CEN21LA184

The pilot was flying over his wheat fields as the wind was from the south at 10 knots. The pilot transitioned to a hover close to the ground and experienced a sudden unanticipated yaw to the left. The helicopter completed more than one full rotation to the left, then landed hard in the field and sustained substantial damage to the main rotor blades and fuselage. Examination of the helicopter and flight control system did not reveal any preimpact mechanical malfunctions or anomalies that would have precluded normal operation. The helicopter manufacturer had previously issued a safety notice for unanticipated yaw, which stated in part, “A pilot's failure to apply proper pedal inputs in response to strong or gusty winds during hover or low-speed flight may result in an unanticipated yaw…To avoid unanticipated yaw, pilots should be aware of conditions (a left crosswind, for example) that may require large or rapid pedal inputs.” Given that the postaccident examination of the helicopter did not reveal any preimpact anomalies and the 10-knot wind at the time of the accident, it is likely that the pilot did not apply adequate pedal input to avoid the loss of yaw control while transitioning to a hover.

On April 5, 2021, at 1700 central daylight time, a Robinson R44 helicopter, N8348X, was substantially damaged when it was involved in an accident near Johnson, Kansas. The pilot and one passenger were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to statements provided by the pilot and pilot-rated passenger, they were using the helicopter to check their wheat fields. The wind was from the south at 10 knots. The pilot executed a hover maneuver close to the ground and experienced a sudden unanticipated yaw to the left. The helicopter completed more than one full rotation to the left, then landed hard in the field and rolled onto its left side. The pilot reported that he was not aware of any mechanical malfunctions with the helicopter. The responding Federal Aviation Administration inspector reported that the helicopter sustained substantial damage to the fuselage and main rotor blades. Examination of the helicopter and flight control system did not reveal any preimpact mechanical malfunctions or anomalies that would have precluded normal operation. The helicopter manufacturer had previously issued a safety notice for unanticipated yaw, which stated in part: A pilot's failure to apply proper pedal inputs in response to strong or gusty winds during hover or low-speed flight may result in an unanticipated yaw…To avoid unanticipated yaw, pilots should be aware of conditions (a left crosswind, for example) that may require large or rapid pedal inputs.