Accident Overview
A flight instructor and a student pilot were conducting hover practice in a grassy area adjacent to a taxiway at an airport. During the exercise, the helicopter ascended to approximately 20 feet above ground level. The instructor then advised the student to reduce altitude.
Descent and Loss of Control
According to the instructor, the helicopter subsequently entered a high rate of descent that could not be arrested before ground contact. He further stated that the helicopter developed a dynamic rolling moment that full down collective input was unable to counteract.
Impact and Damage
The helicopter rolled onto its left side and came to rest in that attitude. The accident resulted in substantial damage to the tail boom, skids, and main rotor system.
Environmental Conditions
At the time of the accident, the reported wind at the airport was from 250 degrees at 13 knots, gusting to 17 knots.
Pilot Report
The instructor did not report any mechanical anomalies with the helicopter.