Accident Overview
A Bell 47G-3B helicopter equipped with a Soloy conversion was being used to demonstrate an aerial application spraying technique for use along powerline right-of-ways. The accident occurred during a routine spray run demonstration.
Flight Details
For approximately 15 to 20 minutes after takeoff, routine spray runs were made over several different powerlines while using water as a spray. Immediately prior to the accident, a spray run was made from west to east with a pull-up and turn-around over powerlines along the east side of the area.
Pilot Statement
The pilot reported that following the turnaround, both the cyclic and collective controls failed to respond, and the helicopter began to vibrate. He stated that the engine was performing satisfactorily and that the rotor RPM was normal.
Witness Observations
Witnesses stated that the helicopter remained in a nose-down attitude until impact with the ground.
Post-Crash Fire and Examination
After the occupants were removed from the wreckage, the helicopter began burning. An examination of the wreckage revealed no preimpact malfunction or failure. However, due to the extent of the fire damage, no useful information was found regarding the flight control, hydraulic, or other systems in the body frame area.