What happened
The pilot was conducting a return flight along the same route as a previous leg when the accident occurred. Radar data recorded two separate transponder-equipped aircraft in the area. The first aircraft was tracked from 19:02:51 to 19:04:07, traveling in a southeast-to-northwest direction at an encoded altitude of 12,600 feet mean sea level (msl).
A second, unidentified aircraft, operating with transponder code 1200, was tracked between 19:07:00 and 19:12:07. This aircraft was flying in a northwest-to-southeast direction at an encoded altitude of 13,600 feet msl. At the time of the accident, the unidentified airplane was estimated to be approximately 14 miles away from the first aircraft.
At 19:04, the first aircraft disappeared from the radarscope. No distress calls were made prior to the disappearance. Air traffic controllers attempted to reestablish radio contact with the pilot between 19:06 and 19:26, but these attempts were unsuccessful. Search and rescue operations were launched, and the wreckage was discovered the following afternoon.
Dark night visual meteorological conditions were present during the event.
The investigation
A metallurgical examination of the wreckage focused on several key components. The fractures found in the left wing, right horizontal stabilator, and vertical stabilizer spar were determined to be consistent with overstress separations. These components failed due to negative loading. The investigation found no evidence of preexisting cracking, such as fatigue or stress corrosion.