Investigation Details
On the date of the accident, an aircraft impacted terrain in an uncontrolled descent at an elevation of 2100 feet MSL. Examination of the wreckage revealed that the horizontal stabilizer and left wing had separated from the aircraft. The outboard section of the left wing was not located during the inspection. Metallurgical analysis of the remaining portion of the left wing spar indicated a failure described as "typical of overstress."
Witness Account
A witness located approximately 3 miles southeast of the accident site reported hearing the aircraft "rev up to a scream followed by a crash that sounded like a miniature sonic boom." The witness's observation supports the sequence of events leading to the ground impact.
Weather Conditions
The nearest weather reporting station, Troutdale, Oregon, situated 13 nautical miles southwest of the accident location at an elevation of 30 feet MSL, issued a meteorological observation at 1845 PDT. The conditions included 2500-foot scattered clouds, a 4000-foot overcast ceiling, and visibility of 20 statute miles.
Findings
The investigation found that the aircraft sustained a structural failure in flight, with the horizontal stabilizer and left wing separating. The left wing spar exhibited overstress characteristics, indicating that the failure occurred under loads exceeding the structural limits. The missing outboard left wing section precluded further examination. No additional factors were identified from the available evidence.