Aeroflot Flight 663

In the Khoni area, the crew unexpectedly encountered a severe thunderstorm, with the lower cloud limit being 300–400 meters, and the visibility not exceeding 3 kilometers.

Despite bad weather, Heteshvili decided not to return to the airport or follow the roundabout through Poti, but instead try to bypass the thunderstorm on the right side of the mountains.

Bypassing to the right, the plane was flying at an altitude of 900 meters when it hit a zone with heavy rain, which the radio operator reported to the ground at 10:52.

[2] According to the weather forecast, a thunderstorm was expected on the main flight route, with stratocumulus and cumulonimbus clouds having a lower limit of 600–1000 meters and a horizontal visibility of 4–10 kilometers.

The pilot knew that there was a thunderstorm on the main route from Kutaisi to Sukhumi, while on the roundabout (via Poti) weather conditions were good.

This was probably caused by the fatigue of the pilot, who, at the request of the deputy chief of the airport, was delayed from the night shift and had been working for around 14 hours.