Aeroflot Flight 976

Cause

On 21 December 1955 the crash site was discovered from the air on the 2,078-metre-high Tordoki Yani, the highest mountain in the Sikhote-Alin range. It lay at 1,750 m, 20 m below the summit, on its southeastern flank. The following year, between 12 and 14 January 1956, investigators examined the burnt-out wreck. On the basis of the clocks found, the time of the crash could be determined as 12:07.

On the night of the accident, strong winds of up to 85–90 km/h blew from the northwest onto the mountain range lying perpendicular to them. Downdraughts occurred at Tordoki Yani, resulting in a loss of height of up to 400 m. Studies indicating a loss of height of up to 1,000 m were not pursued further. According to regulations, aircraft in such weather conditions in mountains had to fly at least 1,000 m above the highest mountain. Owing to the altimeter setting, 2,700 m was indicated, but taking the atmospheric conditions into account the Li-2 was actually flying at 2,490 m.

The weather conditions were neither taken into account in the flight planning, nor were the pilots briefed. Neither in Yuzhno-Sakhalinsk nor in Khabarovsk did air traffic control check the weather conditions along the route, and it did not assign a safe flight altitude. In addition, there is no radar or radio monitoring in the 40–50 minutes of flight beyond Sovetskaya Gavan, although this is the most dangerous part of the route, which moreover unnecessarily led over Tordoki Yani. Had the route been moved 35–40 km to the north, flight safety would have been massively increased through greater clearance from the ground.

When the Li-2 finally got into the downdraught, the pilots tried to arrest the descent with maximum thrust, but struck the mountain at a shallow angle.