Bell 206B N52Q accident near Hanford, California

Probable cause

The pilot's decision to release the collective while flying at 10 feet above ground level, resulting in the rapid helicopter descent and impact with terrain.

NTSB analysis

According to the pilot, he was performing a rehearsal 14 Code of Federal Regulations Part 137 flight, during which he was familiarizing himself with the helicopter's Satlock aerial application system. He reported that while flying at the airspeed of about 60 miles per hour, at 10 feet above ground level, he removed his hand from the collective in order to advance to the next screen on the Satlock display. He recounted that the collective decreased which subsequently decreased themain rotor blade angle and decreased the engine power; the helicopter descended, impacted the terrain, and rolled several times before coming to rest. The helicopter sustained substantial damage to the frame, rotor systems and the power train.

The pilot reported that there were no mechanical failures or anomalies with the helicopter prior to or during the flight that would have prevented normal flight operation.

Text from the NTSB. Open the NTSB docket for GAA16CA165 for the full record.