NMAC ON LAX VISUAL APCH.

Narrative

WE WERE FLYING THE ARR INTO THE LOS ANGELES AREA AT 7000 FT. I HEARD A XMISSION BY APCH CTL POINTING OUT A '727 AT 'X' O'CLOCK TO ANOTHER ACFT. THAT ACFT RESPONDED WITH 'TFC IN SIGHT.' IT WAS THEN CLRED TO DSND. WE RECEIVED A TCASII TA ON A NEARBY ACFT. THIS WAS FOLLOWED BY A TFC RESOLUTION TO 'DSND! DSND!' THE CAPT IMMEDIATELY STARTED A DSCNT. THE AIRWAVES WERE FILLED WITH NON-STOP INSTRUCTIONS AND REPLIES; BUT I MANAGED TO INTERJECT; 'APCH; X DSNDING DUE TO TCASII.' APCH CTL REPLIED WITH SOMETHING LIKE; 'I DON'T RECOMMEND DSNDING: WE DON'T HAVE CTL OVER THAT AIR SPACE. THE OTHER ACFT HAS YOU IN SIGHT.' I EXAMINED OUR SCOPE AND ADVISED THE CAPT THAT THE OTHER ACFT WAS RIGHT ON TOP OF US. THE CAPT STARTED A R TURN IN ADDITION TO OUR DSCNT. WE WERE NOW AT ABOUT 6000 FT AND STILL DSNDING. AT SOME POINT I VAGUELY RECALL HEARING; 'WE LOST SIGHT OF THE ACFT.' I TOLD THE CAPT THAT THE OTHER ACFT WAS 300 FT AND DSNDING JUST TO OUR L (ACCORDING TO OUR TCASII SCOPE). I LOOKED OUT HIS WINDOW AND SPOTTED A JETSTREAM BA3100 SLIGHTLY ABOVE AND ABOUT 200-300 FT IN OUR 9 O'CLOCK POS. WE HAD ALREADY DSNDED FROM 7000 FT TO ABOUT 5800 FT; AND TURNED R FROM THE 068 RADIAL TO ABOUT 090 DEGS. THE RA HAD CONTINUED TO SOUND 'DSND! DSND!' DURING THE ENTIRE SIT. NATURALLY; IT HAD BEEN VERY TENSE IN THE COCKPIT; AND I MAY HAVE MISSED A POSSIBLE; ROUTINE-TONED. 'X TURN R TO 120.' I REPLIED WITH 'ROGER; TURNING TO 120 AT 6000 FT.' THE REST OF THE VECTORED APCH AND LNDG WERE UNEVENTFUL. 1) WE AVOIDED AN ALMOST CERTAIN MID-AIR COLLISION BECAUSE OF OUR TCASII INSTRUCTIONS; OUR PROMPT ACTION IN FOLLOWING THEM; AND OUR ADDING A TURN TO THE 'DSND!' RA. 2) ALTHOUGH APCH CTL APPARENTLY GAVE US A TURN TO 120 AFTER WE HAD DONE CONSIDERABLE MANEUVERING; IT WAS FAR TOO LATE TO HAVE AVOIDED THE CONFLICT! I CERTAINLY WOULD LIKE TO HAVE HEARD THE FIRST 'TURN TO 120' CALL: HOWEVER; I THINK IT WAS A BIT TOO LATE TO DO MUCH GOOD. WHEN THE OTHER ACFT SAID HE HAD THE TFC IN SIGHT; WAS THAT TFC US? DID HE EVER SEE US? DID HE HAVE A TCASII? IF HE DID; WAS IT GIVING HIM A TA AND SUBSEQUENTLY A RA? WHY DID APCH CTL INTENTIONALLY VECTOR 2 ACFT SO CLOSE TOGETHER; EVEN IF 1 SUPPOSEDLY SAW THE OTHER? WE WERE FLYING A STAR; NOT A FINAL APCH TO PARALLEL RWYS.) WHY DID APCH CTL TRY TO DISCOURAGE US FROM DSNDING TO AVOID A MID-AIR COLLISION? BUT THE JETSTREAM AND OUR B-727 TARGETS MUST HAVE BEEN PRETTY CLOSE TOGETHER ON HIS RADAR SCREEN! THE CTLR DID GIVE US INSTRUCTIONS TO TURN; BUT ONLY WELL AFTER THE FACT.