ACR ON DSCNT HAS NMAC WITH SMA.

Narrative

OUR ACFT ON V-39 TOLD TO DSND FROM 4000 FT TO 3000 FT MSL. WE BROKE OUT OF THE CLOUDS AT ABOUT 3800 FT MSL. APCH TOLD US 'NUMEROUS VFR AHEAD.' NO ALTS MENTIONED. AS SPARTA ARPT IS THERE; THIS IS A COMMON CALL. WE IMMEDIATELY SAW 2 ACFT BELOW US. THEN A THIRD WAS SEEN; DIRECTLY AHEAD AT ABOUT 3000 FT MSL. WE WERE DOWN TO ABOUT 3100 FT AT THIS TIME; SO I CALLED TO ATC THAT WE WERE CLBING BACK TO 3500 FT MSL TO AVOID TFC. THIS CALL WAS MADE SEVERAL TIMES; WITH NO RESPONSE (I WAS AWARE OF THE POSSIBILITY OF OTHER ACFT IN THE CLOUDS AT 4000 FT). THE OTHER ACFT; AN SMA Y OR POSSIBLY AN SMA X WAS MOVING VERY SLOWLY; WITH FLAPS EXTENDED; AND CLBING; SO I WAS RELUCTANT TO TURN BEHIND THE ACFT (INSTEAD OF CLBING) BECAUSE IT WAS OBVIOUSLY MANEUVERING; AND I COULD SEE THAT I COULD OUTCLB IT; BUT DID NOT WANT TO TRY TO OUT TURN IT. JUST BEFORE WE CROSSED OVER THE TOP; I DID DIVERT TO THE R A BIT. AFTER WE RETURNED TO 3000 FT; ATC FINALLY ACKNOWLEDGED THAT WE HAD HAD A PROBLEM. I TOLD THEM I'D BE FILING A RPT; AND IT SEEMED TO UPSET HIM; AT FIRST; BUT THEN I WAS GIVEN THE TELEPHONE NUMBER. WHY IN GOD'S NAME TRANSPORT CATEGORY ACFT ARE VECTORED AROUND TCA; AT 3000 FT; IS BEYOND MY CAPACITY TO UNDERSTAND. THERE WILL BE A COLLISION THERE UNLESS MEASURES ARE TAKEN TO CHANGE THE ALTS.