NTSB Factual Report

The pilot stated that he was taking off from a dolly for a track and balance maintenance flight. He said that while hover taxiing the right door blew open. Shortly thereafter, he noticed that his clipboard was about to fall out of the helicopter. He quickly tried to transfer his left hand to the cyclic so that he could use his right hand to stop the clipboard from falling. He said that he put in too much aft cyclic and the tail guard struck the ground. Examination by a FAA inspector revealed that the tail boom was buckled. The pilot did not report any mechanical anomalies prior to the accident

NTSB Probable Cause

The pilot's improper preflight preparation and his failure to maintain control of the helicopter.