The aircraft took off from runway 14R at Moscow's Domodedovo Airport at 14:21 hours local time (11:21 UTC). Weather about the time of departure at Domodedovo Airport included limited visibility (2100m) during light snowfall. Temperature was -5°C, overcast cloud deck at 2600 feet AGL.
The Interstate Aviation Committee stated that, prior to departure, the heating of the three pitot tubes had not been turned on.
After takeoff, at an altitude of 130-150 m (425-490 ft) above ground level, the autopilot was switched on. Flaps were raised as the aircraft climbed through an altitude of 550 m (1800 feet).
About 2 minutes 30 seconds after the takeoff, at an altitude of about 1300 meters (4265 feet) and an instrument speed of 465-470 km/h, there were discrepancies between the air speed readings on the captain's side compared to the standby airspeed indicator. The airspeed on the copilot's side is unknown as this parameter was not registered by the flight data recorder. There were no significant difference in the altitude indications. After another 25 seconds, the discrepancies reached about 30 km/h with the speed on the captain's side being greater.
After about 50 seconds, at an altitude of about 2000 meters (6560 ft), the airspeed on the standby airspeed indicator was higher and continued to increase while the airspeed on the captains ASI continued to decrease.
The flight crew then disconnected the autopilot. The airspeed on the captain's side continued to decrease, while the standby ASI showed 540-560 km/h. About 50 seconds after the autopilot was turned off, the flight passed an altitude of 1700-1900 m (5580-6230 ft) with vertical loads ranging from 1.5 to 0.5 g. Subsequently the aircraft entered a steep descent with the ASI on the captain's side showing 0 km/h, and the standby ASI showing 200 km/h. The pitch angle decreased to -30/-35 degrees with a vertical load factor of 0 g.
The aircraft impacted a snowy field around 14:27:05 and disintegrated. Before the collision with the ground, the standby ASI had increased to 800 km/h with the captain's ASI still displaying 0 km/h.