19990601006239A

Crashed on takeoff. Other circumstance unknown. (-23) the airman picked the helicopter into a hover and pointed the ship into the light and variable wind. After a cyclic turn to the left and preparing to exit downhill. The wind shifted to a tail wind, and the surrounding terrain also caused a down draft. The airman applied more power, and the low RPM horn sounded. At that point the pilot stated that he was committed to a takeoff and that another down draft caused the helicopters performance to deteriorate. With the combination of low rotor RPM, 4200 foot MSL takeoff elevation, a down draft, alder bushes creating drag, the helicopter struck the left skid and rolled on it's side striking the main rotor blade on the hillside. The pilot and passenger exited the ship without any injury. (.4) the certificated commercial helicopter pilot reported that during a northerly departure from atop a 4,200 feet MSL mountain, the rotor RPM dropped, and the low rotor warning horn sounded. He said that in an attempt to regain rotor RPM and arrest the decent, he rolled the throttle to the high position, increased collective pitch, and lowered the nose to gain airspeed. He said that the rotor RPM continued to decay, the helicopter impacted uneven terrain, and rolled over. The pilot stated: 'I just got into a downdraft on takeoff.' He added that there were no preaccident mechanical anomalies with the helicopter. The helicopter sustained substantial damage to the rotor system, and fuselage.