Primary finding
Probable cause
An inadvertent stall.
Investigator assessment
Analysis narrative
The pilot was maneuvering along the pipeline attempting to locate what he had thought was a possible leak. He made several attempts to locate the leak and finally radioed to the repair crews on the ground to go to their next job. A witness reported that the airplane circled several times and flew lower each time. During the last pass, the airplane was below the tree line and made a climbing left turn with an 'acute angle up' just prior to the descent to impact.
Source record
Factual narrative
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