Ilyushin II-12 accident at Polukotelnikovo, Russia, 20 Aug 1949 (CCCP-L1434)
On August 20, 1949, an Ilyushin II-12 (registration CCCP-L1434) operated by Aeroflot - Russian International Airlines was involved in an aviation accident near Polukotelnikovo, Russia in flight. 8 people were killed. Investigators recorded the probable cause as: Loss of control due to heavy turbulences encountered in thunderstorm activity. It was reported that all informations transmitted to the crew from the meteorological services were unsuitable and did not reflect the truth. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 7 related events involving the same aircraft type or operator are linked below.
Probable cause
Loss of control due to heavy turbulences encountered in thunderstorm activity. It was reported that all informations transmitted to the crew from the meteorological services were unsuitable and did not reflect the truth. There was a lack of organisation by the meteorological services and lack of seriousness in the weather prediction.
— NTSB Determination
Accident narrative
The crew departed Kharkiv Airport in the afternoon bound to the north at an assigned altitude of 1,200 meters. While arriving in the region of Belgorod, the crew encountered poor weather conditions with heavy rain falls and turbulences. The crew modified his route several times to avoid the cloud and the thunderstorm activity and the captain decided to reduce his altitude to 400 meters to fly below the cloud layer. After 45 minutes, the aircraft encountered heavy turbulences, went to a nose down attitude and eventually crashed at a speed of 360 km/h in a field. Three crew members and five passengers were killed while three other occupants were seriously injured. The aircraft was destroyed.
Probable cause (official findings): Loss of control due to heavy turbulences encountered in thunderstorm activity. It was reported that all informations transmitted to the crew from the meteorological services were unsuitable and did not reflect the truth. There was a lack of organisation by the meteorological services and lack of seriousness in the weather prediction.