Aeroflot Flight 6551

1973 Aeroflot Il-18 crash

49°35′30″N 80°23′0″E / 49.59167°N 80.38333°E / 49.59167; 80.38333AircraftAircraft typeIlyushin Il-18BOperatorAeroflotRegistrationСССР-75687Flight originBina Airport, Baku, Azerbaijan SSRStopoverTashkent Airport, Tashkent, Uzbek SSRDestinationSeverny Airport, Novosibirsk, Russian SFSROccupants63Passengers55Crew8Fatalities63Survivors0

Aeroflot Flight 6551 (Russian: Рейс 6551 Аэрофлота Reys 6551 Aeroflota) was a scheduled domestic passenger flight on an Ilyushin Il-18B from Baku to Novosibirsk with a stopover in Tashkent that crashed on 11 May 1973 over Semipalatinsk in the Kazakh SSR, killing all 63 people aboard.^[1]

Aircraft

The aircraft involved in the accident was an Ilyushin Il-18B registered CCCP-75687 to the Azerbaijan division of Aeroflot. Built in 1959, by the time of the accident the aircraft had sustained 21,663 flight hours and 11,787 pressurization cycles. Initially the cabin layout was designed to seat 80 passengers but later seats were rearranged to seat an additional nine passengers.^[2]

Crew

Eight crew members were aboard the flight. The cockpit crew consisted of:^[3]

Captain – Viktor Sergeyevich Loginov
Co-pilot – Yuri Aleksandrovich Filin
Flight engineer – Valentin Nikolayevich Pershin
Navigator – Viktor Mikhaylovich Filatov
Radio operator – Dmitry Korneyevich Markin^[3]

Synopsis

The flight departed from Tashkent Airport on the May 10 at 23:25 Moscow time (01:25 May 11 local time) with 63 people on board, including three children. The aircraft leveled at a cruising altitude of 7,800 metres (25,600 ft) after takeoff until they were instructed by the Almaty Airport region controller at 00:56 MSK to increase altitude to a flight level of 9,000 metres (30,000 ft) and fly on a bearing of 43 degrees; the flight crew confirmed receiving the instruction and proceeded to ascend as directed. At 01:12 MSK the flight briefly contacted the Ayaguz airport controller and again at 01:22 to inform him they were about to depart the Ayaguz sector and head over to Semipalatinsk. After contacting the Semipalatinsk controller the flight proceeded to decrease altitude to 7,800 metres (25,600 ft) by initiating a 360-degree left turn; the aircraft was last seen on radar 110 kilometres (68 mi; 59 nmi) from Semipalatinsk but had been in flight 90 kilometres (56 mi; 49 nmi) from the airport, not detected by radar. The Semipalatinsk controller attempted to make contact with the plane when it was due to be overhead at 01:52 MSK (04:52 local time) but received no response from the flight. At the time the weather consisted of clouds at altitudes of 1,000–1,300 metres (3,300–4,300 ft), mild wind and rain, with visibility at 10 kilometres (6.2 mi; 5.4 nmi).^[4]

At the time the Il-18 was flying on autopilot when within the span of six seconds the instrument speed decreased from 400 to 370 km/h (220 to 200 kn; 250 to 230 mph) while at its assigned altitude before entering a rapid decline with no lateral roll, reaching overloads ranging from 1.5 to -0.8g. 17 seconds later the plane entered a right bank with an angular velocity of more than 100 degrees per second, causing overloads that resulted in the loss of the right wing at an altitude of 5,000 metres (16,000 ft) while at a speed of 670 km/h (360 kn; 420 mph) and the breakup of the fuselage at an altitude of 3,600 metres (11,800 ft) at a speed of 700 km/h (380 kn; 430 mph), well above the maximum safe speed of an Il-18 (675 km/h (364 kn; 419 mph)). At 04:37 local time (01:37 Moscow time), 38 seconds after the start of the decline, the remains of the aircraft crashed into the steppe, 84 kilometres (52 mi; 45 nmi) south of Semipalatinsk. Investigators were able to reach the wreckage and view the burning debris by 04:50 local time, but all 63 people on the flight perished in the crash.^[4]

