Aeroflot Flight 101/X-20 ( Reys 101/X-20 Aeroflota) was a scheduled domestic passenger flight from Moscow to Alma-Ata via Omsk, Soviet Union, that crashed in low visibility conditions on 4 January 1965, killing 64 of the 103 people on board.
Aircraft
The aircraft involved in the accident was an Ilyushin Il-18B registered CCCP-75685 to the Kazakh Civil Aviation Directorate of Aeroflot. The aircraft had sustained 6802 flight hours.
Crew
Eight crew members were aboard the flight. The cockpit crew consisted of: Captain Konstantin Sergeevich Artamonov Check captain and Head of the Kazakh Civil Aviation Directorate Rishat Nurmukhametovich Azakov Co-pilot Nikolai Aleksandrovich Slamikhin Flight engineer Anatoliy Galiyevich Shakirov Navigator Vladimir Vasiliyevich Pristavka Radio operator Nikolay Nikolayevich Safonov
Synopsis
The flight was scheduled to depart from Domodedovo airport at 07:30 on January 4, but was delayed by necessary engine repairs. The flight did not depart from Domodedovo until 10:20 and arrived at Omsk airport at 15:52 Moscow time. The flight was supposed to depart from Omsk thereafter for a short flight to Alma-Ata. At the same time, head of the Kazakh aviation division R. Azakov had just returned from investigating a Mil Mi-4 crash and inspected the undercarriage of the Il-18 before it was cleared for the next leg of the journey. The flight's destination was delayed for 2 hours 28 minutes because visibility at Alma-Ata airport was less than , which meant that the airport had to close for safety reasons. At 19:30 Moscow time the flight departed from Omsk en route to Alma-Ata and maintained a cruising altitude of .
At 20:15 Moscow time the weather at Alma-Ata was reported to have a visibility of , wind was weak, and atmospheric pressure was 710.5 mmHg. At 20:32, a different Il-18, registered CCCP-75689, landed on runway 23 bearing after twice failing to land on the reciprocal (RWY 05) and having to execute a go-around. While taxiing to the apron, the operations manager asked the Il-18 if it would be safe for another Il-18 to land in the same weather. The pilot responded by categorically denying that any Il-18 could safely land in the current conditions. The controller then told Flight 20 to proceed to its alternate, Sary-Arka Airport; but five minutes later the operations manager reversed the previous instruction and told Flight 20 to begin a descent to and then to for landing at Alma-Ata. In violation of procedure, the controller did not inform the flight of the visibility or cloud-base prevailing at the airport.
At an altitude of 3000 meters the flight contacted air traffic control and received permission to descend to an altitude of . The landing was to be carried out on runway 23. The controller did warn of the presence of fog at the airport, but said that it had subsided a bit and he did not expect visibility to go below the minimum safe level. The crew began to execute the approach as planned, but after turning onto final approach the aircraft was to the right of the centerline of the runway. When the aircraft was away from the runway threshold, the controller instructed the crew to decrease altitude to and warned that visibility was starting to worsen. When the aircraft was from the end of the runway it established itself on the glidepath and continued its descent for the landing.
The visibility at the airfield had reached , well below the published minimum; the controller did not inform the flight or the operations manager of the situation. As a result, the aircraft continued its approach instead of diverting to its alternate, as conditions required it to do. The non-directional beacon lights pulsed, but the aircraft began to deviate to the left slightly. The controller notified the crew of the deviation and instructed them to correct course by 2° and follow the lights to approach the runway. The crew acknowledged the controller's transmission and stated that they saw the beacon lights. The controller then instructed the flight to change course by 3°, with the result that the aircraft went from being slightly to the left of the extended centreline to slightly to the right. The controller advised the crew to execute a missed approach, but the crew ignored the instruction and continued with the landing.