NMAC. UNCTLED ARPT; 2 OTHER ACFT RPTED IN R TFC PATTERN; RPTR ENTERED PATTERN AND SAW HELI; THOUGHT HELI WOULD LAND SOMEWHERE OTHER THAN RWY; HAD TO LAST MIN GAR TO EVADE THE HELI.

Narrative

APCHING SANDERSON FIELD I MONITORED 122.8 AND HEARD 2 ACFT IN R HAND PATTERN SO I ENTERED A 45 DEG TO R DOWNWIND AND RPTED. I ALSO CALLED ON A 2 MI FINAL TO RWY 23. ABOUT 3/4 MI OUT A HELI SEEN ENTERING SHORT FINAL FROM A R BASE (DIFFICULT TO SEE BECAUSE OF THE LOW SUN). I ASSUMED HE WOULD GO SOMEPLACE OTHER THAN THE RWY AND WOULD NOT BE A CONFLICT; BUT HE GOT TO THE END OF THE RWY AND STOPPED. I DON'T KNOW IF HE LANDED OR WAS HOVERING LOW. MY CLOSURE RATE WAS SURPRISING AND I REACTED LATE. I ADDED FULL PWR PULLED UP AND BANKED R. I DON'T KNOW HOW CLOSE I CAME; BUT MUCH TOO CLOSE FOR COMFORT. WE COMMUNICATED AS HELI AND CARDINAL AND HE ASKED IF I WOULD BE LNDG AND I SAID YES THINKING WE COULD TALK ABOUT IT. WHEN I LANDED AND TURNED OFF THE RWY HE WAS NOWHERE TO BE FOUND. APCHING THE ARPT ON 122.8 I HEARD 2 ACFT IN R TFC; TURNS OUT THEY WERE BOTH HELIS. THE PATTERN SHOULD BE L. I RELIED ON WHAT I HEARD. I GUESS HELIS USE R TFC THERE I DON'T KNOW. I SHOULDN'T HAVE ASSUMED THE HELI ENTERING FINAL IN FRONT OF ME WOULD LAND SOMEWHERE ELSE ON THE FIELD. I WAS THE ONE IN A FINAL POS TO PREVENT AN ACCIDENT AND I SHOULDN'T HAVE DELAYED.