PLT OF SMA IN TFC PATTERN AT UNCTLED ARPT TOOK EVASIVE ACTION TO AVOID ANOTHER SMA MAKING A TOUCH AND GO FROM STRAIGHT IN APCH.

Narrative

I TOOK OFF FROM RWY 20 INTENDING A FULL STOP AFTER 1 CIRCUIT OF THE TFC PATTERN. THERE WAS 1 OTHER PLANE IN THE PATTERN AHEAD OF ME. BY THE TIME I WAS ABEAM THE ARR END OF RWY 20; THAT ACFT HAD COMPLETED A TOUCH AND GO AND I HEARD ANOTHER ANNOUNCE INBOUND ON THE LOC 20 APCH. I ASKED THAT PLT WHERE HE WAS AND HE REPLIED HE WAS AT 'TALAC' (FINAL APCH FIX; 4/5 DME FROM THRESHOLD); AND THAT HE 'HAD ME IN SIGHT.' NOT SEEING ANYONE ON FINAL AND ASSUMING THE PLANE I SPOKE WITH WAS STILL 3-4 MI OUT; I TURNED A TIGHT L BASE. WHILE TURNING; I HEARD CALLS SUGGESTING ANOTHER PLANE ON THE LOC AND FEARING HE MIGHT BE CLOSER THAN THE ORIGINAL ACFT; I ROLLED OUT OF THE TURN TO LOOK BACK UP FINAL. AT THIS POINT A HIGH WING PLANE PASSED APPROX 500-1000 FT IN FRONT OF ME ON FINAL APCH. THE OTHER PLANE COMPLETED A TOUCH AND GO LNDG AND DEPARTED. SEVERAL ATTEMPTS TO CONTACT HIM ON CTAF WERE UNSUCCESSFUL. I DO NOT KNOW IF THE PLANE I ENCOUNTERED WAS THE ONE I SPOKE WITH OR ANOTHER ONE. PROBLEMS SUCH AS THIS ARE NOT UNCOMMON AT MGY WHEN ACFT EXECUTING THE LOC APCH MIX WITH VFR TFC IN THE PATTERN. EXTREME VIGILANCE IS REQUIRED AT ALL TIMES IN THE PATTERN.