Prior to takeoff from Chelyabinsk the crew forgot to activate the pitot heating system. The departure and en route part of the flight were uneventful until the flight was descending for Domodedovo. At an altitude of 3600 m the Tu-154 passed a zone of heavy rainfall and icing. This caused blocking of the pitot tube and incorrect airspeed indications. The airspeed indicator soon went down to zero. The crew mistakenly thought the aircraft was about to stall. They immediately entered a steep descent with the engines at takeoff power. Then aircraft was levelled again at a height of 800 meters. The descent had been flown at a maximum of 100 m/s at a high speed of 813 km/h. The airplane pulled 3.2 G in the process. The high loads on the airframe caused substantial structural damage. The airplane landed safely at Domodedovo. Conclusion By the reason for emergency were improper actions of crew for the piloting during the distorted indications of the indicators of the indicated speed in icing conditions because of not the start it heating PPD, which led to the recovery to the uncalculated flight conditions.