According to the flight instructor, his student was practicing hover operations over a grassy area of the airport. This was the first flight in a helicopter for the student pilot. The helicopter drifted to the right while descending. The right skid contacted the grass and the helicopter rolled to the right and the main rotor blades contacted the ground. The helicopter continued to roll over and came to rest on its right side. An inspector from the Federal Aviation Administration examined the helicopter and confirmed substantial damage to the fuselage, tail boom, and main rotor blades. The pilots reported no pre-impact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.