Crash of an Antonov AN-24RV in Bugulma: 41 killed

Date & Time: Nov 26, 1991 at 0502 LT
Type of aircraft:
Operator:
Registration:
CCCP-47823
Survivors:
No
Schedule:
Nizhnevartovsk - Bugulma
MSN:
17307204
YOM:
1971
Country:
Region:
Crew on board:
4
Crew fatalities:
Pax on board:
37
Pax fatalities:
Other fatalities:
Total fatalities:
41
Circumstances:
The aircraft departed Nizhnevartovsk on a charter flight to Bugulma, carrying four crew members and 37 employees from an oil company. Weather conditions in Bugulma were poor with clouds down to 80 metres, icing conditions and a visibility of 800 metres. At an altitude of 1,100 metres on approach, the crew encountered icing conditions but did not consider it necessary to activate the deicing systems. Still descending to the altitude of 900 metres, the icing alarm sounded in the cockpit but the captain decided to continue the approach in such configuration. After the crew selected the flaps down to an angle of 30°, he was cleared to land when the aircraft became unstable and departed the approach path to the right. After the aircraft crossed the permissible deviation limit, the crew was instructed by ATC to initiate a go-around procedure. The captain increased engine power and initiated a go-around maneuver when the aircraft adopted a high angle of attack then stalled and pitched down to an angle of 75-80°. At a speed of 260 km/h, the aircraft struck the ground 802 metres short of runway and was destroyed upon impact. The wreckage was found 598 metres to the right of the extended runway centerline and all 41 occupants were killed.
Probable cause:
The accident was the consequence of the combination of the following factors:
- Icing conditions and poor weather conditions that were underestimated and misevaluated by the flight crew,
- An excessive accumulation of frost on the stabilizers (up to 15 millimetres),
- Failure of the crew to activate the deicing systems prior to enter the clouds,
- The decision of the captain to continue the approach after the icing alarm sounded,
- The crew selected flaps down to an angle of 30° without inspecting the wings and stabs surfaces, (in icing conditions, flaps should be deployed in 15° max),
- The flaps were not retracted when the crew initiated the go-around procedure, which caused the aircraft to adopt a high angle of attack,
- Poor crew interactions,
- Lack of crew supervision and mutual monitoring and checks.

Crash of an Antonov AN-24B in Bugulma: 38 killed

Date & Time: Mar 2, 1986 at 0304 LT
Type of aircraft:
Operator:
Registration:
CCCP-46423
Survivors:
No
Schedule:
Moscow - Cheboksary - Bugulma
MSN:
0 73 041 08
YOM:
1970
Flight number:
SU77F
Country:
Region:
Crew on board:
4
Crew fatalities:
Pax on board:
34
Pax fatalities:
Other fatalities:
Total fatalities:
38
Aircraft flight hours:
31570
Aircraft flight cycles:
23765
Circumstances:
On approach to Bugulma Airport by night, the left propeller autofeathered. The aircraft speed dropped and the aircraft started to veer to the left. The crew elected to maintain directional control but the speed continued to drop. At a speed of 140 km/h, the aircraft banked left to an angle of 110° then stalled and crashed in a field located 8 km from the runway threshold and 500 meters from its extended centerline. The aircraft was totally destroyed and all 38 occupants were killed.
Probable cause:
The left propeller autofeathered one second after the flaps were deployed in an angle of 38° because an electrical switch connected to the automatic feathering system failed. This situation affected the aircraft stability and controllability and the crew was unable to correct abnormal yaw and roll following several errors.

Crash of a PZL-Mielec AN-2 in Bugulma: 2 killed

Date & Time: Nov 11, 1979 at 0951 LT
Type of aircraft:
Operator:
Registration:
CCCP-70219
Flight Phase:
Survivors:
Yes
Schedule:
Bugulma – Menzelinsk – Aktanysh – Izhevsk
MSN:
1G138-37
YOM:
1972
Flight number:
SU1535
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
15
Pax fatalities:
Other fatalities:
Total fatalities:
2
Aircraft flight hours:
3561
Circumstances:
The departure from Bugulma was scheduled at 0805LT but postponed first to 0900LT due to poor weather conditions en route. Shortly before takeoff at 0950LT, three additional passengers enplaned, giving a total of 15 passengers (the maximum allowed was 12). One minute after liftoff, during initial climb, at a height of 15 meters, the airplane's speed decreased to 60 km/h then it veered to the left, stalled and crashed. A passenger was killed while another one was uninjured. 15 others occupants were injured and a second passenger died from his injuries five days later, on November 16. At the time of the accident, weather conditions were considered as normal and the total weight of the aircraft and its CofG were within limits.
Probable cause:
It was determined that the loss of control during initial climb occurred after the pilot got distracted. For any reason, he adopted a wrong takeoff configuration and failed to take appropriate actions to maintain a positive rate of climb and a sufficient speed.

Crash of a Yakovlev Yak-40 in Kazan

Date & Time: Apr 9, 1974
Type of aircraft:
Operator:
Registration:
CCCP-87369
Flight Phase:
Survivors:
Yes
Schedule:
Kazan - Bugulma
MSN:
9 34 19 31
YOM:
1973
Country:
Region:
Crew on board:
3
Crew fatalities:
Pax on board:
31
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
During the takeoff roll, after a distance of 650 meters, the engine n°2 failed. The captain decided to continue the takeoff procedure but power and speed were insufficient to rotate. In such conditions, he abandoned the takeoff maneuver but unable to stop within the remaining distance, the aircraft overran and eventually collided with a earth mound. The cockpit was destroyed. All 34 occupants were evacuated, some of them were injured.
Probable cause:
Wrong decisions on part of the captain who continued the takeoff procedure with one engine almost inoperative. Investigations revealed that engine n°2 lost 90% of its power during the takeoff roll for unknown reasons.