MLG ON DSCNT HAS TCASII RA; RESPONDS.

Narrative

ON VECTORS FOR APCH; WE WERE ASSIGNED 6000 FT MSL. APCHING LEVEL OFF; APCH CLRED US TO CONTINUE TO 5000 FT. AFTER ACKNOWLEDGING THE 5000 FT CLRNC; APCH INSTRUCTED US TO DSND TO 4000 FT WITHIN 4 NM. THE SPD BRAKES WERE PULLED; AND THE DSCNT RATE INCREASED BY 1000-1200 FPM. WE RECEIVED A TCASII TA THEN RA FOR TFC THAT WE WERE BEING DSNDED UNDER. AS WE WERE ALREADY IN THE 'EXPEDITED' DSCNT; THE RA WAS ACADEMIC EXCEPT FOR THE FACT THAT IT ILLUSTRATED A POTENTIAL CONFLICT. 2 FACTORS COME TO MIND AS THE FO AND I LATER REVIEWED WHAT HAD TRANSPIRED. FIRST; ALTHOUGH THE CLRNC TO 4000 FT WAS GIVEN WITH AN UNREALISTIC RESTRICTION (WITHIN 4 NM) WE DID NOT ARGUE OR COMPLAIN TO APCH; WE SIMPLY TRIED TO COMPLY NOT KNOWING WHAT AFFECT NON COMPLIANCE MIGHT HAVE. SECONDLY; WE REALLY HAD NO RELIABLE MEANS TO PRECISELY MARK OFF; 4 NM AS WE WERE NOT HDG DIRECTLY TO THE VOR;BUT 'ARCING' WHILE ON THE VECTOR FOR APCH. APCH HAD NOT ASKED IF WE COULD MAKE THE RESTRICTION PRIOR TO US ACCEPTING IT; HE PROBABLY DIDN'T HAVE TIME. I ULTIMATELY HAVE THE FINAL SAY IN ACCEPTING OR REJECTING A CLRNC; BUT WITHOUT KNOWING IF THE DELAY IN TRYING TO CLARIFY THE CLRNC WOULD HAVE AGGRAVATED THE SIT; I FELT (BEFORE AND AFTER) THAT ALL I COULD DO IS TRY TO COMPLY AS CLOSELY AS POSSIBLE. I'M NOT SURE OF THE CTLR'S SEPARATION CRITERIA; BUT WITH THE RA ISSUED BY TCASII; I'M SURE WE INFRINGED ON IT. AS BEST AS I COULD DETERMINE WE WERE 'WELL CLR' AT ALL TIMES; BUT IT WASN'T PRETTY.