19990415003569A

Pilot was practicing landing the Robinson R-22 helicopter on the beach when the acft lost engine power at 10 feet AGL, landed hard on the sand, and rolled over, other circumstances are unknown. (-23) flight instructor and his student were practicing normal approaches to a hover at a beach in Port Jefferson, nu. The flight instructor indicates that as he pulled collective pitch to bring helicopter into a hover, the aircraft engine did not produce enough power to allow aircraft to hover. Helicopter hit the sand left skid first and rolled over. Flight instructor further states that he did hear low rotor horn sound prior to touch down. (.4) the private pilot was receiving rotorcraft instruction and was on approach to land. As the helicopter passed through about 15 feet, the flight instructor was also on the flight controls. The airspeed was about 20 mph, with a descent of 200-300 fpm. When the collective was raised the helicopter continued to descend, landed hard, and rolled over. When interviewed the flight instructor remembered the low rotor warning horn had sounded. Post accident examination of the engine and mechanical throttle compensator found n o evidence of a mechanical failure. The helicopter manufacturer had published a safety notice which cautioned against airspeed of less than 30 knots until the descent rates were less than 300 fpm.