Accident Overview
An aircraft involved in an external load agricultural flight crashed following a loss of tail rotor control. Witnesses reported that during a landing attempt at a loading area, the aircraft began spinning. The external load was subsequently jettisoned, and the aircraft struck the ground and rolled over.
Investigation Findings
Examination of the wreckage revealed that the pitch change drum, part number 3160566-00-009-1, was worn throughout its interior aluminum splines. The pitch control drum had been removed on August 9, 1984. According to the aircraft manual, each time the drum is removed, it must be visually checked for wear. Between August 9 and October 29, 1984, the aircraft accumulated 236.9 hours of operating time.