[4] CCCP-12996 was sent to transport goods from Tyumen to Surgut, the aircraft's load consisted of 12 metric tons of fresh seafood; Pacific herring packed in boxes.

[4] At Surgut the sky was fully covered by layered cloud down to an altitude of 240 m (787.4 ft), a fresh breeze was blowing from the South-South-West, visibility was 6 km (3.7 mi), the air temperature was −7 °C (19.4 °F).

At 02:30 Moscow time and 120 km (74.6 mi) from their destination, the crew made radio contact with the radar controller at Surgut airport and received a weather report.

[4] The commission that investigated the accident concluded that: The stall during the final approach immediately after completion of the third turn was the result of icing on the wing tips.

Both crashes occurred under similar circumstances, whilst carrying out the third turn of their landing circuit both aircraft suffered spontaneous rolls due to flow separation on the wing caused by a drop in aerodynamics because of icing, which in turn was caused by ineffective de-icing systems since the hot air intake valve from the engine was not fully open.

In order to prevent further catastrophes of the same nature significant improvements were made to the air bleed control systems including an indicator to show the fully open position of the valves.