Robinson Helicopter R22 BETA N80140 accident near Rockport, Washington

Probable cause

The pilot's failure to maintain sufficient rotor rpm during a precautionary landing, which resulted in a hard landing.

NTSB analysis

The pilot reported that while maneuvering, the helicopter’s clutch caution light illuminated. The pilot initiated a precautionary descent and began to slow the helicopter in an effort to locate a clearing in the trees. The clutch caution light was still on after 10 to 12 seconds, so the pilot instructed his passenger to pull the circuit breaker. The pilot spotted a clearing, and shortly thereafter the low rotor rpm warning light illuminated and the horn sounded. The pilot lowered the collective and headed for a landing spot. About 20 to 30 feet above ground level, the pilot flared the helicopter and used the remaining collective control input the last 3 to 5 feet. The helicopter subsequently landed hard in high brush surrounded by tall trees.

During the postaccident examination, bench testing of the clutch actuator revealed that the actuator operated normally and within specified limitations. Further examination of the actuator motor found no anomalies that would have precluded normal operation. The reason for the illumination of the clutch light could not be determined.

Text from the NTSB. Open the NTSB docket for WPR13LA003 for the full record.