Conclusions

Two local military units questioned by investigators reported that they had not fired any projectiles into the air around the time of the crash nor were there any air force aircraft in operation that could have collided with the flight. Investigators felt that the first altitude and speed of the 20–30 seconds of reduced altitude correlated with a controlled emergency reduction in altitude, followed by an unexplainable loss of control that led to an overspeed situation. Investigators thought that one of the reasons possible would have been a crew member unintentionally losing control of an elevator during an emergency descent, but it could not be conclusively confirmed. At the time of the rapid decline that led up to the accident, the propellers were feathered, but it is unknown if the crew had done so or if the autopilot had done so.^[4]

Two round puncture holes in the fuselage of the rear luggage compartment; investigators had the portion of the compartment recovered and sent for analysis to see if an artillery shell could have caused the damage, but analysis concluded that the holes resulted from the crash itself with a lack of explosive residues present. Despite the recovery of the flight data recorders and most of the wreckage, the commission was not able to pinpoint an exact cause of the crash, in part due to the amount of damage sustained by the flight data recorders limiting the amount of information that could be recovered.^[4]

References

^ "ASN Aircraft accident Ilyushin 18B CCCP-75687 Semipalatinsk". aviation-safety.net. Retrieved 2017-12-29.
^ "Ильюшин Ил-18Б Бортовой №: СССР-75687". russianplanes.net. Retrieved 2017-12-29.
^ ^a ^b "Авиакатастрофа Ил-18Б близ Семипалатинска. 1973". avia.pro. Retrieved 2017-12-29.
^ ^a ^b ^c ^d "Катастрофа Ил-18Б Азербайджанского УГА близ Семипалатинска". www.airdisaster.ru. Retrieved 2017-12-29.

Aeroflot

Part of the SkyTeam alliance

Subsidiaries

Active	Pobeda Rossiya
Inactive	Dobrolet Donavia Orenair SAT Airlines Vladivostok Air
Exited	Aurora Nordavia (now Smartavia)

Fleet

Accidents and
incidents

1950s	Flight 31 (1955) 1957 Kiev mid-air collision Flight 04 Тu-104 Kanash crash Flight 120 Flight 200 Flight 315
1960s	Flight 315 Flight 207 Flight 036 Flight 068 Flight 245 Flight 902 Flight 415 Flight 03 Flight 213 Flight 191 Flight 25 Flight 012 Flight 366 Flight 663 Flight 721 Flight 101/X-20 Flight 542 Flight 513 Flight 99 Flight 065 Flight 2723 Flight 5003 Flight 2230 Flight L-51 Flight 1668 Flight 15 Flight 831 Flight N-826
1970s	Flight U-45 Flight 1661 Flight 3630 CCCP-11000 crash CCCP-12996 crash Flight 1969 Flight 1912 Flight 773 Flight 2174 Flight 1491 Flight 558 Flight 1036 Flight 217 Flight 6263 Flight 141 Flight 630 Flight 6551 Flight 109 Flight A-13 Flight 3932 Flight 964 Flight 19 Flight 2022 CCCP-75559 crash Flight 662 Flight 2003 Flight 3739 Flight 909 Flight 1802 Flight 418 Flights 7957 and 31 (1976) Flight 2415 Flight N-36 Flight 3843 Flight 5003 Flight 331 Flight B-2 Flight 6709 Flight 1080 Flight 1691 Flights 7628 and 7880 Flight 5484
1980s	Flight 4225 Flight 498 Flight 811 Flight 3603 Flight 8641 Flight 411 Flight 343 Flight 5463 Flight 601 Flight 3352 Flight 3519 Flight 7841 1985 Zolochiv mid-air collision Flight 5143 Flight 101/435 Flight 2306 Flight 6502 Flight 892 Flight U-505 Flight N-528 Flight 699 Flight 3739
since 1990s	CCCP-46472 crash Flight 2808 Flight 593 Flight 521 Flight 821 Flight 1492

