1979 Dniprodzerzhynsk mid-air collision

On 11 August 1979, a mid-air collision occurred over the Ukrainian SSR, near the city of Dniprodzerzhynsk (now Kamianske). The aircraft involved were both Tupolev Tu-134As on scheduled domestic passenger flights, operated by Aeroflot. All 178 people aboard both aircraft died in the accident.

The official Soviet aviation board investigation of the accident concluded that the crash was caused by "mistakes and violations" made by air traffic controllers.

Accident sequence

Flight 7628 was flying on Airway 50 (Magdalinovka – Ball, course 201°) and Flight 7880 was on Airway 147 corridor (Dnipropetrovsk – Kremenchuk, course 300°). These corridors intersect at an angle of 99° north-east of Dniprodzerzhynsk. Because of previous errors, the controller's perception of the location of each aircraft was incorrect. When the ATC supervisor heard the radio traffic and saw the aircraft converging on the radar screen he realized the catastrophic situation and attempted to correct it. At 13:34:07 the ATC controller ordered aircraft 86676 (IL-62) from 9000 to 9,600 m. At 13:34:21 ATC controller repeated the order and then directed Flight 7880 from 8400 meters to the now vacant altitude at 9000 m.

13:34:07 ATC to aircraft 86676 "Take 9600."

13:34:21 ATC to aircraft 86676 "Take 9600."

13:34:23 ATC to Flight 7880 "and you take a 9. Over 8400 Dneprodzerzhinsk crossover."

13:34:25 aircraft 86676 to ATC "9600."

13:34:33 (inaudible.) "Got it... 8400"

The controller heard a muffled reply and assumed it was an acknowledgement from Flight 7880 – but the muffled transmission was actually from aircraft 86676 and Flight 7880 remained at 8400 meters.

Collision

Flight 7628 had strayed to the left of the airway by approximately 4 km, while Flight 7880 was to the left by 0.5 km. At 13:35:38 both aircraft suddenly disappeared from ATC radar screens. Zhukovsky tried to contact them, but they did not respond. At 13:37, Igor Chernov, the captain of an Antonov An-2 (CCCP-91734) flying from Cherkasy to Donetsk, reported "Something is falling from the sky!" At 13:40 Chernov reported seeing aircraft parts in the area of Dniprodzerzhynsk (now Kamianske).

Both aircraft collided in a cloud at an altitude of 8400 m, approximately over Dniprodzerzhynsk. Flight 7880's right wing sliced through Flight 7628's forward fuselage, tearing off part of 7880's right wing, the debris of which was ingested by 7880's right engine. The impact spun 7628 to the right, causing the tails of both aircraft to collide at which time the left engine of 7628 struck the keel of 7880, and 7628's right wing was torn off. Flight 7628 tumbled out of control and broke up, with debris scattered over an area measuring 16 by 3 km. Damage to 7880 included the loss of most of the empennage, one of the engines and a section of the right wing. The pilots of 7880 attempted an emergency landing, but at an altitude of approximately 4000 m they lost control and at 13:38 crashed north-east of Dniprodzerzhynsk, completely destroying the aircraft.