Flight History
On 03.10.2019, the crew of An-12BK UR-CAH, operated by PJSC AIRLINE UKRAINE-AIR ALLIANCE, performed flight UKL4010 from Toronto (Canada) to Toulouse (France), landing at 06:15 UTC with 1537 kg of cargo. After post-flight procedures, the flight crew rested at a hotel while two aircraft technicians remained on the aircraft for maintenance. The next flight was scheduled to Birmingham (Great Britain), but the operator changed the route to Toulouse – Vigo (Spain) – Istanbul (Turkey). In Toulouse, 6,000 liters of fuel were added and a flight engineer was replaced. At 16:16 UTC, the aircraft departed for Vigo without cargo, landing at 18:20 UTC on 03.10.2020 (source date). At Vigo, vehicle spare parts were loaded, with a total weight of probably 14,078 kg. The aircraft departed Vigo on 03.10.2019 at 22:20 UTC for flight UKL4050, with a 2-hour 20-minute delay.
Accident Sequence
On 04.10.2020 (source date), at 03:17:29 UTC, the aircraft approached the Lviv control area airspace border. The crew contacted Lviv ACC and reported approaching waypoint MALBE at FL250. Controller issued radar guidance for an ILS approach to runway 31. ATIS Romeo informed visibility 150 meters, vertical visibility 50 meters, fog, and RVR 550 meters. At 03:22:14, the crew acknowledged and was cleared to FL120. Descent began at 03:22:40. At 03:30:14, radar guidance began. The controller issued descent to 4,000 feet at 03:32:49 and later to 3,200 feet with temperature correction. At 03:38:33, the controller gave a left turn to heading 340°, cleared the ILS approach to runway 31, and asked to report localizer capture. At 03:40:01 (height 1,170 m, distance 15.7 km), the crew reported capture. Weather updated: RVR 800 m, vertical visibility 60 m, fog. At 03:41:22, the crew switched to Tower frequency. The aircraft was below the glide path; at 7.58 km from touchdown, it was 11 m below glide path with descent rate 4.5–5.5 m/s, speed 290 km/h. At 5 km, it was 25 m below. At 3 km, altitude 105 m. At 60 m, the decision height alarm sounded; no crew response. At 1,348 m from runway threshold, at 5–7 m altitude, the aircraft collided with trees, fell to the ground, and came to rest 1,117 m from the threshold. All three passengers were seriously injured; all five crew members were killed.
Probable Cause
The probable cause of the accident was the crew’s failure to perform the flight in instrument conditions due to probable physical excessive fatigue, leading to an unconscious descent below the glide path and ground impact (controlled flight into terrain). Contributing factors included probable exceeding of takeoff weight at Vigo, which could increase fuel consumption and prevent diversion to the alternate Boryspil aerodrome.