v t e Aviation accidents and incidents in 1973 (1973)
Jan 21 Aeroflot Flight 6263 Jan 22 Kano Nigeria Airways Boeing 707 crash Jan 29 EgyptAir Flight 741 Feb 19 Aeroflot Flight 141 Feb 21 Libyan Arab Airlines Flight 114 Feb 24 Aeroflot Flight 630 Feb 26 DeKalb–Peachtree Airport Learjet 24 crash Mar 3 Balkan Bulgarian Airlines Flight 307 Mar 5 Nantes mid-air collision Apr 10 Invicta International Airlines Flight 435 May 11 Aeroflot Flight 6551 May 18 Aeroflot Flight 109 May 31 Indian Airlines Flight 440 Jun 3 Paris Air Show Tu-144 crash Jun 10 Nepal plane hijacking Jun 20 Aeroméxico Flight 229 Jul 11 Varig Flight 820 Jul 22 Pan Am Flight 816 Jul 23 Japan Air Lines Flight 404 Jul 23 Ozark Air Lines Flight 809 Jul 31 Delta Air Lines Flight 723 Aug 13 Aviaco Flight 118 Aug 18 Aeroflot Flight A-13 Aug 28 TWA Flight 742 Sep 8 World Airways Flight 802 Sep 11 JAT Flight 769 Sep 27 Texas International Airlines Flight 655 Sep 30 Aeroflot Flight 3932 Oct 13 Aeroflot Flight 964 Nov 2 Aeroflot Flight 19 Nov 3 Pan Am Flight 160 Nov 3 National Airlines Flight 27 Nov 21 US Navy C-117D Sólheimasandur Crash Nov 23 Italian Air Force C-47 Argo 16 crash Nov 25 KLM Flight 861 Dec 16 Aeroflot Flight 2022 Dec 17 Iberia Flight 933 Dec 17 Pan Am Fl. 110, Lufthansa Fl. 303 hijacking Dec 22 Royal Air Maroc Caravelle crash
1972 ◄ ► 1974

Aviation accidents and incidents in 1973 (1973)

