APCH CTLR HAS ACFT VECTORED THROUGH LOC AND CONFLICTS WITH ACR ON PARALLEL RWY. POSSIBLE LTSS.

Narrative

OPERATING AS FLT X NON PAX REPOS FLT TO ATL FROM CRW. ON APCH TO ATL; APCH CTLR WAS BUSY. LAST ASSIGNED HDG WAS 180 DEGS; ALT WAS 6000 FT MSL. WE WERE BEING VECTORED TO RWY 26R LOC. AS WE APCHED THE LOC COURSE WE COMMENTED ON BEING L ON THE HDG. I WAS THE PNF; COULD NOT GET THROUGH TO REACH ATC. I THEN NOTICED TFC ON TCASII. I LOOKED UP TO VISUALLY ACQUIRE THE TFC WHEN WE RECEIVED THE 'TFC; TFC' AURAL MESSAGE. I INSTRUCTED THE FO TO TURN R TO JOIN THE RWY 26R LOC. I SAW A B727 AT OUR ALT IN A L TURN. HE DISAPPEARED BEHIND MY ACFT. ATC THEN CLRED US TO JOIN RWY 26R; INITIAL HDG 290 DEGS. IMMEDIATELY WE WERE GIVEN A DSCNT CLRNC TO 5000 FT THEN 4000 FT. WE PROCEEDED IN TO RWY 26R AND LANDED WITHOUT INCIDENT. WHEN BEING VECTORED FOR FINAL IN ATL; SOMETIMES YOU ARE GIVEN A HDG TO PASS THROUGH THE LOC; USUALLY FOR SPACING. IF THIS IS GOING TO HAPPEN; USUALLY THE ATC WILL TELL YOU ABOUT IT. I NOTICED US GOING THROUGH AND WAS UNABLE TO QUERY CTLR. I THOUGHT WE WERE BEING SENT THROUGH INTENTIONALLY UNTIL I SAW THE TFC ON TCASII. I THEN DECIDED TO TURN R TO JOIN THE RWY 26R LOC.