Incident Overview
According to the pilot's report, the helicopter was conducting a mission to drop off crew members and collect secured bundles of trash from a remote landing zone. The pilot had performed several landings at this location throughout the day without issue. Following an uneventful touchdown, the aircraft experienced a sudden and violent shaking.
Pilot Actions
The pilot maintained control of the helicopter as the shaking continued, and successfully shut down the engine after the vibrations ceased. No further operational abnormalities were noted after the shutdown.
Witness Account
A witness on the ground reported observing a tarp from a nearby trash bundle being lifted into the air and striking the main rotor blades. As a result of the impact, one of the main rotor blades detached from the helicopter and suffered substantial damage.
Aircraft Examination
Subsequent inspection of the airframe and engine revealed no mechanical failures or malfunctions that would have prevented normal operations. The incident was attributed to the foreign object debris (the tarp) coming into contact with the rotor system.
Aftermath
The helicopter was left with significant damage to the main rotor assembly due to the blade loss. No other injuries or damage were reported beyond the rotor system.