NMAC BETWEEN DESCENDING ACR-MLG AND CRUISING GA-SMA.

Narrative

AS WE WERE IN OUR DSCNT; WE WERE TOLD TO EXPECT A XING ALT WHICH WAS REVISED TWICE AND WERE EVENTUALLY CLRED TO CROSS 5 MI E OF PALMDALE AT 12000' AND 10 MI W OF 8000'. THE AUTOPLT WAS ON AND PROGRAMMED ACCORDINGLY. AFTER THIS; THE CAPT TURNED THE RADIO COMS OVER TO ME WHILE HE ATTEMPTED TO GET THE ATIS INFO WHICH WE HAD BEEN UNABLE TO RECEIVE EARLIER DUE TO INTERFERENCE. WHILE HE WAS ON THE OTHER RADIO; WE RECEIVED A TFC ADVISORY AT 1 O'CLOCK; 3 MI. IT WAS HAZY AND AFTER LOOKING UNSUCCESSFULLY I RPTED THAT WE DIDN'T HAVE THE TFC IN SIGHT. ATC RESPONDED; 'ROGER.' ABOUT 30 SECS LATER (A GUESS) A LIGHT ACFT CAME INTO VIEW AT THE SAME ALT ALMOST DIRECTLY IN FRONT OF OUR FLT PATH. I PUSHED THE YOKE FORWARD WHICH DISCONNECTED THE AUTOPLT. WE PASSED BELOW AND SLIGHTLY LEFT OF THE SMA. I TOLD THE CAPT THAT I THOUGHT THE CTLR MUST HAVE MISUNDERSTOOD MY STATEMENT THAT THE ACFT TFC WASN'T IN SIGHT. HE CALLED EDW APCH ON THE GND IN BUR TO CLARIFY THE INCIDENT. SUPPLEMENTAL INFO FROM ACN 91405: WHILE RETURNING TO BUR ON 7/WED/88; I HEARD THE CTLR ANNOUNCE TFC AT '10500 LEVEL' TO AN MLG. A FEMALE VOICE RESPONDED; AND ALTHOUGH I DO NOT RECALL THE EXACT WORDING OF THE RESPONSE; IT DID SEEM TO ME THAT SHE HAD SIGHTED THE TFC; WHICH I ASSUMED WAS ME. A FEW SECS LATER THE FEMALE VOICE EXCLAIMED; 'OH SHIT;' WHICH SENT A CHILL THROUGH ME. WITHIN SECS AN MLG PASSED RIGHT UNDERNEATH MY LEFT WING WITHIN 100-200' AT THE MOST. I ANNOUNCED THIS FACT TO THE CTLR IMMEDIATELY. AFTER A FEW MORE SECS; I ANNOUNCED TO THE CTLR THAT I WOULD BE RPTING THE INCIDENT AS A NEAR MISS. A FEW SECS LATER A MALE MLG PLT ANNOUNCED TO THE CTLR THAT THEY DID NOT RPT THAT THEY HAD THE TFC IN SIGHT; BUT THAT THEY DID NOT HAVE IT. MOMENTS LATER THE CTLR ASKED ME TO TURN LEFT TO 120 DEGS. AFTER FLYING THIS HDG FOR A WHILE; I ASKED FOR PERMISSION TO TURN RIGHT TO PROCEED TO BUR. THE CTLR APPROVED MY REQUEST AND ASKED ME TO WATCH FOR TFC. WE LANDED AT BUR W/O FURTHER INCIDENT. IT WAS EVIDENT THAT THERE WAS A MISUNDERSTANDING OR MISCOM BTWN THE FEMALE PLT AND THE CTLR AS TO WHETHER THE MLG HAD THE TFC IN SIGHT. TO ENSURE THAT THIS SITUATION SHOULD NOT OCCUR AGAIN; TERMINOLOGY; 'NEGATIVE ON TFC;' SHOULD BE MANDATORY. ALSO; THE CTLR COULD HAVE VECTORED ME OFF TO ONE SIDE BEFORE THE INCIDENT OCCURRED INSTEAD OF AFTER THE FACT TO PROVIDE HORIZ SEP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR REQUESTED THAT THE TAPES BE SAVED SO HE COULD LISTEN TO THEM; BUT HAS NOT HAD OPPORTUNITY TO DO SO YET. COULD NOT UNDERSTAND WHY HE WAS VECTORED AFTER THE NMAC. HE THOUGHT THE MLG RPTED TFC IN SIGHT AND ASSUMES THE CTLR ALSO GOT THAT INTERP OF THE MLG ANSWER TO TFC AND THEREFORE NO VECTORS GIVEN. ALSO STATED WAS BEAUTIFUL CLEAR DAY BUT FELT MLG MAY NOT HAVE SPOTTED SMA SOONER AS THEY WERE LOOKING DOWN FROM ABOVE AND SMA MAY HAVE BLENDED IN WITH BACKGROUND.