Accident Overview
On March 26, 2021, about 1515 central daylight time, a Robinson Helicopter Company R44 II, registration N178DF, was substantially damaged in an accident near Dustin, Oklahoma. The helicopter was operating as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. The private pilot and one passenger received serious injuries, while two passengers received minor injuries.
Pilot Account
The pilot reported that while maneuvering "low and slow" with three passengers on board, he noticed "insufficient power." Shortly thereafter, the low rotor rpm warning annunciated. He applied full throttle and attempted to regain rotor rpm but was unsuccessful. The pilot stated that he was forced to land the helicopter immediately. During the landing, the helicopter impacted a tree and then terrain, resulting in substantial damage to the main rotor, fuselage, and tailboom.
Examination
The pilot reported that there were no mechanical malfunctions or failures with the helicopter and recommended operating "at a lower gross weight." Postaccident examination of the helicopter revealed no anomalies that would have precluded normal operation.