What happened
On October 3, 2012, at approximately 1340 Pacific daylight time, a Robinson R22 Beta helicopter, registration N80140, performed a hard landing approximately 32 nautical miles north of Rockport, Washington, within the North Cascades National Park. The flight, which originated from Skagit Regional Airport in Burlington, Washington, was operating under visual meteorological conditions.
While maneuvering, the pilot observed the clutch caution light illuminate and remain steady. In an attempt to find a clearing among the trees, the pilot began a descent and slowed the aircraft. After the light remained illuminated for 10 to 12 seconds, the pilot instructed the passenger to pull the circuit breaker. Shortly after spotting a clearing, the low rotor RPM warning light activated and the warning horn sounded. The pilot lowered the collective and proceeded toward a landing spot. The pilot flared the aircraft approximately 20 to 30 feet above the ground and used collective control for the final three to five feet, resulting in a hard landing in high brush surrounded by tall trees. The pilot and passenger were not injured.
The investigation
Video footage from a National Park Service representative showed the aircraft in the brush with a separated tailboom, damaged tail rotor blades, and a buckled fuselage. Subsequent examination of the wreckage revealed additional buckling in the fuselage, a damaged left skid assembly, and a bent rear cross-tube. The drive belts were found to be properly positioned and in unremarkable condition.
The clutch actuator was found in the extended position. During testing, the actuator motor produced an inconsistent noise and intermittent squealing during its range of travel. The actuator was later removed and examined by the Robinson Helicopter Company, where it was found to operate normally within limits. Examination of the actuator motor revealed a damaged wiring grommet and dust on the interior of the magnets and the rotor, but the brushes and commutator showed signs of normal operation. The bearing on the output shaft side felt slightly rough when rotated manually.