7 fatalities

1971-01-31: Antonov AN-12 (CCCP-12996) — Aeroflot - Russian International Airlines — Surgut, Russia

Surgut, RussiaLanding (descent or approach)

On January 31, 1971, an Antonov AN-12 (registration CCCP-12996) operated by Aeroflot - Russian International Airlines was involved in an aviation accident near Surgut, Russia during landing or approach. 7 people were killed. Investigators recorded the probable cause as: The aircraft lost control due to significant ice accumulation on the wing tips. 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 1781235510Data APIEditorial standards

An Ilyushin Il-76 cargo flight operating between Tyumen and Surgut crashed into an icy lake during its final approach, resulting in the deaths of all seven people on board.

What happened

A cargo flight traveling from Tyumen to Surgut was conducting a night approach when the aircraft experienced sudden instability. The flight was transporting 12 tons of herring and included six crew members and one passenger. While flying at an altitude of approximately 400 meters and a speed of 330 km/h, the captain requested a configuration change to flaps 15. Following this command, the aircraft began oscillating with left and right rolls.

Shortly after the instability began, the plane entered a nose-down descent. The airspeed increased to 395 km/h before the aircraft impacted an icy lake at a 90-degree left bank. The impact occurred roughly 13.6 km from the runway threshold. The crash resulted in seven fatalities and the total destruction of the Ilyushin Il-76.

Findings

Investigations concluded that the primary reason for the accident was a loss of control resulting from excessive ice buildup on the wing tips. Several contributing elements were identified during the inquiry, including the presence of severe icing conditions during the flight. Additionally, the crew's management of de-icing systems was noted as a factor, specifically regarding the use of engine air bleeding.

Probable cause

The aircraft lost control due to significant ice accumulation on the wing tips.