The aircraft was registered with the tail number CCCP-Л1791 and was delivered to the Main Directorate of Civil Air Fleet under the USSR Council of Ministers, which assigned it to the 1st separate aviation group of the Civil Air Fleet based at Vnukovo.

[2] Over Novosibirsk, the sky was completely covered with clouds, there was heavy rain with hail, strong gusty winds, and visibility dropped to 100–200 meters.

It is likely that lightning struck the aircraft, incapacitating some of the crew members, causing the first officer and radio operator to lose consciousness, while the captain and flight engineer panicked, poorly monitoring the instruments.

Disoriented during flight through the rain and not monitoring the instruments, the captain began to descend south and then southeast until the aircraft crashed into the ground.

[2] The commission concluded that the immediate cause was the entry into a thunderstorm cloud and the incapacitation of two crew members due to lightning.

In the conditions of rain and hail, the remaining two crew members were disoriented, and likely due to panic, did not monitor the instruments or maintain a safe altitude.