What happened
During the 17th test flight of a prototype bomber, an engine unexpectedly detached from its mounting hardware while the aircraft was airborne. This mechanical failure caused the aircraft to lose stability and enter an uncontrolled dive.
As the plane descended, the crew attempted emergency procedures. Nine members of the flight crew successfully exited the aircraft via parachute before the impact occurred. The wreckage eventually came to rest in a field situated in Noguinsk, approximately 50 km east of Moscow. The accident resulted in three fatalities among the crew.
Findings
Investigations into the crash determined that the primary factor was the physical loss of an engine during flight, which directly led to the subsequent loss of control and the aircraft's descent into the ground.