C182 CIRCLES ON FINAL TO AVOID HELI ON APCH TO SAME RWY.

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I WAS CLRED TO LAND #1 AT DTO ON RWY 17. I WAS ON A R BASE AT ABOUT 2 MI FROM THE THRESHOLD. THE TWR INFORMED ME I HAD TFC; WHICH WAS A HELI; ON A LONGER STRAIGHT IN FINAL; AND TO ADVISE WHEN I HAD THIS TFC IN SIGHT. THE HELI WAS SHOOTING AN ILS TO RWY 17. I SPOTTED THE TFC SLIGHTLY OFF MY NOSE TO THE L AT ABOUT 500 FT HORIZ DISTANCE AND ONLY 100-200 FT OF VERT SEPARATION. I IMMEDIATELY MADE A L HAND; SLIGHTLY CLBING; 360 DEG TURN FOR SPACING AND ADVISED TWR AS SOON AS PRACTICAL AND AS SOON AS THE RADIO WAS CLR FOR XMISSION. UPON NOTIFICATION TO THE TWR; I WAS INFORMED TO TURN DIRECTLY TOWARD THE RWY AND CONTINUE FOR LNDG AND THE HELI WAS GOING TO SIDESTEP THE RWY FOR PRACTICE LNDGS. I LANDED WITHOUT FURTHER INCIDENT AND TAXIED IN TO THE RAMP. THE TWR KINDLY ADVISED ME THAT HE WAS GOING TO HAVE THE HELI SIDESTEP THE RWY TO ALLOW FOR SPACING. I; UPON SEEING THE HELI ON FINAL; WAS NOT COMFORTABLE WITH THIS AMOUNT OF SPACING AND TOOK IMMEDIATE AND APPROPRIATE ACTION TO ALLOW FOR A LARGER MARGIN OF SAFETY.