TCASII ALERTS RPTR TO TFC THAT HE SEES AND AVOIDS.

Narrative

1) I WAS CONDUCTING RTE TRAINING AS INSTRUCTOR PLT PERFORMING PNF DUTIES. ATC (ZOA) REQUESTED 'MAX FORWARD SPD.' I RESPONDED WITH .86/320 KTS; WHICH THE CTLR SAID WAS SATISFACTORY -- YOU'RE #1 ON THE ARR. 2: ZLA REQUESTED A LEVEL OFF AT FL240 (DSNDING FROM FL350) WHICH PUT US HIGH ON THE PROFILE -- THEN A SHORT TIME LATER (APPROX 2-3 MIN) RECEIVED CLRNC TO CROSS SYMON AT 12000 MSL PER STAR. 3) SOCAL APCH REQUESTED EARLY SPD REDUCTION TO 280 KTS PRIOR TO SYMON. I REQUESTED TO CROSS SYMON ABOVE 12000 FT -- SOCAL REPLIED UNABLE. THE INTERMEDIATE LEVEL OFF AT FL240 AND SUBSEQUENT EARLY SPD REDUCTION REQUIRED SPDBRAKES AND I WAS 'HEADS DOWN' ENSURING THAT WE CROSSED SYMON AT 12000 FT WHICH WAS TIGHT. 4) JUST AS WE RECEIVED OUR TCASII RA (I DISCONNECTED AUTOPLT AND FOLLOWED RA 'CLB COMMAND) SOCAL ADVISED MAINTAIN ALT -- TFC AT -- -- JUST POPPED UP. WE SAW THE TFC IN A L TURN MANEUVERING AWAY FROM US. WE THEN CONTINUED DIRECT TO SMO VOR COMPLETING THE ARR. CHAIN OF EVENTS: 1) VISIBILITY WAS EXCELLENT (90 MI RPTED AT LAX) HOWEVER DUE TO LACK OF COORD BTWN ZOA AND ZLA; AND SOCAL APCH RESULTING IN OUR CONCERN MAKING OUR XING RESTRICTION WE WERE BOTH 'HEAD DOWN' -- PERHAPS I WOULD HAVE SEEN THE OTHER ACFT SOONER IF I HAD BEEN LOOKING OUTSIDE -- WE IMMEDIATELY SPOTTED THE OTHER ACFT AFTER RECEIVING THE RA AND ATC TFC INSTRUCTION TO 'MAINTAIN ALT.' 2) THE CONFLICT OCCURRED JUST PRIOR TO DSNDING INTO THE CLASS B AREA -- UPPER LIMIT 12500 FT -- CONFLICT AT 13500 FT. 'SEE AND BE SEEN' IS NOT SATISFACTORY IN MAINTAINING SEPARATION DUE TO FLT DECK TASKS AND SPDS INVOLVED; ALTHOUGH THE LEVEL OF SAFETY IS INCREASED WHEN A PLT CAN LOOK OUT. THE SOLUTION IS FOR THE UPPER LIMIT/FLOOR TO PROTECT THE ACFT ON SID/STAR -- E.G.; CORRIDORS TO AND FROM CLASS A AIRSPACE.