Propeller/rotor malfunction involving a Air Tractor Inc AT-301, VH-JFA, Coleambally, NSW on 19 March 1993

During agricultural operations, one propeller blade moved to coarse pitch while the aircraft was flying at a height of 50 feet. Power was reduced, the load dumped and the pilot carried out a forced landing in a nearby paddock. Investigation revealed that one counterweight roller bearing shaft had failed in fatigue across the split-pin hole. The split-pin hole is drilled close to where the bearing shaft exits the hub flange. The hub has now been modified to locate the split-pin in the threaded section at the opposite end of the shaft.