Accident
The first prototype of the Cessna 340 aircraft was destroyed in a crash during a local test flight. The pilot, who was the only occupant, departed from Kingman-Clyde Cessna Field. While flying near the airfield, the pilot lost control of the airplane, which subsequently crashed in an open field. The aircraft was destroyed and the pilot was killed.
Investigation
Officials determined that the accident was caused by an uncontrolled descent resulting from a failure of the elevator tab control system. Investigators identified several contributing factors: the elevator tab control system had been improperly installed. There was also improper maintenance, an inadequate preflight preparation, and a separation in flight. Specifically, a bolt that was improperly secured in the elevator trim push-pull rod came out, leading to the loss of the horizontal stabilizer assembly.
Probable Cause
The official probable cause of the accident was an uncontrolled descent caused by the failure of the elevator tab control system. The following factors were reported: elevator tab control system improperly installed; improper maintenance; inadequate preflight preparation; separation in flight; and a bolt improperly secured in the elevator trim push-pull rod that came out and caused the loss of the horizontal stabilizer assembly.