Narrative:
The Antonov 2 was prepared for a flight from Sangar to Sebyan and Kyuel in Siberia. Because of poor weather the flight was delayed a couple of hours. The flight crew members repeatedly visited the meteorological office. At the time of the planned departure weather at Sangar was reported as: visibility more than 10 km, scattered clouds at 800 m, overcast at 3000 m, temperature -22° C, dewpoint -23° C, pressure 765 mm Hg. Weather forecast en route included a few stratocumulus clouds between 1400 and 1700 m, significant altostratus clouds between 2700 and 3500 m. The mountainous area over which the Antonov was to fly moderate orographical turbulence was present in the layer from 900 to 1700 meter, and possible downdrafts on the lee side of ridge in the same altitude range. These conditions were not reported to the crew.
Then medical equipment with a weight of 400 kg and passengers arrived at the airport by ambulances. The captain expected seven passengers, but three additional passengers had arrived, without having tickets. The names were added to the passenger list and the copilot arranged the payment of the fare. No seats were available for two passengers, so they had to sit on some hand luggage in the aisle. At 04:46 UTC the aircraft departed from Sangar and climbed towards the mountainous terrain. The highest point along the route was at an elevation of 1976 m. The minimum safe altitude was 2515 m. The pilot climbed VFR and maintained visual separation from the snow-covered mountains. At an altitude of 1300 m the Antonov entered an area with strong turbulence. The aircraft was caught in a downdraft. In an attempt to stop the plane from descending further, power was added to nominal, then to the takeoff power. With rising terrain it was impossible to continue. The pilot decided to carry out a 180-degree turn to the left over downsloping terrain. This brought the plane downwind with a 30-degree bank instead of the recommended 20 degrees. As a result, the vertical rate of descent increased. Having rolled through 120 degrees, the left lower wing contacted a cliff. The aircraft lost speed and crash-landed on the mountain slope.
CAUSAL FACTORS:
- the crew carried out a flight at a height lower than the minimum safe altitude;
- incorrect estimation by the crew of the prevailing situation, which led to a late decision to return to the airport of departure under the conditions of orographical turbulence and airspace limited by mountains;
- deficiencies in the flight instructions at the airport Of Sangar, due to the absence a.o. of an altitude diagram of the route of flight, which would have shown that it was impossible for the airplane, according to its technical flight characteristics, to gain enough height within 10 km after takeoff ;
- the incorrect weather forecast along the flight course, in which the orographical turbulence was not provided ;
- the erroneous actions of the crew in the process of the downwind turn with a bank angle of 30° while carrying out the delayed decision to return to the airport of departure, leading to an increase in the vertical rate of descent.
(translated from Russian)
Loss of control
» Russian Ministry of Transport document No.8.15-754
| Status: | Accident investigation report completed and information captured |
| Date: | Friday 18 November 2005 |
| Time: | 14:07 |
| Type: |  Antonov An-2TP |
| Operator: | Polyarnye Avialinii |
| Registration: | RA-02252 |
| MSN: | 1G234-06 |
| First flight: | 1989 |
| Engines: | 1 PZL Kalisz (Shvetsov) ASz-62IR |
| Crew: | Fatalities: 0 / Occupants: 2 |
| Passengers: | Fatalities: 0 / Occupants: 10 |
| Total: | Fatalities: 0 / Occupants: 12 |
| Aircraft damage: | Damaged beyond repair |
| Location: | 31 km (19.4 mls) from Sangar ( Russia)
|
| Phase: | En route (ENR) |
| Nature: | Ambulance |
| Departure airport: | Sangar, Russia |
| Sebyan, Russia |
The Antonov 2 was prepared for a flight from Sangar to Sebyan and Kyuel in Siberia. Because of poor weather the flight was delayed a couple of hours. The flight crew members repeatedly visited the meteorological office. At the time of the planned departure weather at Sangar was reported as: visibility more than 10 km, scattered clouds at 800 m, overcast at 3000 m, temperature -22° C, dewpoint -23° C, pressure 765 mm Hg. Weather forecast en route included a few stratocumulus clouds between 1400 and 1700 m, significant altostratus clouds between 2700 and 3500 m. The mountainous area over which the Antonov was to fly moderate orographical turbulence was present in the layer from 900 to 1700 meter, and possible downdrafts on the lee side of ridge in the same altitude range. These conditions were not reported to the crew.
Then medical equipment with a weight of 400 kg and passengers arrived at the airport by ambulances. The captain expected seven passengers, but three additional passengers had arrived, without having tickets. The names were added to the passenger list and the copilot arranged the payment of the fare. No seats were available for two passengers, so they had to sit on some hand luggage in the aisle. At 04:46 UTC the aircraft departed from Sangar and climbed towards the mountainous terrain. The highest point along the route was at an elevation of 1976 m. The minimum safe altitude was 2515 m. The pilot climbed VFR and maintained visual separation from the snow-covered mountains. At an altitude of 1300 m the Antonov entered an area with strong turbulence. The aircraft was caught in a downdraft. In an attempt to stop the plane from descending further, power was added to nominal, then to the takeoff power. With rising terrain it was impossible to continue. The pilot decided to carry out a 180-degree turn to the left over downsloping terrain. This brought the plane downwind with a 30-degree bank instead of the recommended 20 degrees. As a result, the vertical rate of descent increased. Having rolled through 120 degrees, the left lower wing contacted a cliff. The aircraft lost speed and crash-landed on the mountain slope.
Probable Cause:
CAUSAL FACTORS:
- the crew carried out a flight at a height lower than the minimum safe altitude;
- incorrect estimation by the crew of the prevailing situation, which led to a late decision to return to the airport of departure under the conditions of orographical turbulence and airspace limited by mountains;
- deficiencies in the flight instructions at the airport Of Sangar, due to the absence a.o. of an altitude diagram of the route of flight, which would have shown that it was impossible for the airplane, according to its technical flight characteristics, to gain enough height within 10 km after takeoff ;
- the incorrect weather forecast along the flight course, in which the orographical turbulence was not provided ;
- the erroneous actions of the crew in the process of the downwind turn with a bank angle of 30° while carrying out the delayed decision to return to the airport of departure, leading to an increase in the vertical rate of descent.
(translated from Russian)
Classification:
TurbulenceLoss of control
Sources:
» Michael Roch» Russian Ministry of Transport document No.8.15-754
Photos
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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