NMAC AS SMT CANCELS IFR AND SMA IN SAME AIRSPACE.

Narrative

PROB AROSE WHEN CANCELLING IFR AND PROCEEDING VFR TO ORANGE COUNTY ARPT. AFTER BEING GIVEN VECTORS IT WAS DETERMINED THAT A VFR ARR AT SNA ARPT WOULD ELIMINATE THE NEED FOR AN INST APCH. COAST APCH NOTIFIED ME THAT CANCELLATION WAS RECEIVED AND TO PROCEED TO SNA ARPT VIA THE HUNTINGTON BEACH PIER ARR PROC VFR. WITHIN 10 SECONDS AFTER CANCELLING IFR (IN VFR CONDITIONS); AN SMA Y APPEARED IN THE WINDSCREEN WHICH WAS NBOUND AT MY ALT. BOTH ACFT TOOK EVASIVE ACTION. UPON ASKING COAST APCH (DISGRUNTEDLY) ABOUT THE POS OF THE SMA Y PRIOR TO CANCELLING IFR; THE CTLR SAID 'I LEFT MY POS ON THE SCREEN TO CALL SNA TWR TO NOTIFY THEM OF YOUR ARR. (I WAS MAINTAINING THE SAME XPONDER CODE AS ORIGINALLY ASSIGNED VIA MY IFR FLT PLAN) AND WHEN I LOOKED BACK AT MY RADAR SCREEN; BOTH ACFT WERE CONVERGING.' HE SAID; 'BY THAT TIME; IT WAS TOO LATE.' IN THE MEANTIME SNA ARPT HAD JUST GONE IFR; AND I INEVITABLY HAD TO FLY THE ILS APCH ANYWAY. THIS IS WHERE I BELIEVE THE PROB OCCURRED. THE ARPT WAS VFR AND JUST TURNING IFR; AND THE CTLR WAS DISCUSSING THIS WITH THE TWR (PERTAINING PROBABLY TO ANY INBOUND VFR TFC). THE CTLR SHOULD HAVE REALIZED THAT MY ACFT TYPE HAS THE ABILITY TO DSND AT AN AGGRESSIVE RATE AND THE RATE OF CLOSURE OF THE 2 AIRPLANES COULD HAVE CREATED A PROB. COAST APCH APOLOGIZED FOR THE LACK OF ATTN AND CONTINUED TO EXPLAIN THE SIT AT THE ARPT WHICH REQUIRED ME TO GO IFR AGAIN AND CLB BACK UP TO 4000 FT MSL FOR VECTORS TO THE APCH IN IMC CONDITIONS. UPON LNDG AT SNA ARPT (AND FLYING THE APCH IN WX WHICH DID DETERIORATE TO THE MINIMUMS IN RAIN); I WAS GIVEN A NOTE FROM THE CTL TWR TO CALL COAST TRACON; WHICH I DID. I SPOKE WITH THE SUPVR AT THE TIME AND HE SPECIFICALLY SAID THAT 'COAST HAD REALLY DROPPED THE BALL ON THAT ONE.' HE MENTIONED THAT THE SMA Y WAS ALSO TALKING TO COAST APCH; WHICH I FELT HARD TO BELIEVE. THE PROB FOR ME (IN VFR CONDITIONS) WAS THAT THE SMA Y WAS BELOW AND TO MY R WHICH WAS R IN MY 'BLIND SPOT.' I ACTUALLY BELIEVE THAT THE SMA Y SAW ME; BEFORE I SAW HIM. HE WAS ALREADY IN A SEVERE R HAND TURN TO AVOID ME AS I PULLED UP AND AWAY TO THE L. I REALIZE THE RULE OF 'SEE AND BE SEEN' IN VFR; BUT WHEN IN TRANSITION FROM IFR TO VFR; IT WOULD BE NICE TO KNOW ABOUT OTHER TFC IN THE VICINITY; INSTEAD OF JUST WRITING IT OFF TO 'VFR CONDITIONS.' NOTE: ALTHOUGH THERE WAS MUCH WX IN THE AREA; BOTH ACFT WERE CLRLY VFR. THE PROB OCCURS AGAIN THAT WHERE THE VFR WX IS LOCATED ON A MOSTLY IFR DAY; THAT'S WHERE ALL THE VFR TFC WILL BE.