What happened
During the initial 15 minutes of the flight, the pilot of the high-performance jet demonstrated difficulty adhering to assigned altitudes and headings. The pilot also showed intermittent responsiveness to air traffic control instructions. Upon reaching 27,000 feet, the aircraft began a rightward deviation of approximately 30 degrees while in a climb. Despite alerts from air traffic controllers, the pilot did not respond, and the aircraft continued its ascent.
Two minutes later, the aircraft entered a tight, spiraling descent. This maneuver lasted for eight minutes before the aircraft struck the ground at high speed in a rightwing-low attitude. The impact caused the aircraft to become highly fragmented. Post-accident investigations confirmed that both engines were producing power at the time of impact, and there was no evidence of bird strikes, in-flight fire, cabin depressurization, or structural failure.
Findings
Investigation into the pilot's background revealed that while the pilot was experienced in various aircraft, he lacked a specific type rating for this jet and was likely flying the aircraft solo for the first time. Although training had been initiated two months prior, it was never completed. During previous training sessions, the pilot struggled with the aircraft's newly installed avionics suite and performed poorly in high-workload scenarios. Evidence suggests the pilot preferred manual flight over using the autopilot.
Analysis of the flight path prior to the spiral indicated the pilot was likely not utilizing the autopilot. During the final spiraling descent, speed variations were consistent with the aircraft's open loop phugoid response, suggesting the pilot was likely not manipulating the flight controls during the terminal phase of the flight.