N519PA

The pilot reported that the purpose of the flight was to drop off crew members and pick up secured bundles of trash from a remote landing zone. He had landed at this landing zone several times throughout the day. After an uneventful landing, the helicopter started to shake abruptly. The pilot maintained control of the helicopter until the shaking stopped and he could shut down the engine. A witness reported that a tarp from a nearby trash bundle had flown up into the main rotor blades; subsequently, one of the main rotor blades departed the helicopter and sustained substantial damage. There were no mechanical failures or malfunctions with the airframe or engine that would have precluded normal operations.