CAPT OF A B737-300 INSTRUCTED THE FO TO SLOW DSCNT FOR A TCASII TARGET THAT WAS INDICATED IN CLOSE PROX TO THEIR FLT PATH ON A STAR ARR. THE TARGET WAS SUBSEQUENTLY SIGHTED; AND A TA ISSUED; OF A B727 ON THE SAME ARR.

Narrative

WE WERE DSNDING ON THE PANOCHE 2 ARR FROM SAN TO OAK. CTR HANDED US OFF TO APCH CTL (134.5). BAY APCH GAVE US A DSCNT TO 7000 FT. I NOTICED ON THE TCASII THAT WE HAD A TARGET APCHING US FROM 1 O'CLOCK THAT APPEARED TO BE AT 7000 FT. I TOLD THE FO (PF) TO SHALLOW HIS RATE OF DSCNT. WE VISUALLY ACQUIRED THE ACR Y B727 BELLY UP TO US IN A TURN. WE STOPPED THE DSCNT ABOUT 500 FT ABOVE HIM TO ENSURE HE COULD SLIDE UNDER US IF NECESSARY. APCH CTL THEN CALLED OUT THE TFC; WE ACKNOWLEDGED TFC IN SIGHT; AND WERE TOLD TO MAINTAIN VISUAL SEPARATION. APCH THEN DSNDED THE ACR Y TO 6000 FT. APCH THEN PROCEEDED TO GIVE US PARALLELING VECTORS TO OAK RWY 29 THAT NEVER PRODUCED MUCH LATERAL SEPARATION. WE BEGAN TO SLOW. APCH CLRED US VISUAL APCH BEHIND THE ACR Y B727. WE IMMEDIATELY PUT THE GEAR AND FULL FLAPS DOWN AS WE WERE ABOUT 2000 FT HIGHER THAN NORMAL AND ALMOST ON TOP OF THE ACR Y LATERALLY. THIS CREATED A GND SPD DIFFERENCE AND LATERAL SEPARATION. AT THIS POINT A NEW VOICE GAVE US A 90 DEG TURN OFF COURSE FOR SEPARATION AND THEN TURNED US BACK FOR THE APCH. WE DID OUR BEST TO COMPLY WITH ALL THE CTLR'S INSTRUCTIONS. I USUALLY KEEP THE TCASII ON 10 MI RANGE IN THE TERMINAL AREA ON THE IVSI AND 20 MI RANGE ON THE RADAR. THIS ALLOWED US TO SPOT THE CONFLICT BEFORE A TA OR RA WAS PRODUCED AND TO ADJUST OUR FLT PATH ACCORDINGLY. A TA DID SHOW UP AT THE B727 CLOSEST POINT OF APCH. BY THIS TIME WE WERE EASILY MAINTAINING VISUAL SEPARATION. I LOVE TCASII.