Flight Details
The flight was conducted as an on-demand nonscheduled domestic cargo operation. The pilot obtained a standard weather briefing and filed an IFR flight plan before departing at 2228.
Sequence of Events
At 2320, after being cleared to descend from 13,000 to 11,000 feet, the pilot was further cleared to descend to 9,000 feet, stating, "starting to pickup some ice, here." At 2329, the controller observed the aircraft reversing course and inquired about the maneuver. The pilot responded, "I'm not sure. My instruments are going bad." Shortly thereafter, radio and radar contact were lost. The aircraft subsequently struck the ground in a near-vertical attitude.
Investigation Findings
Examination revealed that no avionics, instruments, or vacuum pumps were recovered intact. Investigators found no evidence of preimpact failure or malfunction of the airframe, powerplant, propeller, or flight controls.