Accident Summary
A helicopter conducting an introductory flight for a student experienced a loss of control during a hover exercise, culminating in the main rotor blades striking the ground. The event occurred after the student pulled the collective and cyclic controls from the instructor's hands and subsequently let go.
Flight Sequence
The purpose of the flight was to provide a student with an introductory aviation experience. After completing a local flight, the helicopter returned to the airport for hover work. The aircraft then air taxied to a point just short of a runway, where the pilot anticipated crossing. While waiting to cross, the instructor established a hover and tasked the student with attempting to hold the helicopter steady. The instructor kept his hands on the controls during this exercise. At some point, the student "pulled the controls" from the instructor's hands. Moments later, the instructor realized that the student had let go of the controls.
Loss of Control
Following the student's release of the controls, the helicopter "rolled hard left, very fast." The instructor was unable to regain control before the main rotor blades contacted the ground.
Examination Findings
A post-accident examination of the helicopter revealed no evidence of any preimpact malfunctions. The aircraft's systems and components were found to be in normal operating condition prior to the event.
Conclusion
The accident occurred as a result of a loss of control during a hover training maneuver. The sequence of events—student pulling controls from the instructor, then releasing them—led to a rapid, uncommanded roll and subsequent ground contact of the main rotor blades. No direct causal statement is provided in the source material beyond the factual sequence.