Preflight and Departure
During the preflight briefing, the crew was informed about poor weather conditions in Sofia, with visibility below landing minima. The airplane departed Burgas Airport at 1901 local time. En route, the captain decided to divert to Plovdiv, where weather conditions were considered better.
Descent and Collision
The first radio contact with approach control in Plovdiv was established at 1950 local time, and the crew received clearance to descend. Twelve minutes later, while descending at night with limited visibility, the airplane struck the slope of a mountain located in the Rhodopes Mountain Range near the city of Smolyan. The wreckage was found a few hours later approximately 56 km southwest of Plovdiv Airport. All 35 occupants on board were killed.
Investigation Findings
Investigators determined that the first radio contact was with a civilian controller at 1950 local time. Four minutes later, that controller was relieved by a military controller, who cleared the aircraft to descend without knowing its exact position. The airplane subsequently descended below the minimum descent altitude. The lack of visibility was considered a contributing factor.