What happened
A training flight operated by the United Air Lines Flight Training Center departed from Stapleton Airfield at 06:55 local time. The crew of United Trainer 16, which included a senior instructor and two trainee first officers, was conducting a scheduled four-hour training mission within a 25-mile radius of Denver. At the time of departure, weather conditions were favorable, with unlimited visibility and winds from the northwest at 16 knots.
The aircraft, a training aircraft, was configured with 820 gallons of fuel, full oil tanks, and 650 pounds of sand ballast located in the rear baggage compartment. The takeoff weight of 22,910 pounds was within legal limits, and the center of gravity was properly maintained. Following the departure announcement, the aircraft failed to make further radio contact with air traffic control.
Between 07:20 and 07:25, observers witnessed the aircraft enter a stall and subsequently transition into a spin. The plane descended in a diving attitude before striking the ground. There were 0 fatalities reported in this incident.
Findings
Investigations into the wreckage revealed no evidence of mechanical failure or component malfunction prior to the impact. Both engines were producing power at the moment of the crash. The aircraft had stalled at an altitude of approximately 8,200 feet MSL, which placed it roughly 3,200 feet above the terrain. The investigation concluded that the primary factor was an inadvertent spin occurring at an altitude too low to allow for recovery.