Aeroflot flight 763

Aeroflot flight 763
	An Aeroflot Let L-410
Accident summary
Accident type	Stall at take-off, fall into a river
place	River Aldan , near Ust-Maja , Soviet Union
date	October 14, 1986
Fatalities	14th
Survivors	0
Aircraft
Aircraft type	Let L-410M
operator	Aeroflot
Mark	CCCP-67264
Departure airport	Magan Airport , Soviet Union
Stopover	Ust-Maja Airport , Soviet Union
Destination airport	Allach-Jun Airport , Soviet Union
Passengers	12
crew	2
	Lists of aviation accidents

October 14, 1986 crashed on the Aeroflot flight 763 , a regional transport aircraft of type Let L-410M at the start from the airport Ust-Maya . The plane rolled over the runway and crashed into the Aldan River . All 14 people on board were killed because they could not open the doors of the sinking machine.

machine

The affected machine was a Let L-410M made in Czechoslovakia . The machine had the factory number 780905 and was first delivered in 1978. The Let carried the aircraft registration CCCP-67264 . The twin-engine regional airliner was equipped with two Walter M601A turboprop engines .

Passengers and luggage

There was a crew of two on board, consisting of the master and the first officer. Flight attendants were not provided on this regional flight. There were 11 adult passengers, one child and 88 kilograms of luggage on board.

Flight history

Flight 763 operated a route from Magan to Allach-Jun with a stopover in Ust-Maja . The flight to Ust-Maja went without any special incidents. The crew then worked through the checklist for the onward flight to Allach-Jun. When checking the machine for the onward flight, there were no complaints, the payload was not exceeded and the machine was also loaded with a correct center of gravity.

the accident

During the take-off run, the left engine stalled after reaching the decision speed and only 1.8 seconds before reaching the take-off speed; it then came to a flameout . The pilots brought the propellers of this engine into the sail position and increased the power of the right engine to 96 percent. Shortly afterwards, they let the machine rotate at a speed of 160 km / h . Because of the measures taken to compensate for thrust after the engine failure, the pilots forgot to retract the landing gear after taking off.

At a height of about 10 meters, the aircraft turned to the left. At the end of the runway, the flight path approached obstacles in the form of 10-15 meter high trees at a distance of 80 meters behind the runway end. Within six seconds of take-off, the flight speed initially rose to 164 km / h and was then reduced again to 120 km / h within the next 9 seconds. This was probably due to an attempt by the crew to avoid a collision with obstacles. The pilots succeeded in raising the machine to 40 to 50 meters, but after that the machine could not maintain its altitude with only one engine in operation, the airspeed dropped to 140 km / h.

At the same time, aircraft of the type L-410MU in take-off configuration with an asymmetrical engine power at a flight speed of less than 160 km / h lead to a loss of controllability due to the lack of complete flow around the rudder to compensate for the torque. The aircraft was in an uncoordinated left turn at a high angle of attack above the surface of the Aldan River, while its vertical speed changed from 0.7 to 1.1 meters per second and the airspeed according to the displays decreased from 125 to 90 km / h . The pilots tried to increase the airspeed, but this only increased the rate of descent of the machine.

A stall occurred 119 seconds after take-off at a height of 5 to 10 meters above the Aldan River. The plane crashed into the water 270 meters from the river bank.

Due to the high water pressure, the occupants could not open the doors of the Let L-410. The machine sank into the river within two to three minutes.

Recovery and accident investigation

When rescue teams arrived at the crash site 6 minutes after the crash, they found no trace of the aircraft. The rescue teams also had no boats to save people from the water. There was also no other technical equipment required for rescue and evacuation work. Motorboats, ships of the river fleet and a Mi-8 helicopter carried out the search for the wreck. The wreck was lifted the next day, 31 hours after sinking. The accident victims were examined medically after the rescue. Since the victims had no significant external injuries, the investigators assumed that they were all buckled up at the time of the accident. The cause of death for all victims was drowning.

swell

60.35924 134.451137Coordinates: 60 ° 21 ′ 33 " N , 134 ° 27 ′ 4" E