19980817021069A

Helicopter began to lose rotor RPM. Tried to auto rotate but was unsuccessful, and acft crashed while on approach. (.4) during an instructional solo cross-country flight, about 1 hour 25 minutes after takeoff, the helicopter's engine lost power. During the ensuing autorotational landing, the helicopter impacted trees. The pilot reported that after the second time the rotor RPM briefly decreased from the normal operating range, he elected to land the helicopter. The pilot further reported that the engine 'sounded' okay. During the descent for landing, at 1,000 feet MSL, the engine started losing power. A witness observed the helicopter at an estimated altitude of 1,500 feet. The engine was 'cutting in and out and the aircraft was yawing.' Examination of the accident site by FAA inspectors revealed no evidence of a fuel spill. A total of one cup of fuel was drained from both fuel tanks, and about one ounce of fuel was found in the gascolator. According to the helicopter manufacturer, the fuel consumption for this helicopter is 12-14 gallons per hour. The airline transport rated pilot undergoing instruction for a helicopter rating and his flight instructor visually checked t uel level prior to departure. The flight instructor estimated there was a total of 25 gallons of fuel on board. (-23) aircraft N1103R was enroute from gls to iws on a solo training flight. Mr. Jay knudsen was the only occupant on board the rotor RPM became erratic around the aap area. Mr. Knudsen initiated an autorotation, but rotor RPM was too low. The aircraft crashed along side of a road just north of approach end of runway 16 at aap. Upon arrival I discovered that there was only about one cup of fuel total in both tanks, and only a few dropt in the sump. The aircraft lost power and crashed due to fuel starvation. I recommend counseling and instruction on fuel planning with a qualified rotorcraft instructor pilot.