The airplane was substantially damaged during an in-flight breakup at about 1000 Pacific time. The private pilot and passenger sustained fatal injuries.
Visual conditions prevailed in the area around the accident site; the aircraft was being operated on an IFR flight plan.
Preliminary radar data depict the airplane in cruise flight at FL240 and a course of 335 degrees magnetic. At 0937, the airplane’s heading turned to about 320 degrees and oscillated around that value until the last several radar returns indicated the airplane in a descending turn to the right. During the last approximate 30 seconds of flight, the airplane descended from cruise altitude to 14,500 feet msl, which was the last recorded altitude. The main wreckage was separated from sections of tail skin panels by approximately 1500 feet.