108 fatalities

1973-09-30: Tupolev TU-104 (CCCP-42506) — Aeroflot - Russian International Airlines — Sverdlovsk-Koltsovo, Russia

Sverdlovsk-Koltsovo, RussiaTakeoff (climb)

On September 30, 1973, a Tupolev TU-104 (registration CCCP-42506) operated by Aeroflot - Russian International Airlines was involved in an aviation accident near Sverdlovsk-Koltsovo, Russia during takeoff. 108 people were killed. Investigators recorded the probable cause as: The loss of control during initial climb was the consequence of the failure of artificial horizons as a result of a malfunction of the on-board electrical system. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781232216Data APIEditorial standards

An aircraft crashed shortly after takeoff from Sverdlovsk-Koltsovo Airport following loss of control due to instrument failure. None of the 108 occupants survived.

Accident Details

On a night departure from Sverdlovsk-Koltsovo Airport, the aircraft was cleared to climb to 1,500 meters. Air traffic control instructed the crew to initiate a left turn. During the turn, the aircraft first banked left to an angle of 35–40 degrees. At an altitude of 1,200 meters, the left bank angle increased to 75–80 degrees, and control was lost. The aircraft entered a dive and crashed in a wooded area located 10 kilometers from the airport. The impact caused a large explosion and the aircraft disintegrated. None of the 108 occupants survived.

Weather Conditions

At the time of the accident, weather conditions were marginal. Visibility was limited to 6 kilometers, with an overcast ceiling at 800 feet. Wind was from the northwest at 15 knots, and light rain was falling.

Probable Cause

The investigation determined that the loss of control during initial climb resulted from a failure of the artificial horizons due to a malfunction of the on-board electrical system. The combination of night conditions, reduced visibility, and flight instrument failure caused the pilot to experience spatial disorientation, leading to the loss of control.