What happened
Shortly after departing, the aircraft type entered a right-hand turn and moved over a large body of water. While the airport environment was characterized by dark night visibility, the flight transitioned into instrument meteorological conditions shortly after takeoff. During the initial climb, the aircraft achieved a climb rate exceeding 6,000 fpm, eventually passing through its assigned altitude of 2,000 feet mean sea level.
As the flight progressed, the flight director issued alerts both before and after the aircraft surpassed its assigned altitude. The aircraft's bank angle increased to approximately 62 degrees, while the pitch attitude dropped to 15 degrees nose down. The bank angle eventually leveled out to 25 degrees, but the aircraft entered a descent where the airspeed reached 300 knots and the descent rate hit 6,000 fpm. The enhanced ground proximity warning system (EGPWS) issued several alerts, including bank angle, sink rate, and seven consecutive pull-up warnings.
Findings
An investigation of the wreckage showed no evidence of mechanical failure or pre-impact malfunction. It is believed the pilot intended to engage the autopilot following takeoff but failed to verify its engagement via the primary flight display. This lack of verification, combined with insufficient instrument scanning during a period of high workload, led to the aircraft deviating from its assigned altitude, heading, and bank angle limits.
Several factors likely contributed to the accident. The pilot may have suffered from spatial disorientation due to the lack of visual references over the lake and the transition into instrument conditions. Additionally, differences in avionics layout between this aircraft and the pilot's previous aircraft may have caused mode confusion. Furthermore, the pilot had been awake for nearly 17 hours, and the resulting fatigue likely impaired the ability to manage the high-workload environment and respond to the EGPWS warnings.