The pilots of the Russian airliner, which crashed on 11 February, have been blamed for the accident. According to the investigators, the pilots failed to switch on a heating unit, which led the speed sensors to ice up and provide wrong information.
"A factor in the development of a special situation in the flight could be the wrong data about flight speed on pilots' indicators which was likely due to iced pitot tubes (speed probes) while their heating systems were shut off," The New York Post quoted the Russian Interstate Aviation Committee as saying.
"A special situation began to develop about two minutes and 30 seconds after the takeoff at an altitude of around 1,300 meters and the indicator speed of 465-470 km/h," the committee added.
The flight recorders captured varying data from the plane's two airspeed sensors, which is a result of the pilots' failure to turn on the heating unit for the pressure measurement equipment prior to takeoff.
Before the plane slammed into the ground, one of the sensors continued to show a speed of 0 kmh while the other showed a speed of 800 kmh.
The Russian Interstate Aviation Committee, however, still needs to analyse the voice recorder that captured conversations in the cockpit.
A criminal case on charges of violations of flight safety and aircraft operation rules entailing the death of two or more people through negligence has been opened.
On February 11, Russian plane Antonov An-148 operated by Saratov Airlines crashed several minutes after taking off, killing all 71 people aboard.
Fragments of the aircraft were recovered near the Stepanovskoye settlement in the Ramensky District, Moscow region.
The aircraft was heading towards Orsk from Moscow's Domodedovo airport.