Aeroflot Flight 1912

Aeroflot Flight 1912 was a scheduled domestic Aeroflot passenger flight on the Odessa-Kiev (Kyiv)-Chelyabinsk-Novosibirsk-Irkutsk-Khabarovsk-Vladivostok route that crashed on 25 July 1971, making a hard landing at Irkutsk Airport. It touched down short of the runway, breaking the left wing and catching fire. Of the 126 people on board the aircraft, 29 survived.

Aircraft

The aircraft involved in the accident was a Tupolev Tu-104B, registered CCCP-42405 to the West Siberia Civil Aviation Directorate, a division of Aeroflot. At the time of the accident, the aircraft operated 19,489 flight hours and sustained 9,929 pressurization cycles.

Crew

The crew of the fatal flight took over in Novosibirsk. A total of eight crew members were aboard the flight, of which five were from the cockpit crew.

The cockpit crew consisted of:
* A. V. Ovchinnikov serving as pilot in command
* A. A. Pinchuk serving as co-pilot
* G.P. Guslyakov serving as flight engineer
* I. V. Shchepkin serving as navigator
* V. I. Bolotin serving as radio operator
Flight attendants G. K. Eselevich, L. B. Shokina and A. N. Sorokin served as the cabin crew.

Synopsis

The Odessa-Kyiv-Chelyabinsk-Novosibirsk part of the route was carried out by a different aircraft and crew; the passengers and luggage switching to CCCP-42405 during the stopover in Novosibirsk at Tolmachevo Airport. At 04:34 local time (01:34 Moscow time) this fresh aircraft and crew departed Novosibirsk for Irkutsk. After takeoff the flight maintained an altitude of .

In Irkutsk, the sky was completely covered with stratus clouds with a ceiling of , mild north-easterly winds were present, and visibility was at . The crew was instructed to proceed on the final approach on a bearing of 116°. At 08:10 local time (03:10 Moscow time) the air traffic controller gave flight 1912 permission to begin descent. At 08:29:35 the crew received a landing instructions and permission to descend to an altitude of . The flight crew responded that they heard the information and would begin approach with the ILS. In response, the air traffic controller reported weather conditions to the flight. At 08:31:52 the flight was on approach from the runway. At first, the aircraft stayed on the correct trajectory; but when the aircraft was from the runway, the air traffic controller warned the flight that it was straying to the left. At 08:33:45 local time, when the flight was just from the runway, the air traffic controller warned that they were close to missing the glide slope. In response, the flight crew notified the controller that the landing gear had been released and they were ready to land.

At 08:33:58 received permission to land; the crew confirmed they received the information. At 08:34:18 the crew reported they were near the non-directional beacon. The controller again warned the flight of the slight deviation to the left. The recommended instrument approach speed for the Tu-104 is , but it is very likely that the aircraft's instruments overstated the speed, causing the misinformed crew to try to reduce speed. In reality, the aircraft's speed was around , causing a left bank and a lateral deviation of . At 08:34:47 the aircraft passed the non-directional beacon at an altitude of .

Due to flying less than the recommended speed, the aircraft reached a critical angle of attack. At 08:35:00 with a vertical speed of approximately , the Tu-104 hit the right landing gear on the runway from the base of the runway; milliseconds later the left landing gear, then the front gear, stuck the runway. Shortly thereafter the left wing of the plane broke, fuel leaking from the broken left tanks ignited. The plane skidded on the runway, causing the fuselage to break into pieces. The wreckage of the plane was strewn over an area of . 97 people perished in the crash; the captain, the co-pilot, the flight engineer, a flight attendant, as well as 73 adult passengers and 20 children. 36 of the deaths were from carbon monoxide poisoning.

Causes

The flight was on an approach speed far below the recommended parameters. The instruments most likely gave inaccurate readings, causing the crew to reduce speed before touching the runway led to a hard landing. Examination of the airspeed indicators showed that the indicators themselves were functional, but flight tests showed that changes in cabin pressure affected the pressure in the full-pressure pipeline of the speed indicator used by the co-pilot and the navigator; resulting in an overstatement of the speed ranging from . While simulating the flight to determine the cause of the erroneous indications, the depressurization happened approximately three minutes after turning off the cabin pressurization. The probability of such events occurring during descent was supposed to be 0.000001%.

The investigation cited the three primary causes of the accident as follows:

See also

* Aeroflot Flight 964, also a Tupolev Tu-104, crashed on approach experiencing similar artificial horizon failure.
* Aeroflot Flight 2415, instrument failure of Tu-104 causing crash shortly after takeoff.
* Aeroflot Flight 3932, another Tupolev Tu-104, crashed shortly after takeoff experiencing similar artificial horizon failure.

References

{{Aviation accidents and incidents in the Soviet Union in the 1970s

Aviation accidents and incidents in 1971
20th-century aviation accidents and incidents in Russia
Aviation accidents and incidents in the Soviet Union
1912
1971 in the Soviet Union
1971 in Russia
Accidents and incidents involving the Tupolev Tu-104
Airliner accidents and incidents caused by instrument failure
History of Irkutsk
July 1971 in the Soviet Union