Ukraine Air Alliance flight 4050, an Antonov An-12, crashed on approach to Lviv International Airport, Ukraine. The aircraft departed Vigo Airport, Spain about 22:20 UTC on October 3 on a flight carrying 13000 kgs of automobile spare parts to Bursa, Turkey. A refueling stop was planned at Lviv, Ukraine. At 03:20 UTC (06:20 local time) the flight entered the airspace of Ukraine and the crew listened to the ATIS frequency to obtain the latest weather information. Low visibility procedures were in force at Lviv, with runway 31 in use for ILS approaches. Fog had reduced the visibility at the touchdown zone to 150 meters with a vertical visibility of 50 m. At 03:40 the flight reported capturing the localizer and the controller reported visibility had increased to 800 m at the touchdown zone and a vertical visibility of 60 m. After the flight was cleared to land, the aircraft descended significantly below the glide slope. At a distance of 3,3 km from the runway, the aircraft had descended to an altitude of 100 meters. At an altitude of 60 meters, an alarm sounded that the decision height had been reached, to which no crew member responded. At a distance of 1359 meters from the runway threshold, at an altitude of 5-7 meters, the aircraft collided with trees and crashed. Causes The most probable cause of the accident, collision of a serviceable aircraft with the ground during the landing approach in a dense fog, was the crew’s failure to perform the flight in the instrument conditions due to the probable physical excessive fatigue, which led to an unconscious descent of the aircraft below the glide path and ground impact. Contributing Factors Probable exceeding the aircraft takeoff weight during departure from the Vigo Airport, which could result in increase in consumption of the fuel, the remainder of which did not allow to perform the flight to the alternate Boryspil aerodrome.