Incident Details
During an aerial work operation spreading superphosphate, a Fletcher aircraft experienced an elevator control issue after its 35th sortie of the day. The pilot reported to the loader driver that the elevator was sticking and tending to jam when the control column was pulled back near the stop. The loader driver crawled inside the rear fuselage and visually inspected the elevator cables and pulleys as the pilot operated the controls. A small curl of 16-gauge metal, approximately 1/4 inch high, was found in the lower elevator pulley and removed. The pilot confirmed satisfactory operation, and flying resumed.
Collision with Terrain
At 10:15, the loader driver noticed the aircraft's noise had ceased. Looking around, he saw the Fletcher lying wrecked on the summit of a ridge. The aircraft had dived into the ground at an attitude slightly over the vertical. All wreckage, except the nose wheel, was confined to the immediate impact area. A witness mark on the airspeed indicator showed impact at 127 mph. There was no fire. The pilot, Trevor Robert Wilson, was killed.
Investigation Findings
The investigation established the integrity of the rudder and aileron systems. The upper elevator cable was intact, but the lower cable was severed 12 inches from the eyebolt attachment to the counterbalance. A loose No. 6 PK screw was found in the lower elevator pulley groove. When the aircraft was in a slight nose-down attitude, the pilot applied back pressure to raise the nose. The screw jammed between the cable and the pulley guard pin, locking the elevator. The pilot's attempt to recover from the steepening dive generated sufficient pressure for the sharp edge of the screw head to sever the cable.