The Li-2T operated on a flight from Kiev to Simferopol with an en route stop at Nikolaev. During the flight, a crew member threw a cigarette stub out of the right cockpit window which entered the air intake of the cabin ventilation system situated behind the cockpit window at the same height. A fire developed in the ventilation system, incinerating the interior lining of the cabin and spreading rapidly as non-impregnated cotton wool had been used as insulation material. As the fire could not be extinguished, the crew initiated an emergency descent and the aircraft made a belly landing in a field near Lipovets. It slid down a slope, collided with trees on the banks of the river Rosava, came to rest on the ice of the river and burnt out. It appeared that the aircraft had been converted from a cargo version to a mixed cargo-passenger version in January 1955. In this process several mistakes were made, a.o. the positioning of the air intake of the cabin ventilation system and the use of non-impregnated insulation material.