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 Soviet aviation board investigating the accident concluded that the crash was caused by "mistakes and violations" made by air traffic controllers.
Flight history
Aeroflot Flight 7628
Aeroflot Flight 7628 was a twin turbofan Tu-134 passenger jet, serial number 4352210 and registration CCCP-65816, that was built at the Kharkiv Aviation Plant in 1974 and which carried out its first flight on 24 March of that year. It was operated by the airline's Moldova division and at the time of the accident had logged 12,739 hours and completed 7683 takeoff-landing cycles.
There were 88 passengers and six crew members on board the Tupolev airliner.
Aeroflot Flight 7880
Aeroflot Flight 7880 was a Tu-134AK airliner, serial number 1351405 and registration CCCP-65735, that was completed at the Kharkiv aviation plant on 5 November 1971 and which made its first flight later that year. First operated as a "K" model with luxury salons and first-class accommodation, it was later converted to a standard 78- passenger configuration. At the time of the accident, the aircraft had accumulated 10,753 flight hours through 7075 cycles.
There were 77 passengers and seven crew members on board the aircraft. Passengers included personnel of the Pakhtakor Football Club.
Air traffic control
En route to their destinations both aircraft passed through the Kharkiv regional air traffic control (ATC) center airspace. This area was characterized by high traffic density and air traffic controllers often had to carry more than a dozen aircraft simultaneously. This problem had been discussed since the early 1970s, but by the end of the decade the problem had not been solved. The southwest sector, covering from 180° to 255° was especially complex and unpredictable.
On 11 August 1979, at 07:50 MSK a new shift of air traffic controllers began work, headed by Sergei Sergeev. In the difficult southwest sector he employed an inexperienced 3rd-class controller, 20-year-old Nikolai Zhukovsky, under the supervision of 1st-class controller, 28-year-old Vladimir Alexandrovich Sumy.
Adding to the situation that day was that Leonid Brezhnev was embarking on a trip to Crimea. Authorities wanted to give the Soviet leader a clear flight path and this caused considerable disruption of the airline flight operations in the area.
Accident sequence
At 12:54, Flight 7628 took off from Voronezh airport on the last leg of a domestic scheduled route from Chelyabinsk to Voronezh, then to Kishinev.
At 13:11, Flight 7880 departed Donetsk airport bound for Minsk.
At 13:17:15, Flight 7628 contacted ATC to report it was at flight level (FL) and requested permission to climb to FL . Flight 7628 also informed ATC it would reach the Volchansk waypoint at 13:22 and the Krasnohrad waypoint at 13:28, but the controller incorrectly recorded 13:19 to 13:26 respectively, which placed the aircraft ahead of schedule.
At 13:21:43, Flight 7628 re-contacted the ATC center and again requested permission to climb up to 9600 meters, but ATC rejected that request.
At 13:25:48, Flight 7880 bound for Minsk, informed ATC they had departed Donetsk 14 minutes before and were at , and that they would reach the Dnipropetrovsk (now the city Dnipro) waypoint at 13:34 and the Kremenchuk waypoint at 13:44. ATC confirmed the location of the aircraft and ordered them to climb to and maintain .
At 13:27:50, Flight 7628 contacted ATC and reported that they were over Krasnohrad at FL . Flight 7628 then asked controller Zhukovsky for their ground speed and the speed of another Tu-134A identified as 65132, flying at FL . Flight 7628 was flying at and aircraft 65132 was at . Because of the speed difference ATC refused to let flight 7628 climb to 9600 metres. Flight 7628 confirmed the instructions, although they tried to clarify that they could also slow down after the climb. This was the last radio transmission from Flight 7628.