Accident Details
While cruising at 1,500 meters in marginal weather conditions, an aircraft traveling from Aktyubinsk to Uralsk was hit by lightning. The crew lost control, and the aircraft dove into the ground, crashing in a field 4 kilometers southeast of Konstantinovski in the Aktyubinsk region. The wreckage was discovered several hours later. All 27 occupants were killed.
Investigation Findings
The official investigation determined that the lightning strike caused a discharge through the port control cables of the left aileron, located on the left wing behind the rear spar of the center wing between the fourth and fifth sections. This resulted in the crew being paralyzed or in a state of shock, with instant loss of aircraft control.
Several contributing factors were identified: presence of thunderstorm activity; overheating and rupture of the left aileron control cables due to high temperatures; the crew's inability to send a distress call; a quick, uncontrollable dive at excessive speed; the crew's inability to attempt an emergency landing in night conditions; and failures in weather reporting. Specifically, employees at the meteorological station in Aktyubinsk did not indicate any thunderstorm in the forecast, while an observer at the Novoalekseevka weather station noted a thunderstorm but failed to report it to the Aktyubinsk station, violating published procedures.