Aeroflot flight F-637
| Aeroflot flight F-637 | |
|---|---|
.jpg) A similar Let L-410 from Aeroflot |
|
| Accident summary | |
| Accident type | Loss of control after instrument failure |
| place | near Gridino, Kostroma Oblast , Soviet Union
|
| date | 4th December 1984 |
| Fatalities | 10 |
| Survivors | 0 |
| Aircraft | |
| Aircraft type |
 Let L-410M
|
| operator |
Aeroflot
|
| Mark |
CCCP-67225
|
| Departure airport |
Kostroma Airport , Soviet Union
|
| Stopover |
Ivanovo Airport , Soviet Union
|
| Destination airport |
Ulyanovsk Airport , Soviet Union
|
| Passengers | 8th |
| crew | 2 |
| Lists of aviation accidents | |
December 4, 1984 accident on the Aeroflot flight F-637 , a regional transport aircraft of type Let L-410mA on a flight from Kostroma to Ivanovo . All 10 people on board were killed in the accident.
machine
The affected machine was a Let L-410M made in Czechoslovakia . The machine had the factory number 770706 and was first delivered to Aeroflot on June 17, 1977. The Let carried the aircraft registration CCCP-67264 . The L-410 prevailed against the Soviet Beriev Be-32 in a tender by the Council for Mutual Economic Aid (Comecon) and was therefore used by airlines from almost all Comecon member countries. The twin-engine regional airliner was equipped with two Walter M601 turboprop engines . By the time of the accident, the machine had completed 3534 operating hours, which accounted for 3007 take-offs and landings.
Passengers and crew
There was a two-man crew on board, consisting of the flight captain Viktor Igorewitsch Würtz and the first officer Nikolai Petrovich Sweginez. Flight attendants were not provided on this regional flight. There were 8 passengers on board.
Weather
On the day of the accident, the sky was covered with stratus clouds , the cloud cover was at a height of 220 meters, wind of 280 ° 5 m / s in drizzle and haze. The visibility was 4 kilometers.
Flight plan
The flight plan for Aeroflot flight F-637 provided for a take-off from Kostroma and the flight to end in Ulyanovsk . A stopover in Ivanovo was planned.
Course of the flight and course of the accident
The Let took off at 08:08 for the first flight segment to Ivanovo. While the machine was climbing to 1500 meters, the artificial horizon failed . Since the aircraft was flying through a cloud cover at this point, the pilots became spatially disoriented due to the lack of optical reference points. The machine went into a descent, during which the roll angle increased continuously. At an altitude of 500–600 meters the Let flew out of the cloud cover. Since the natural horizon was now available to them as an optical reference point for orientation, the pilots were able to regain control of the Let. While they were busy intercepting the aircraft from its descent, they flew again into a cloud cover. They suffered another spatial disorientation and lost control of the machine. The Let brushed against some trees and at 8:13 a.m. fell to the ground in a forest near the village of Gridino, southeast of Kostroma. All 10 inmates were killed.
Accident investigation
The investigation into the accident was made more difficult by the fact that the aircraft had neither a flight data recorder nor a cockpit voice recorder . After the impact, there was no fire, the debris field extended over an area of 15 by 195 meters.
During the investigation into the accident, it was found that the machine had flown into the cloud cover 1 minute and 10 seconds after take-off at a height of 200 meters. The pilots then switched to instrument flight. The climb initially went according to plan. At an altitude of 530 meters, the pilots had contacted air traffic control again and reported a change in course from 137 degrees to 150 degrees to Privolsk . At about the same time it came to the emergency. After the pilots had flown the right turn, the machine assumed an increasingly larger roll angle to the left, which was 55 degrees after 20 seconds. Over the next two minutes, the roll angle was reduced to 20 to 25 degrees. Shortly thereafter, the roll angle increased to 73 degrees, with the rate of descent to 50 meters per second, with an indicated airspeed of 485 km / h, which was above the top speed of the machine of 410 km / h. As the vertical rate of descent increased and the roll angle increased, the crew tried in vain to prevent the machine from sinking further by vigorously deflecting the elevator. When it emerged from the cloud cover, the pilots had vigorously intercepted the machine from its descent, but they had not been able to continue to fly the machine below the cloud cover.
It could be determined that the function of the artificial horizons was inadvertently deactivated during technical work on the machine on the ground. The forensic medical examination of the pilots 'bodies also revealed stress-related organ failure ( shock kidney ), which, according to the investigators, could have had a negative impact on the pilots' flying skills.
swell
- Aircraft accident report on airdisaster.ru
- Accident report on russianplanes.net
- Accident report in the Aviation Safety Network
- Operating history of the machine on rzjets.net
Individual evidence
- ↑ Jochen K. Beek: Airplanes of the world 1919-2000 , Motorbuchverlag, ISBN 3-613-02008-4
Coordinates: 57 ° 43 ′ 1 ″ N , 41 ° 7 ′ 56.2 ″ E