What happened
During a night cargo operation conducted under Instrument Flight Rules (IFR), the flight crew encountered difficulties with the aircraft's transponder settings shortly after departure. The tower controller initially notified the pilot that the transode code being transmitted was incorrect. Although the pilot attempted to rectify the setting, the error persisted until the pilot identified that the wrong transponder unit had been selected and subsequently switched to the proper one.
During this period of distraction, the aircraft deviated approximately 30 degrees to the right of its assigned course. The pilot managed to stabilize the heading while communicating with the departure controller. Following instructions to continue the climb and execute a 120-degree left turn, the aircraft reached an altitude of approximately 4,700 feet AGL. While the pilot was being instructed to perform an additional 20-degree left turn, the aircraft began a right-hand turn and entered a rapid, uncontrolled descent.
The aircraft eventually struck the ground in a nose-down attitude of more than 45 degrees, nearly level with the wings. At the time of the impact, the aircraft was on a heading roughly 220 degrees offset from its previous stabilized flight path. The accident resulted in 0 survivors.
Findings
Investigators found no evidence of mechanical issues involving the engines, airframe, or control systems that would have prevented the aircraft from maintaining normal flight. Due to the extreme energy released during the high-speed impact with the terrain, investigators were unable to obtain toxicological or autopsy results for the crew. Ultimately, the specific event that triggered the sudden right turn and subsequent descent could not be identified.