk, where authorities declared Monday to be an official day of mourning. Saratov Airlines commissioned it past year.More news: Call of Duty Movie Aims for Sicario 2 Director
It added that about 400 pieces of the plane have also been found, so far.
The plane was built in Ukraine in 2010 and bought by Saratov Airlines from another Russian airline a year ago, the carrier said. One of the speed indicators was reportedly frozen at zero.
The Ukrainian manufacturer of the plane, Antonov, said Monday it was ready to send its specialists to participate in the investigation.
The Interstate Aviation Committee has yet to confirm the initial findings from the Investigative Committee.
TV footage from the crash site showed airplane fragments lying in the snow. The pilots performed a series of maneuvers and eventually took the plane into a dive at 30 to 35 degrees before it plummeted into a snowy field six minutes after takeoff.