COS DEP CTLR FELT A B727 PLT'S RESPONSE TO A TCASII RA WAS UNNECESSARY BECAUSE HE HAD ENSURED SEPARATION AND ISSUED TFC TO BOTH ACFT.

Narrative

ACR Y (B727) LEVEL AT 11000 FT; HDG 350 DEGS. ACR Y (MD80) DEPARTED COS; HDG ASSIGNED 120 DEGS; ALT ASSIGNED 10000 FT. I ISSUED TFC TO BOTH ACFT. ACR X RPTED ACR Y IN SIGHT. ACR Y WAS LEVEL AT 10000 FT. AS TARGETS MERGED; ACR X CLBED TO 11500 FT AND ADVISED ATC THEY WERE RESPONDING TO AN RA. I QUESTIONED ACR X IF THEY HAD THE TFC IN SIGHT. THE PLT RESPONDED; 'YES WE DO; BUT HAVE AN RA AND HAVE TO CLB.' ACR Y THEN INFORMED ME THAT THEY RECEIVED A TA. THE PLT'S COMMENT WAS 'JUST AN FYI.' QUESTION: WHY WOULD THE B727 GET AN RA AND THE OTHER ONLY A TA?' I FEEL THAT SINCE ACR X RPTED THE TFC IN SIGHT AND WAS TOLD THAT THE MD80 WAS GOING TO LEVEL AT 10000 FT; THE RESPONSE TO THE RA WAS UNNECESSARY. AN RA IN THIS CASE; HAD THERE BEEN ANOTHER ACFT AT 12000 FT; WOULD HAVE CAUSED A SAFETY ISSUE. I FEEL THAT TCASII IS A GOOD TOOL BUT SITS LIKE THESE CAUSE ME TO BUILD IN MORE THAN STANDARD IFR SEPARATION. SINCE THE CTLR ENSURED SEPARATION; INFORMED BOTH CREWS; AND THE ACR X CREW HAD ACR Y IN SIGHT; THE TCASII RA CLB IS NOT JUSTIFIED.