Aeroflot Flight 37577

Aeroflot

Industry	Airline
Founded	1923 (1923)
Headquarters	Moscow , Soviet Union
Products	Passenger air transport

Template:Infobox aircraft occurrence

Aeroflot Flight 37577 was a domestic passenger service operating between Perm and Sovetsky. On November 21, 1989, the Antonov An-24B involved crashed near Sovetsky, resulting in the deaths of 32 out of the 40 individuals aboard.

Aircraft

The aircraft involved was an An-24B bearing tail number 46335 and manufacturer serial number 97305602. It was produced by the Antonov Serial Production Plant on September 30, 1969. By the time of the incident, it had logged a total of 36,861 flight hours and completed 31,763 takeoff and landing cycles.

Preceding events

Operating as charter flight 37577 from Perm to Sovetsky, the plane transported oil industry personnel. The flight crew included commander Valentin Alekseyevich Poteev, copilot Yuri Vasilyevich Perminov, flight engineer Alexander Nikolayevich Shipitsyn, flight engineer-instructor Georgy Evstafyevich Ponosov, and stewardess Galina V. Kamenskikh. At 10:38 Moscow Time (MSK), pre-flight preparations were finalized; however, deteriorating weather conditions at Sovetsky caused a delay. The crew received a weather forecast covering 12:00 to 19:00 indicating storm activity, unstable fresh winds, mist, persistent stratiform rain clouds with broken rain cloud layers, moderate icing conditions, cloud base at 80 meters and top at 500 meters, with visibility limited to approximately one kilometer. At 12:20, updated actual weather information for Sovetsky reported light northeasterly winds, continuous cloud cover at roughly 180 meters altitude, snow mixed with mist, and visibility extending to three kilometers—conditions exceeding meteorological minimum requirements. Consequently, at 13:15 the decision was made to proceed with the flight. Departure from Bolshoye Savino Airport occurred at 13:55 MSK with climb authorized to flight level 5,700 meters. There were 35 passengers aboard. Prior to takeoff, fuel loading amounted to only 2,900 kilograms—insufficient for diversion to alternate airports such as Perm or Nizhnevartovsk if required.

Crash

The aircraft neared Sovetsky during dusk. After receiving the current weather update for 16:50 (14:50 MSK) and clearance from air traffic control, the pilots initiated their descent at 17:16. Contrary to the An-24 crew training protocols, the commander assigned control of the aircraft to the copilot during this stage. The crew also delayed activating the anti-icing system, which was eventually switched on just before passing the outer marker, but only after the "Icing" alert had sounded three times. At 17:24, they reached the transition level of 1,200 meters, adjusted their altimeters to the airport level pressure, and reported this to the controller. After verifying their altimeters, they continued descending until 500 meters altitude, approximately 17 kilometers from the runway. The controller instructed that the approach would be conducted using the ILS on a heading of 304°, but failed to provide updated weather information or details about runway location and markings, breaching established procedures.

At 17:25:10, with an indicated airspeed between 310 and 315 km/h, the landing gear was lowered. The flaps were initially set to 15° at a speed of 285 km/h and later adjusted to 30° (landing configuration) at 240 km/h. The radio altimeter's decision height was programmed to 62 meters. At 17:26:40, the commander reported intercepting the glide slope at 500 meters altitude, roughly 10 kilometers from the runway threshold, and commenced descent following the approach pattern.

Approximately 6 km (3.7 mi) from Sovetsky at an altitude of 250 m (820 ft), the vertical speed unexpectedly increased to 5 m/s; however, this went unnoticed by the crew as they were focused on correcting lateral deviation. Consequently, the aircraft descended below the glide slope, passing the outer marker between 60 and 90 meters beneath the required altitude (120–150 meters instead of the mandated 210). Upon realizing this discrepancy, the pilots gradually reduced vertical speed to zero and maintained level flight for about one kilometer until rejoining the glide slope before resuming descent. At 130 meters altitude, the flight engineer failed to call "Assessment," nor did he announce "Decision height" upon reaching 100 meters. Additionally, the commander did not communicate his assessment at decision height. The flight engineer-instructor present in the cockpit did not intervene to rectify these procedural oversights made by the evaluated crew.

When only 300 meters from the runway threshold, updated weather conditions were transmitted by air traffic control; these conditions fell below minimum requirements for an An-24 approach, indicating a need for a go-around. Despite this, the crew continued without initiating a go-around. At an altitude of 75 meters, vertical speed increased again to 6 m/s, creating a critical situation. After descending past the radio altimeter's decision height of 62 meters—at which point its warning sounded—the descent persisted. Only upon reaching approximately 35 meters did pilots realize they were heading toward a forested area and abruptly pulled back on their control yokes, raising the nose and causing an increase in load factor to nearly one-and-a-half times normal limits. Simultaneously, an engine power advance to takeoff thrust was applied without command. Despite these actions, they failed to fully arrest their descent in time.

At roughly 180 meters from the outer marker, the right wing collided with trees. This impact destroyed that wing section and shut down the right engine; its propeller automatically entered feather mode. Meanwhile, the left engine had already begun accelerating to takeoff power just seconds after throttle advancement, generating asymmetric thrust. Combined with uneven lift caused by damage to the right wing, this led to a rightward roll reaching a bank angle of 27°. The crew attempted corrective measures using full rudder and aileron inputs, initially reducing bank angle to about 12°. However, shortly thereafter, due to stall on the compromised right wing, roll angle rapidly increased again at a rate of approximately 16° per second. At 17:28:47, with nearly a 90° right bank angle, the An-24 crashed into a highway embankment before crossing it and striking an earthen berm where it broke apart and caught fire. Emergency responders found eight passengers with severe injuries at the site; all other passengers—27 in total—and all five crew members lost their lives.

Causes

Template:Center The An-24 aircraft accident resulted from a combination of several factors:

• inadequate crew readiness for landing under the prevailing conditions and poor teamwork, including improper allocation of responsibilities between the captain and first officer, which caused deviation from the prescribed approach path and an early descent below the decision height amid challenging weather without visual cues from the terrain.
• the crew's breach of the established minimum landing altitude for this aircraft type during an ILS approach, involving a rapid descent aimed at acquiring visual contact with ground references at dangerously low levels.
• persistent failure by both captain and first officer to execute a go-around upon reaching decision height, despite receiving alerts from air traffic control about worsening vertical visibility and the radio altimeter’s warning at 62 meters, which hindered correction of approach errors.
• neglect by the supervising flight engineer-instructor in adequately overseeing and evaluating the crew’s performance.