N666SL

The pilot stated that he completed the before takeoff checks and got the helicopter "light on the skids" before lifting off from the refueling pad. A slight yaw to the left became a rapid spin to the left that could not be corrected with right-pedal input. The pilot closed the throttle, lowered collective, and closed the mixture control to arrest the spin. On the fourth rotation, the tail struck a pole-mounted fire extinguisher, and the helicopter came to rest upright. The pilot reported that there were no mechanical deficiencies with the helicopter, and stated that his heavy coat and boots worn to combat the unseasonably cold weather may have interfered with the flight controls.