Accident Sequence
A witness located northeast of the accident site reported observing the airplane in an unusual maneuver. According to the witness, the airplane “starting a vertical climb, slowly rolling over and diving straight down.” The witness added that the airplane “never appeared to be trying to pull out of the dive.” The airplane then disappeared from view behind a mountain, and the witness heard the “sound of impact.”
Wreckage Examination
Examination of the wreckage revealed a screwdriver located in the aft section of the fuselage. Investigators observed multiple witness marks around the elevator bellcrank housing, as well as numerous gouges on the screwdriver. When the screwdriver was placed between the elevator bellcrank and housing and the bellcrank moved by hand, the elevator control was restricted to the neutral position.
Laboratory Analysis
Energy dispersive X-ray spectroscopy (EDS) analysis performed on the screwdriver conclusively demonstrated that the screwdriver was lodged between various structural items.