Narrative:
The Ilyushin Il-76MD transport plane operated on a cargo flight to deliver goods from Tashkent, Uzbekistan, to Kabul, Afghanistan. An en route stop was made at Kokand, Uzbekistan. The flight departed at 10:36 hours and climbed to the en route altitude of FL270.
At 11:20 hours the aircraft was cleared to descend FL250 and subsequently to FL230. During the descent the flaps were set at 30° and the spoilers at 20°. The aircraft was then cleared to descend to FL190, after which the controller instructed the flight to maintain that altitude as an Afghanistan Air Force Antonov An-32 was crossing at FL180.
This delayed the descent and the flight leveled off at FL190. Subsequently the flight was cleared down to FL140 and to position for the final approach. At 11:30 the aircraft stalled and rolled left, entering a steep descending spiral. It struck the ground inverted.
The stall of an airplane during maneuvering occurred as a result of a combination of the following factors:
- crew failure to maintain flight speed modes recommended by IL-76 for various airplane configurations, which reduced the available margin of angle of attack to critical modes;
- insufficient control of crew members over the determining flight parameters, which led to a violation of the established restrictions on the permissible angle of attack and the minimum flight speed;
- the lack of piloting skills at high angles of attack, due to the imperfection of the training system for crews in special flight situations;
- the pilots were unable to recognize the exit to critical angles of attack and implement the IL-76 recommendations to prevent stall;
- the need for maneuvering according to the descent scheme in combat conditions at close to flight restriction conditions and the presence of three aircraft flying in clouds at short intervals without appropriate radar control created a difficult situation for the crew, which was aggravated after the controller informed about the need to temporarily stop the descent in connection with the take-off of the An-32 aircraft, which led to a change in the prevailing stereotype of crew actions.
» Andrei Bezmylov
» ICAO Adrep Summary 3/91 (#29)
| Status: | Accident investigation report completed and information captured |
| Date: | Tuesday 27 March 1990 |
| Time: | 11:30 |
| Type: |  Ilyushin Il-76MD |
| Operating for: | Uzbek Civil Aviation Adminstration |
| Leased from: | Soviet Air Force |
| Registration: | CCCP-78781 |
| MSN: | 0083489670 |
| First flight: | 1988 |
| Total airframe hrs: | 1233 |
| Cycles: | 925 |
| Crew: | Fatalities: 9 / Occupants: 9 |
| Passengers: | Fatalities: 0 / Occupants: 0 |
| Total: | Fatalities: 9 / Occupants: 9 |
| Aircraft damage: | Destroyed |
| Aircraft fate: | Written off (damaged beyond repair) |
| Location: | 7,6 km (4.8 mls) E of Kabul Airport (KBL) ( Afghanistan)
|
| Phase: | Approach (APR) |
| Nature: | Cargo |
| Departure airport: | Kokand Airport (UTKK), Uzbekistan |
| Kabul Airport (KBL/OAKB), Afghanistan | |
| Flightnumber: | 3501 |
The Ilyushin Il-76MD transport plane operated on a cargo flight to deliver goods from Tashkent, Uzbekistan, to Kabul, Afghanistan. An en route stop was made at Kokand, Uzbekistan. The flight departed at 10:36 hours and climbed to the en route altitude of FL270.
At 11:20 hours the aircraft was cleared to descend FL250 and subsequently to FL230. During the descent the flaps were set at 30° and the spoilers at 20°. The aircraft was then cleared to descend to FL190, after which the controller instructed the flight to maintain that altitude as an Afghanistan Air Force Antonov An-32 was crossing at FL180.
This delayed the descent and the flight leveled off at FL190. Subsequently the flight was cleared down to FL140 and to position for the final approach. At 11:30 the aircraft stalled and rolled left, entering a steep descending spiral. It struck the ground inverted.
Probable Cause:
The stall of an airplane during maneuvering occurred as a result of a combination of the following factors:
- crew failure to maintain flight speed modes recommended by IL-76 for various airplane configurations, which reduced the available margin of angle of attack to critical modes;
- insufficient control of crew members over the determining flight parameters, which led to a violation of the established restrictions on the permissible angle of attack and the minimum flight speed;
- the lack of piloting skills at high angles of attack, due to the imperfection of the training system for crews in special flight situations;
- the pilots were unable to recognize the exit to critical angles of attack and implement the IL-76 recommendations to prevent stall;
- the need for maneuvering according to the descent scheme in combat conditions at close to flight restriction conditions and the presence of three aircraft flying in clouds at short intervals without appropriate radar control created a difficult situation for the crew, which was aggravated after the controller informed about the need to temporarily stop the descent in connection with the take-off of the An-32 aircraft, which led to a change in the prevailing stereotype of crew actions.
Classification:
Loss of control
Sources:
» Soviet Transports» Andrei Bezmylov
» ICAO Adrep Summary 3/91 (#29)
Photos
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Kokand Airport to Kabul Airport as the crow flies is 677 km (423 miles).
Accident location: Approximate; accuracy within a few kilometers.
Distance from Kokand Airport to Kabul Airport as the crow flies is 677 km (423 miles).
Accident location: Approximate; accuracy within a few kilometers.
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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