What happened
During a scheduled training mission originating from Castle AFB, the flight crew performed a simulated emergency descent. The aircraft descended from an initial altitude of FL390 down to FL230. Following this procedure, the pilot-in-command executed a sharp turn, at which point the aircraft experienced a sudden loss of control. The aircraft type impacted the terrain on Mount Lassen, resulting in the total destruction of the plane.
There were nine fatalities among the crew members involved in the accident.
Findings
Investigations into the crash determined that the primary factor was the physical separation of the stabilizer. This component detached from the aircraft during the high-stress maneuver, which led to the subsequent loss of control.