August 1969 Il-18 crash

Aeroflot Flight 1770

Il-18V of Aeroflot
Accident
Date	26 August 1969 (1969-08-26)
Summary	Crew errors, wheels-up landing
Site	Vnukovo Airport 55°35′39″N37°16′20″E / 55.59417°N 37.27222°E / 55.59417; 37.27222
Aircraft
Aircraft type	Ilyushin Il-18V
Operator	Aeroflot (Moscow TU GA, Vnukovsky OAO)
Registration	CCCP-75708
Flight origin	Adler Airport, Sochi, RSFSR
Stopover	Vnukovo Airport, Moscow, RSFSR
Destination	Alykel Airport, Norilsk, RSFSR
Occupants	101
Passengers	94
Crew	7
Fatalities	16
Survivors	85

On Tuesday, August 26 1969, an Aeroflot Il-18 crashed at Vnukovo Airport. Of the 101 people on board, 16 were killed.

Aircraft

The Il-18V (in some reports, Il-18B) with tail number 75708 (factory number 189001705, serial number 017-05) was manufactured by MMZ "Banner of Labor" on December 26, 1959, and by January 23, 1960, it had entered service with the 235th Separate Aviation Detachment. In July 1961, this aircraft was used to transport the first cosmonaut, Yuri Gagarin, to Egypt. On October 12, 1961, the aircraft was transferred to the Polar Aviation Administration, and on January 11, 1968, it was assigned to the Vnukovo Aviation Detachment of the Moscow Civil Aviation Administration. By the time of the crash, the aircraft had logged 12,023 flight hours and 4,367 landings. ^{[1] [2]}

Flight 1770

The aircraft was operating flight 1770 on the route Sochi—Moscow—Norilsk, piloted by a crew from the 65th Flight Detachment, consisting of Captain Anatoly Khomchenko, Co-pilot Viktor Brakhnov, Navigator Valery Voronkov, Flight Engineer Ivan Mukhin, and Radio Operator Olga Petrova. Flight attendants Inna Gorelova and Natalia Terekhova were working in the cabin. After takeoff from Sochi Airport and reaching cruising altitude, the aircraft maintained an altitude of 7,800 meters. There were 94 passengers on board. ^[2]

As the aircraft approached Moscow in the evening, the captain instructed the radio operator to read the checklist for descent and landing. The radio operator read the checklist up to the "Landing Gear" item, as the other items had to be performed after the landing gear was extended during the approach. At 20:18, the aircraft began descending from 7,800 meters to 5,100 meters towards Serpukhov; weather and air traffic conditions were normal. According to the standard approach procedure, the landing at Vnukovo Airport should have followed a rectangular pattern. However, the captain was determined to take a shortcut to descend to the correct altitude by the third turn, avoiding the rectangular pattern. As a result, the Il-18 descended at a vertical speed of 28 m/s, nearly three times the allowable 10 m/s, violating the limitations specified in the flight operations manual (FOM). ^[2]

During further descent, the aircraft leveled off at 1,200 meters and reached the calculated point when the controller instructed a 30° turn to ensure the necessary landing interval but did not specify the position of the other aircraft. The crew, in a state of agitation due to the rush for landing, began searching for the other aircraft and forgot to perform one of the critical steps in the landing preparation—lowering the landing gear. This was exacerbated by the deactivated warning siren for the retracted landing gear, which was allowed by the Civil Aviation Administration's regulations because its operation could prevent crew members from hearing each other. However, deactivating the siren also disabled the landing gear position indicator lights, which shared the same circuit breakers with the audible system (although the gear position could still be monitored by the indicators on the instrument panel). The warning system was never reactivated. ^[2]

After completing the fourth turn and aligning with the final approach, the captain forgot to instruct the flight engineer to read the remaining checklist items. The flight engineer, in turn, also forgot and did not check the landing readiness, thus failing to notice that the landing gear was still retracted. After passing the outer marker, the crew did not report landing readiness, but the tower controller, not waiting for the required report, still cleared the aircraft to land on the runway. ^[2]

Accident

At 20:31, the Il-18 landed on its belly (due to the retracted landing gear) at Vnukovo Airport. Upon impact with the runway, the propeller blades began breaking and flying in all directions, including into the fuselage. Blade fragments punctured the fuselage skin and damaged the hydraulic system pipelines as well as electrical wiring. The leaked AMG-10 hydraulic fluid ignited, causing a fire that began spreading through the cabin. The aircraft skidded 1,180 meters down the runway before coming to a stop. The pilots, still unaware of what had happened, activated the engine fire suppression systems, forgetting about the passengers in the cabin. The navigator rushed to the cabin and found it filled with smoke. Together with the flight attendants and passengers, the navigator opened the front and rear entrance doors and two of the four emergency exits. ^[2]

Unaware that the landing had been on the belly and believing that the landing gear was extended, the navigator and flight attendants tried to hold back the passengers, fearing they might be injured by falling from a height. However, the panicking crowd pushed the flight attendants outside. In the evening darkness, the evacuation was chaotic and took more than three minutes. Contrary to the "women and children first" rule, women with children were among the last to leave, according to the navigator. No one counted the evacuated passengers, so it was unclear how many people remained inside. The crew members in the cockpit escaped through the windows. Airport emergency services arrived at the crash site only 15–20 minutes later and soon extinguished the fire. Both passenger cabins were heavily burned, but none of the survivors suffered burns, and even their clothing showed no signs of fire exposure. Nonetheless, 16 passengers died in the incident: two men, ten women, and four children. All died from smoke inhalation, with 15 perishing at the rear of the second cabin and one at the front of the first. ^[2]

Causes

The main cause of the crash was the improper performance of their duties by the captain and the flight engineer during the preparation and execution of the landing, as defined in the FOM and the crew's standard operating procedures during approach. This led to the landing being carried out with the landing gear retracted. The immediate cause of the fatalities was smoke inhalation resulting from a fire that started when AMG-10 hydraulic fluid ignited due to an electrical short circuit in the aircraft's wiring. ^[2]

The following factors also contributed to the crash: ^[2]

• Low discipline and inadequate training in the 65th Flight Detachment;
• Lack of proper oversight during the crew's composition and training, resulting in the inclusion of two inadequately trained individuals in the crew;
• Insufficient supervision and weak control by the flight and navigation department of the Moscow Civil Aviation Administration over the implementation of key documents and directives of the Civil Aviation Administration to ensure flight safety in the 65th Flight Detachment;
• Technical deficiencies in the landing gear position warning system of the Il-18 aircraft, the primary flaw being the necessity to disable the siren during descent, which also deactivated the landing gear position indicator lights.

References

1. "Ильюшин Ил-18Б Бортовой №: CCCP-75708" [Ilyushin Il-18B Side No.: CCCP-75708] (in Russian). Russianplanes.net. Archived from the original on 2013-05-25. Retrieved 2013-05-22.
2. "Катастрофа Ил-18В Московского ТУ ГА в а/п Внуково" [Disaster Il-18B Moscow TU GA in a / p Vnukovo]. airdisaster.ru (in Russian). Archived from the original on 2013-01-22. Retrieved 2013-05-22.