Accident Sequence
The aircraft was en route at flight level 240 (FL240) when it entered a left spiraling descent. At approximately 7,000 feet, an inflight breakup occurred, resulting in the separation of the outboard wings, tail sections, and internal vinyl from the nose baggage door. No distress call was transmitted. Witnesses reported hearing the engines and an explosive sound, then observing the aircraft in a spin with trailing debris.
Debris and Wreckage
Debris was scattered over an area spanning about 3.5 miles. Lightweight pieces, including vinyl from the baggage door, wing skin, and tail skin segments, were among the first debris found along the wreckage path. The tail sections were located approximately 2.5 miles from the main wreckage, exhibiting evidence of overload failure. Wing fragments also showed evidence of downward/overload separation.
Aircraft Information
The aircraft had been inactive for approximately two years before being purchased two months prior to the accident. The last annual inspection occurred on June 8, 1992. Examination of the airframe revealed no preexisting failures that would have led to loss of control, inflight breakup, loss of pressurization, or hypoxia.
Weather Conditions
Meteorological forecasts indicated icing conditions from 9,000 to 17,000 feet mean sea level (MSL) and turbulence below 8,000 feet MSL. The investigators did not determine whether weather directly affected the flight.
Probable Cause
The official probable cause was the pilot's loss of aircraft control for an unknown reason, and subsequent flight that exceeded the design stress limits of the airplane, which resulted in an in-flight airframe breakup.