What happened
A cargo and military transport flight was operating a route originating in Aden, with a scheduled stop in Karachi before proceeding to its final destination in Tashkent. During the second leg of the journey, while cruising at an altitude of 5,500 meters, the aircraft encountered severe turbulence and intense hailstorms.
As the weather conditions worsened, all four engines experienced a simultaneous loss of power. In response to the engine failures, the crew performed necessary shutdowns of engines number 1 and 3, while reducing engines number 2 and 4 to idle settings. During the subsequent emergency descent, the aircraft suffered partial structural failure in mid-air before impacting the ground.
Findings
Investigations into the accident revealed that the primary driver of the engine failures was the accumulation of hail within the oil tanks. This buildup led to the loss of power across all four engines. Additionally, it was determined that excessive g-loads experienced during the emergency descent caused various components of the aircraft to detach from the airframe.