Accident Overview
A rotorcraft being used for external load operations with a fertilizer bucket experienced an unusual sequence of events while the pilot was troubleshooting a hydraulic issue. The pilot had landed the helicopter after the hydraulically operated bucket stopped dispensing fertilizer, intending to diagnose the problem. No ground handling crewman was available to assist. While the engine was running at near-maximum rpm to drive the hydraulic pump at full output, the pilot exited the left seat and stood on the left skid to read an externally mounted hydraulic pressure gauge.
Sequence of Events
During egress from the cockpit, the pilot inadvertently bumped the collective control, moving it to the "increase rotor pitch" position. This caused the rotorcraft to become airborne without the pilot aboard. The helicopter climbed to an altitude of about 500 feet above ground level and entered a circling flight path. As it continued, the loaded fertilizer bucket began to swing with ever-divergent oscillations, leading to instability. The increasing oscillations ultimately resulted in a collision between the main rotor and the boom, causing the aircraft to crash.
The source provides no further details on injuries, damage, or subsequent actions.
Probable Cause
(The source does not explicitly state a probable cause.)