A109 PILOT MAKING LOW PASS REPORTS CONFLICT WITH OPPOSITE DIRECTION GA ACFT ON TKOF ROLL.

Narrative

WHEN DEPARTING A PUBLIC RELATIONS EVENT THAT TURNED OUT TO ALSO BE A SMALL SCALE AIR SHOW; THE AIR SHOW COORDINATOR ASKED IF I COULD MAKE A PASS DOWN THE PARALLEL TXWY ON OUR WAY HOME. THE ACTIVE RWY WAS RWY XX WITH STRONG WINDS FROM THE S. THE FLT DOWN THE PARALLEL TXWY WOULD BE OPPOSITE THE FLOW OF TFC. I AGREED ASSUMING THAT THE CTLR WOULD STOP NORMAL DEPS WHILE I WAS MAKING THE RUN DOWN THE PARALLEL TXWY. I DEPARTED FROM THE PARALLEL TXWY; TO THE S AND WITH THE NORMAL TFC FLOW FOR A HELI AT AN UNCTLED ARPT; AND MADE ALL THE APPROPRIATE RADIO CALLS ON THE UNICOM FREQ. AFTER PROCEEDING APPROX 1 MI S OF THE ARPT; I REVERSED COURSE AND MADE THE APPROPRIATE ANNOUNCEMENT GIVING MY INTENTIONS TO FLY OVER THE PARALLEL TXWY. I WAS IN CONSTANT RADIO CONTACT WITH THE COORDINATOR THROUGHOUT THE MANEUVER AND DID NOT HEAR ANYONE PREPARING TO TAKE OFF FROM THE RWY. AS I WAS LINING UP FOR THE NBOUND FLT OVER THE PARALLEL TXWY; I NOTICED A SMALL SINGLE ENG AIRPLANE BEGIN HIS TKOF RUN. TO AVOID A POSSIBLE OPPOSITE DIRECTION CONFLICT; I TURNED AWAY FROM THE DEPARTING FIXED WING AND IT TURNED AWAY FROM OUR HELI. THOUGH THERE WAS NEVER A THREAT THAT WE WOULD COLLIDE; THIS DOES OFFER AN OPPORTUNITY TO REITERATE THE IMPORTANCE OF MAKING THE APPROPRIATE RADIO CALLS WHEN OPERATING AT AN UNCTLED ARPT. ALSO; IT'S IMPORTANT TO NEVER ASSUME ANYTHING IN REGARDS TO THE INTENTIONS OF ANOTHER ACFT THAT IS OPERATING IN CLOSE PROX TO YOUR OWN ACFT. WE ALL KNOW THAT 'ASSUME' CAN 'MAKE AN A#! OUT OF YOU AND ME.'