FK10 CREW HAD A TCASII RA.

Narrative

FLYING THE BLEWE 1 ARR; ATC GAVE US A DSCNT TO CROSS THE SEWZY INTXN AT 13000 FT. DSNDING THROUGH FL180 AT 2000 FPM; WE RECEIVED A TA INDICATING THERE WAS AN ACFT 500 FT BELOW US. I DISCONNECTED THE AUTOPLT AND BEGAN TO LEVEL THE ACFT WHEN AT APPROX 17800 FT WE RECEIVED AN RA TO CLB. I BEGAN CLBING THE ACFT TO COMPLY WITH THE RA WHILE MY FO CALLED ATC ADVISING THEM OF OUR ACTIONS AND ASKING THEM ABOUT THE TFC. MY NAV DISPLAY WAS POSITIONED ON THE 60 NM RANGE AND THE ACFT APPEARED DIRECTLY BELOW US. AT NO TIME HAD WE RECEIVED AN ADVISORY OF THIS ACFT FROM ATC. AFTER OUR CALL; THE CTLR TOLD US THE ACFT WAS VFR LEVEL AT 17500 FT AND WAS NOT A PROB. HE THEN ASKED WHICH WAY WE WERE DEVIATING. WE TOLD HIM WE WERE CLBING. HE THEN ASKED US TO RESUME OUR DSCNT TO CROSS SEWZY AT 13000 FT. I THEN GOT ON THE RADIO AND RESPONDED THAT I THOUGHT THE ACFT WAS IN FACT A PROB WHEN I WAS DSNDING THROUGH HIS ALT AT 2000 FPM. AT 13 DME FROM SEWZY THE RA QUIT AND WE RESUMED OUR DSCNT. CTLR SAID HE WAS BUSY SO THERE WAS NO FURTHER DISCUSSION AND WE WERE GIVEN A FREQ CHANGE.