Incident Overview
A certificated flight instructor (CFI) reported that a training flight ended with a loss of control when a hover autorotation was initiated without proper communication. The helicopter subsequently spun and rolled. The CFI stated that there were no pre-impact mechanical malfunctions or failures with the helicopter.
Flight Details
The purpose of the flight was to provide student pilot training. The student pilot had completed several approaches and a practice hover autorotation. The helicopter was then repositioned to a different area of the airport to perform additional hover autorotations. The CFI continued to guard the flight controls during this time.
Maneuver and Sequence of Events
The CFI deviated from the normal procedure of communicating and counting down before rolling the throttle to the closed position. Instead, the CFI initiated the hover autorotation without any communication. In response to the throttle movement, the student pilot depressed the left anti-torque pedal, which the CFI described as improper. The helicopter began to spin. The CFI was unable to regain control, and the helicopter rolled.
Instructor's Remarks
The CFI stated that the accident could have been prevented if he had briefed the student more thoroughly on the maneuver and if he had assumed authority of the controls earlier in the maneuver. The CFI also reiterated that no mechanical issues were present before the accident.