At 14:34 Moscow time the Il-18 departed Vnukovo International Airport and climbed to its cruising altitude of 8,000 m (26,000 ft).

While in level flight cruising at 630 km/h the flight engineer inadvertently moved the flaps selector to full extension of 40 degrees and due to the large amount of drag and the Il-18's peculiar aerodynamic design the aircraft pitched over and entered a steep descent.

As the airliner gained speed in its dive the port and starboard flap assemblies were ripped from the wing by high aerodynamic forces.

At 16:00 the aircraft impacted the ground at very high speed with the landing gear retracted and at a pitch angle of 107 degrees.

Unlike the Ilyushin Il-14 aircraft, the Il-18 did not have a mechanism to prevent accidental flap selector movement and this was found to be a contributing factor in the accident sequence.