Accident Details
On July 6, 2013, at approximately 1110 central daylight time, a Bell 47G-3B-1 helicopter, registration N7924S, sustained substantial damage when it struck terrain during an agricultural aerial application flight near Plover, Wisconsin. The helicopter was operated by Reabe Spraying Service under 14 Code of Federal Regulations Part 137 and was registered to 102 Leasing LLC. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight originated from a private airstrip near Plover, Wisconsin, about 1105.
Pilot Account
The pilot, the sole occupant, sustained minor injuries. He reported that he was finishing the field after having flown approximately 5 hours of aerial application flights earlier that day. On the accident flight, the helicopter was fueled with about half a tank of fuel and about 4 gallons of pesticide. He completed the last pass along the west side of the field traveling to the north. He then turned to the southeast and completed spraying a short segment of the field. He pulled up and performed a 180-degree turn to the right. During the turn, the engine and rotor rpm were about 2,000 rpm when he started to reapply power. As he rolled out of the turn, the helicopter impacted the field.
Post-Accident Examination
Federal Aviation Administration (FAA) inspectors examined the helicopter and determined that the collective, cyclic, and anti-torque pedals exhibited flight control continuity. Examination of the engine's fuel system and ignition system revealed no anomalies. A compression test showed that all six cylinders had normal compression readings. Both the main rotor tachometer and engine tachometer were checked and found operational. A teardown of the engine was conducted, and no anomalies were noted that would have prevented normal operation.
Pilot Interview
During an interview with an FAA inspector, the pilot reported that the engine was at 3,200 rpm (full power) during takeoff. During the course reversal turn, the engine was about 2,000 rpm, and he was reapplying power back to 3,200 rpm during the rollout when the helicopter impacted the field.