19990621007399A

Experimental rw exec 90 helicopter experienced engine failure at 300 feet AGL, and the pilot auto-rotated the acft to the ground, other circumstances are unknown. (.4)the non-certificated pilot preflighted the helicopter and after engine start, one of the magnetos was intermittent. Manipulation of the magneto switch corrected the problem; the flight then departed and flew about 5 miles away. While returning, the non-rotorcraft rated passenger began flying the helicopter and while descending over the airport about 300 feet, the engine quit. The passenger lowered full collective, maintained 60 mph, then when the helicopter was 20 feet AGL, he flared using a 45 degree flare angle. The tailboom contacted the ground first, followed by the main rotor blades contacting the tailboom. The helicopter then landed hard. The passenger stated after takeoff, the pilot performed 3 or 4 simulated loss of engine power with power recoveries and while performing another, the engine quit at 100-150 feet. He took the controls from the pilot and with the main rotor tachometer indicating 0, performed an autorotative landing but the helico pter landed hard. The engine was started postaccident and found no evidnece of preimpact failure of malfunction. The pilot stated that he found corrosion at the wiring connections at each ignition pack. Preflight examination of the ingnitions packs it required. (-23)see inspector statement.