What happened
On the morning of the accident, a scheduled service flight, identified as SU558, departed from Karaganda Airport at 08:31 local time. The aircraft, a four-engine airplane, was en route to Moscow-Domodedovo when the crew reported smoke infiltrating both the cockpit and the passenger cabin. In response to the situation, the crew contacted air traffic control to request an emergency diversion to Magnitogorsk Airport.
During the descent phase, while maintaining a speed of 370 km/h, the aircraft struck the ground in an open field situated approximately 23 km north of the destination airport. At the moment of impact, the plane was in a flat attitude with its landing gear and flaps retracted. The collision resulted in a massive fire that consumed the airframe. There were 102 fatalities among the occupants, with no survivors reported.
Findings
Investigations into the disaster determined that an intense fire originated within the rear cargo compartment. This fire spread rapidly, causing significant smoke to fill the cockpit, which obscured the flight instruments and prevented the crew from maintaining visual flight conditions. The severity of the fire led to a loss of control capabilities for the crew.
Investigators identified the fire in the rear cargo hold as the primary factor leading to the crash. The ignition is believed to have been caused by the activation of pyrotechnic devices or the spontaneous combustion of flammable items located within the passenger baggage.