The Deceptive Cloud

On Friday, May 13, 1949, an Aeroflot Ilyushin Il-12 was operating a passenger flight from Moscow to Krasnoyarsk. The aircraft was almost brand new - it had been built just two months earlier and had logged only 51 flight hours by the time of the events described here. There were 20 passengers and 5 crew members on board.

The flight included several intermediate stops. One of them was in Omsk, and the next was supposed to be Novosibirsk. In Omsk, the controller received a thunderstorm warning for Novosibirsk, but failed to pass this information on to the crew and cleared the aircraft for departure without concern. After reaching the city, the pilots began requesting entry into the airport zone, but communications were poor because of the severe thunderstorm. At that time, the sky over Novosibirsk was completely overcast, with heavy rain and hail, strong squally winds, and visibility dropping to just 100-200 meters.

While waiting for better radio contact, the crew began circling. The airport did not respond until an hour later. The controller then cleared the aircraft to begin its approach and descend to 700 meters. Two minutes later, a message came from the aircraft: “Entered a little cloud, occasionally can see the ground.” It was the last transmission.

That “little cloud” turned out to be the rear section of a powerful thunderstorm cell. The aircraft was violently tossed up and down and from side to side. At that moment, the co-pilot and the radio operator lost consciousness. It would later be determined that, with a high degree of probability, this happened because the aircraft had been struck by lightning. At the same time, the unconscious co-pilot was gripping the control column. The captain and the flight engineer panicked and stopped monitoring the instruments.

The captain decided to get out of the storm as quickly as possible and made a sharp descending turn. In a steep bank, the aircraft descended to about 85 meters, where it emerged from the cloud, only to run into torrential rain, large hail, and violent squalls. The aircraft was 12 kilometers from the airfield, but the captain had become disoriented and was no longer watching the instruments. He also could not fully control the aircraft because the control column was being jammed by the unconscious co-pilot. As a result, the plane continued descending in a steep bank until it crashed into an embankment. The Il-12 broke apart and caught fire. All 25 people on board were killed.

The investigation commission concluded that the immediate cause of the crash was the aircraft’s entry into a thunderstorm cloud, as well as the lightning strike that incapacitated the co-pilot and the radio operator. The two remaining crew members panicked, while the rain and hail completely disoriented them.

The thunderstorm had not been included in the weather forecast, and the cloud’s rear section did not appear especially dangerous, which became one of the factors in the disaster. The investigation also identified failures in flight management and oversight, including unstable radio communications, the crew not being warned about thunderstorm conditions, and poor coordination between the meteorological services of the airports along the route.