What happened
A domestic cargo flight, carrying 2FR pounds of freight, departed following an IFR flight plan and a weather briefing. The flight was proceeding normally while established on the VOR/DME-C approach. Radar monitoring showed the Cessna 208 descending from 10,600 feet toward a crossing altitude of 9,200 feet. During the inbound turn toward the VORTAC, the aircraft's track and altitude began to fluctuate significantly, deviating northwest and southeast before the aircraft disappeared from radar.
At the time of the incident, local weather conditions included a 600-foot overcast, visibility of 1.5 miles in misting rain, and temperatures of 36 degrees Fahrenheit. Environmental reports indicated a high probability of icing conditions and visible moisture in the vicinity. The wreckage was located in the immediate area of the last radar contact. There was no evidence of any mechanical failure regarding the engines, propellers, or the airframe prior to the impact.
Findings
Investigation into the electrical system revealed that the generator off annunciator light had been illuminated. This state suggests the generator had disconnected, potentially due to a tripped circuit breaker, a line surge, or an error in switch operation. It was noted that the proximity of the start switch to the ignition switch could lead to an accidental movement of the switch to the ON position during checklist execution. Such an error would cause the generator to disconnect and serve as a significant distraction to the pilot.
While the pilot was properly certified, he had limited experience with this specific aircraft model, with only 38 hours of flight time. Although the pilot had encountered icing in previous flights, he had no recorded encounters with ice in this specific aircraft, and his simulated instrument time in the Cessna 208 was minimal.