SMA ON BASE FOR LNDG HAS NMAC WITH SMA AT LOW ALT. EVASIVE ACTION.

Narrative

I REQUESTED IFR TERMINATION; AND A VFR DIVERT TO POINT MUGU. I WAS INSTRUCTED TO SQUAWK 1200; AND TO MAINTAIN VFR. I CONTACTED CAMARILLO TWR (128.2) AT THE BASE OF THE CONEJO GRADE. I ASKED FOR AND RECEIVED PERMISSION TO 'XMIT THE CMA ATA AT OR ABOVE 2000 FT.' I THEN PROCEEDED TOWARDS PT. MUGU. APPROX 2 MI NE OF ROUND MOUNTAIN; CMA GAVE ME A FREQ CHANGE TO MUGU TWR. I CONTACTED MUGU TWR ON 124.89. I ADVISED THEM THAT I 'WAS JUST OUTSIDE ROUND MOUNTAIN; 1.3 DSNDING TO 700 FT; FULL STOP; NEGATIVE ATIS.' MUGU INSTRUCTED ME TO RPT 1 MI R BASE TO RWY 27. WHILE IN MY DSCNT; I SAW A WHITE AND BLUE SMA GOING L TO R; APPROX 50 FT LOWER THAN I; APPROX 300 FT IN FRONT OF ME. I MADE A SHARP L BREAK TO MISS HIM; AND RPTED THE INCIDENT TO MUGU TWR. IT APPEARED THAT THIS SMA FLEW DOWN THE CANYONS BEHIND THE VTU VORTAC; POSSIBLY VIOLATING PT. MUGU'S ATA. IT WAS NOT ISSUED AS TFC. SUPPLEMENTAL INFO FROM ACN 202932: FAILURE OF OTHER ACFT TO FOLLOW PRESCRIBED PATTERN ENTRY TECHNIQUE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CALL BACK MADE DUE TO BREVITY OF RPT. DETERMINED IT IS A MATCH OF 202789. RPTR STATES CONFLICT OCCURRED AT 4 MI ON 030 LINE OF POS FROM NTD. RPTR ACFT HAD BEEN CLRED FOR THIS ENTRY. NTD HAS 3 ENTRY FOR TFC PATTERN ENTRY AT 700 FT. RPTR ACFT COM WITH APCH; CMA TWR; THEN NTD TWR. INTRUDER ACFT NOT IN CONTACT WITH ANYONE. APPARENTLY TRYING TO AVOID CONTACT WITH NTD BUT AT CONFLICT POINT INSIDE CMA ATA AS WELL. NOT PROPER ENTRY FOR CMA TFC PATTERN. TOO CLOSE FOR COMFORT.