12 fatalities

Engine Failure and Icing Conditions Lead to Crash of Lisunov LI-2 Near Irkutsk (CCCP-L4790)

Irkutsk, RussiaFlight

On March 25, 1951, a Lisunov LI-2 (registration CCCP-L4790) operated by Aeroflot - Russian International Airlines was involved in an aviation accident near Irkutsk, Russia in flight. 12 people were killed. Investigators recorded the probable cause as: The third cylinder of the right engine failed in flight, causing the engine to catch fire. With one engine inoperative and flying in icing conditions and turbulence, the aircraft was unable to maintain height, hit trees, and crashed. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781256630Data APIEditorial standards

A Lisunov LI-2 departed Irkutsk in poor weather, experienced a right engine fire due to cylinder failure, and crashed after striking trees. One passenger survived with serious injuries; 12 others were killed. The wreckage was found 10 days later.

Accident

On an unspecified date, a Lisunov LI-2 aircraft departed Irkutsk Airport at 0431 local time under poor weather conditions. Horizontal visibility was 2 km in snowfall, with a low cloud base, turbulence, and icing conditions. Shortly after departure, the aircraft failed to follow the prescribed flight path. Minutes later, at an altitude of 1,500 meters, the right engine caught fire. The crew feathered the propeller and initiated a return to the airport. Approximately 10 to 15 seconds later, while losing altitude, the aircraft struck tree tops and crashed inverted in a wooded area 4 km north of the village of Iskra, about 20 km east of Irkutsk. The aircraft was destroyed. One passenger was found seriously injured, and 12 other occupants were killed.

Investigation and Probable Cause

The official investigation determined that the third cylinder of the right engine failed in flight, causing the engine to catch fire. With one engine inoperative and operating in icing conditions and turbulence, the aircraft was unable to maintain altitude, struck trees, and crashed. The following factors were considered contributory: lack of visibility due to poor weather; icing conditions and turbulence; poor maintenance of the right engine regarding the 50-hour periodic inspection procedure; poor quality of the third cylinder; improper adjustment of the exhaust valve; the pilot-in-command voluntarily modified the crew before take-off and requested a copilot who was not licensed to fly a Lisunov LI-2 but only a Polikarpov PO-2; the copilot's inexperience on the Lisunov LI-2 prevented him from assisting the captain in a complex flight situation; and the crew was tired and intoxicated after consuming alcohol before takeoff.