Event Summary
While maneuvering at an altitude of 35 to 40 feet above tree level, the pilot felt a shudder and low-frequency shaking of the rotor disk. The rotor RPM and engine RPM decreased, and the aircraft entered a shallow descent.
Pilot Actions
The pilot applied forward cyclic, reduced collective, and increased throttle. With insufficient altitude to recover from the descent, the pilot maneuvered the aircraft away from tall trees and settled it into an area of small trees.
Investigation Findings
Post-accident examination revealed no mechanical failure or malfunction. The accident site altitude was 2000 feet MSL with a density altitude of approximately 4500 feet MSL.