SIAI MARCHETTI AND CESSNA HAVE NMAC IN UNCTLED TFC PATTERN AT MGJ.

Narrative

I WAS APCHING MGJ (ORANGE COUNTY ARPT IN MONTGOMERY; NY) FROM THE S FOR LNDG. I WAS MONITORING THE UNICOM FREQ AND WAS AWARE OF A CESSNA (BIRDDOG) IN THE PATTERN (WHICH; FOR THAT ARPT IS A STANDARD L-HAND PATTERN) APPROX 3 MI FROM THE ARPT (WHICH IS UNCTLED). I ANNOUNCED THAT I WAS LNDG. ANOTHER CESSNA (C172 OR C182) RPTED THAT HE WAS ON A R DOWNWIND (NONSTANDARD). BECAUSE OF THIS; I DECIDED TO DO AN UPWIND ENTRY AT PATTERN ALT WITH A L TURN TO DOWNWIND. I ANNOUNCED MY INTENTIONS ON THE UNICOM AND DESCRIBED IN DETAIL ON THE RADIO WHAT I WAS ABOUT TO PERFORM. APPROX 1 MI FROM THE RWY THRESHOLD; I AGAIN CALLED UNICOM; INFORMED BOTH ACFT IN THE PATTERN THAT I HAD THE TFC IN SIGHT. THE CESSNA IN A R PATTERN WAS DSNDING IN A R BASE. I MAINTAINED VISUAL CONTACT AS I PROCEEDED UPWIND. THE CESSNA CAME WITHIN APPROX 300 FT; BOTH VERTICALLY AND HORIZONTALLY FROM MY ACFT AS HE TURNED FROM BASE TO FINAL. AT NO TIME DID HE OR I HAVE TO ALTER COURSE. THE CESSNA PLT ANNOUNCED ON THE UNICOM THAT HE FELT I ACTED IN A RECKLESS MANNER; WHICH I DID NOT. AFTER I LANDED; I WAS APCHED BY THE PLT OF THE BIRDDOG (THE ACFT ON L DOWNWIND); WHO APCHED ME WAVING A BADGE; SAYING THAT HE WAS FROM 'HOMELAND SECURITY.' HE SAID THAT IF THE CESSNA PLT WANTED TO 'PRESS CHARGES;' THAT HE WOULD 'APPEAR IN COURT.' I TRIED TO EXPLAIN TO HIM THAT BECAUSE OF PARALLAX AND HIS RELATIVE POS (OVER 1/4 MI); HIS PERCEPTION OF WHAT OCCURRED WASN'T WHAT HAPPENED IN REALITY. I MAINTAIN THAT I ACTED IN A PRUDENT MANNER; THAT NO FARS WERE BROKEN; AND THAT AT NO TIME WERE ANY OF THE INVOLVED ACFT IN JEOPARDY. IN RETROSPECT; HOWEVER; I COULD HAVE ABANDONED MY APCH.