Background
Aeroflot Flight 37577 was a scheduled domestic passenger flight from Perm to Sovetsky. On November 21, 1989, the aircraft crashed near Sovetsky, resulting in 32 fatalities among the 40 people on board. The flight was operated by a crew of five: commander Valentin Alekseyevich Poteev, copilot Yuri Vasilyevich Perminov, flight engineer Alexander Nikolayevich Shipitsyn, flight engineer-instructor Georgy Evstafyevich Ponosov, and stewardess Galina V. Kamenskikh. The aircraft carried 35 passengers, mostly oil workers.
Aircraft
The accident aircraft was an Antonov An-24B with tail number 46335 (serial number 97305602). It was manufactured on September 30, 1969, and had accumulated 36,861 flight hours and 31,763 takeoff-landing cycles at the time of the accident.
Pre-flight and Departure
The crew completed pre-flight preparation at 10:38 MSK, but the flight was delayed due to worsening weather at Sovetsky. The crew received a weather forecast indicating storm conditions, unstable wind, mist, rain, moderate icing, and low cloud base. At 12:20, the commander received an actual weather report showing conditions above the meteorological minimum, and at 13:15, the crew decided to proceed. The aircraft departed Perm at 13:55 MSK, climbing to flight level 5,700 meters. Only 2,900 kilograms of fuel were loaded, precluding diversion to alternate airports.
Approach and Crash
The aircraft approached Sovetsky at dusk. After receiving updated weather and clearance, the pilots began descent at 17:16. The commander decided that the copilot would fly the aircraft, contrary to An-24 training programs. The crew did not immediately activate the anti-icing system; it was turned on only after the "Icing" warning activated three times. At 17:24, the crew reached the transition level and set altimeters to airport pressure. They continued descending to 500 meters at 17 kilometers from the runway. The controller indicated an ILS approach on heading 304° but did not provide updated weather data or runway markings.
Landing gear was deployed at 17:25:10 at 310–315 km/h, flaps set to 15° at 285 km/h and then 30° at 240 km/h. Decision height was set to 62 meters. At 17:26:40, the crew reported entering the glide slope at 500 meters, 10 kilometers from the runway threshold. However, 6 kilometers from Sovetsky at 250 meters, the vertical speed increased to 5 m/s, unnoticed as the crew corrected a lateral deviation. The aircraft descended below the glide slope, passing the outer marker at 60–90 meters below the required altitude. The pilots then reduced vertical speed to zero and leveled off for about a kilometer before rejoining the glide slope and continuing descent. At 130 meters, the flight engineer failed to call "Assessment" or "Decision height." The crash ensued.
Probable Cause
The source does not state a probable cause.