TCASII TA RA SENSES A POTENTIAL CONFLICT WITH CLBING XING TFC IN VFR CLB THROUGH OCCUPIED ALT. RPTR CITES ARTCC RADAR CTLR TECHNIQUE ATC AS CAUSAL. TRULY A SEE AND AVOID CONCEPT THAT WAS SCHEDULED BY ATC.

Narrative

CLRED DIRECT SOLBERG VOR AT 12000 FT. IN CRUISE; LEVEL AT 12000 FT; APPROX 20 MI NE OF VOR; SAW 737 TFC 10 O'CLOCK; LOW. CTR (120.75) ADVISED OF TFC. WE REPLIED IN SIGHT. CTR SAID HE WAS AT 11000 FT AND ASKED 737 IF HE HAD US IN SIGHT. HE REPLIED AFFIRMATIVE. CTR TOLD US TO MAINTAIN VISUAL SEPARATION AND TOLD OTHER ACR 737 TO CLB. I COULD SEE THAT HE WOULD PASS BELOW; ON PRESENT FLT PATHS; SO I TURNED L TO PASS BEHIND HIM IN ORDER TO MAINTAIN VISUAL CONTACT. IN TURN; GOT A TCASII RA 'CLB-CLB' INDICATING WE SHOULD CLB AT 2500 FPM. I DID CLB AND AT 12400 FT THE 'CLR OF CONFLICT' SOUNDED AND I DSNDED BACK TO 12000 FT. I ASKED CTLR WHY WE WERE THE ONE GIVEN THE RESPONSIBILITY TO MAINTAIN SEPARATION WHILE THE OTHER ACFT WAS THE ONE CHANGING ALT. ALSO ADVISED OF TCASII RA. HE SMUGLY REPLIED; 'IT'S LEGAL.' HAD ATC WAITED 1 MIN; OUR PATHS WOULD HAVE CROSSED AND NO CONFLICT COULD HAVE BEEN POSSIBLE. THIS SAME SIT HAS OCCURRED TO ME; IN APPROX THE SAME LOCATION; ABOUT 6 TIMES BEFORE. WHAT IS THE BIG RUSH TO CLB THESE JETS WHEN A FEW MINS OR LESS WILL AVOID TFC CONFLICTS? ACR Y SAID HE STARTED TO CLB THEN STOPPED; UNTIL CLR OF US. IN IMC THIS WOULD NOT HAVE HAPPENED. IN THE FUTURE; I WILL REFUSE TO MAINTAIN VISUAL SEPARATION ('UNABLE') FOR ATC.