Jan 21

Aeroflot Flight 6263

Jan 22

Kano Nigeria Airways Boeing 707 crash

Jan 29

EgyptAir Flight 741

Feb 19

Aeroflot Flight 141

Feb 21

Libyan Arab Airlines Flight 114

Feb 24

Aeroflot Flight 630

Feb 26

DeKalb–Peachtree Airport Learjet 24 crash

Mar 3

Balkan Bulgarian Airlines Flight 307

Mar 5

Nantes mid-air collision

Apr 10

Invicta International Airlines Flight 435

May 11

Aeroflot Flight 6551

May 18

Aeroflot Flight 109

May 31

Indian Airlines Flight 440

Jun 3

Paris Air Show Tu-144 crash

Jun 10

Nepal plane hijacking

Jun 20

Aeroméxico Flight 229

Jul 11

Varig Flight 820

Jul 22

Pan Am Flight 816

Jul 23

Japan Air Lines Flight 404

Jul 23

Ozark Air Lines Flight 809

Jul 31

Delta Air Lines Flight 723

Aug 13

Aviaco Flight 118

Aug 18

Aeroflot Flight A-13

Aug 28

TWA Flight 742

Sep 8

World Airways Flight 802

Sep 11

JAT Flight 769

Sep 27

Texas International Airlines Flight 655

Sep 30

Oct 13

Nov 2

Nov 3

Nov 3

National Airlines Flight 27

Nov 21

US Navy C-117D Sólheimasandur Crash

Nov 23

Italian Air Force C-47 Argo 16 crash

Nov 25

KLM Flight 861

Dec 16

Aeroflot Flight 2022

Dec 17

Iberia Flight 933

Dec 17

Pan Am Fl. 110, Lufthansa Fl. 303 hijacking

Dec 22

Royal Air Maroc Caravelle crash

1972 ◄ ► 1974

Aviation accidents and incidents in the Soviet Union

1930s	Osoaviakhim-1 SSSR-V6 Osoaviakhim
1940s	1948 Aeroflot Ilyushin Il-12 crash
1950s	1950 Sverdlovsk plane crash LOT Polish Airlines Flight 232 1957 Kiev mid-air collision Aeroflot Flight 04 1958 Aeroflot Tu-104 Kanash crash Aeroflot Flight 315 (1959) Aeroflot Flight 120 Aeroflot Flight 200
1960s	Aeroflot Flight 315 (1960) U-2 incident Aeroflot Flight 207 RB-47 shootdown incident Aeroflot Flight 036 Austrian Airlines Flight 901 Aeroflot Flight 068 Aeroflot Flight 245 Aeroflot Flight 902 Aeroflot Flight 415 Aeroflot Flight 213 (1962) Aeroflot Flight 191 Aeroflot Flight 03 Aeroflot Flight 25 Aeroflot Flight 012 Aeroflot Flight 366 Aeroflot Flight 663 Aeroflot Flight 721 Aeroflot Flight 101/X-20 Aeroflot Flight 542 Aeroflot Flight 513 Aeroflot Flight 99 Aeroflot Flight 065 Aeroflot Flight 2723 Aeroflot Flight 5003 (1967) Aeroflot Flight 2230 Aeroflot Flight L-51 Aeroflot Flight 15 Seaboard World Airlines Flight 253A 1969 Yukhnov mid-air collision Aeroflot Flight N-826
1970s	Aeroflot Flight U-45 Aeroflot Flight 1661 Dymshits–Kuznetsov hijacking affair Aeroflot Flight 3630 Aeroflot Flight 244 22 January 1971 Surgut Aeroflot Antonov An-12 crash 31 January 1971 Surgut Aeroflot Antonov An-12 crash Aeroflot Flight 1969 Aeroflot Flight 1912 Malév Flight 110 Aeroflot Flight 773 Aeroflot Flight N-63 Aeroflot Flight 2174 Aeroflot Flight 1491 Aeroflot Flight 558 Aeroflot Flight 1036 Aeroflot Flight 217 Japan Air Lines Flight 446 Aeroflot Flight 6263 Aeroflot Flight 141 Aeroflot Flight 630 Balkan Bulgarian Airlines Flight 307 Aeroflot Flight 6551 Aeroflot Flight 109 Aeroflot Flight A-13 Aeroflot Flight 3932 Aeroflot Flight 964 Aeroflot Flight 19 Aeroflot Flight 2022 1974 Leningrad Aeroflot Il-18 crash 1974 Surgut mid-air collision Aeroflot Flight 2003 Aeroflot Flight 3739 (1976) Aeroflot Flight 909 Aeroflot Flight 1802 Aeroflot Flight A-53 Aeroflot Flight 418 1976 Anapa mid-air collision Aeroflot Flight 2415 Aeroflot Flight N-36 Aeroflot Flight 3843 Aeroflot Flight 5003 (1977) 1977 Aeroflot Tupolev Tu-134 hijacking Aeroflot Flight B-2 Aeroflot Flight 6709 Korean Air Lines Flight 902 1978 Yegoryevsk Tu-144 crash Iranian Chinook shootdown Aeroflot Flight 1080 Aeroflot Flight 1691 1979 Dniprodzerzhynsk mid-air collision Aeroflot Flight 5484
1980s– Dec. 1991	Aeroflot Flight 4225 1981 Pushkin Tu-104 crash Aeroflot Flight 498 1981 Armenia mid-air collision 1981 Zheleznogorsk mid-air collision Aeroflot Flight 811 Aeroflot Flight 3603 Aeroflot Flight 8641 Aeroflot Flight 411 Aeroflot Flight 5463 Korean Air Lines Flight 007 Aeroflot Flight 601 Aeroflot Flight 3352 Aeroflot Flight 3519 Aeroflot Flight 7841 1985 Zolochiv mid-air collision Aeroflot Flight 5143 Aeroflot Flight 101/435 Aeroflot Flight 2306 Aeroflot Flight 6502 Aeroflot Flight U-505 Aeroflot Flight N-528 Aeroflot Flight 699 Aeroflot Flight 3739 (1988) 1988 Soviet Air Force Il-76 crash An-24 crash in Navoiy Aeroflot Flight 8556

v t e Aviation accidents and incidents in Kazakhstan
Aeroflot Flight 101/X-20 (1965) Aeroflot Flight 6551 (1973) Aeroflot Flight 3843 (1977) Aeroflot Flight 4225 (1980) Aeroflot Flight 5463 (1983) Kazakhstan Antonov An-72 (2012) SCAT Airlines Flight 760 (2013) Bek Air Flight 2100 (2019)
This includes accidents in the Kazakh SSR and post-independence Kazakhstan.