A320 HAS NMAC WITH UNRPTED AND NOT TCASII TFC WHILE ON ILS APCH INTO COS.

Narrative

MSP TO COS ON AUG/TUE/99. WE WERE IN AN A320 ACFT FLYING THE ILS/DME APCH TO RWY 17L AT COLORADO SPRINGS. THE TIME WAS APPROX XA15 PM LCL. THE AUTOPLT AND AUTOTHRUST SYS WERE ENGAGED AND THE AIRPLANE WAS COUPLED UP TO THE ILS. AT APPROX 1000 FT AGL; 3 MI FROM THE END OF THE RWY; I NOTICED SOMETHING OUT OF THE CORNER OF MY L SIDE WINDOW. I TURNED MY HEAD AND SAW A SMALL; LOW-WING; SINGLE-ENG AIRPLANE HEADING RIGHT TOWARDS US. THE ACFT WAS HEADING APPROX 270 DEGS MAGNETIC; 90 DEGS OR SO TO MY HEADING; SLIGHTLY ABOVE OUR ALT. OUR TCASII WARNING SYS DID NOT GO OFF OR ISSUE ANY WARNING; NOR WAS THE TFC DISPLAYED. IT APPEARED TO ME THAT THE ACFT DID NOT SEE US AND WAS ON A HEADING THAT COULD COME VERY CLOSE TO HITTING US. I IMMEDIATELY DISCONNECTED THE AUTOPLT AND BANKED MY ACFT TO THE R AND DSNDED. I LOST APPROX 200 FT IN THE AVOIDANCE MANEUVER AND TURNED APPROX 20 DEGS OFF HEADING. I THEN LEVELED MY WINGS AND SAW THAT THE TFC ACFT WAS GOING TO PASS ABOVE US; SLIGHTLY BEHIND US. I THEN CORRECTED BACK TO THE ILS LOC AND GS AND LANDED NORMALLY. I ASKED THE TWR CTLR AT COS TWICE ABOUT THE TFC ACFT BEFORE WE TOUCHED DOWN ON THE RWY; BUT WE RECEIVED NO RESPONSE AT ALL FROM TWR. IT APPEARED THAT THE TFC ACFT CONTINUED ON A 270 DEG COURSE AND TURNED A L BASE FOR THE PARALLEL RWY 17R AND LANDED A FEW MINS AFTER US. IT APPEARED THAT HIS CALL SIGN WAS ACFT Y. I ASKED THE TWR/GND CTLRS IF THIS WAS TRUE; BUT THEY WOULD NOT RESPOND. AFTER ARRIVING AT THE GATE; I CALLED THE TWR AND SPOKE TO THE SUPVR ON DUTY AND HE SAID THAT HE WAS INFORMED THAT ACFT Y HAD SOME RADIO/ELECTRICAL PROBS AND ALSO HAD NO XPONDER. HE SAID THAT ACFT Y WAS TALKING ON A BACKUP HAND-HELD RADIO. I ASKED THE SUPVR IF THE COS TWR HAD RADAR; AND HE REPLIED THAT YES THEY DID AND THAT HE BELIEVED THAT THE CONFLICTING TFC ACFT SHOULD HAVE BEEN ON THEIR RADAR AS AT LEAST A 'PRIMARY TARGET.' I ASKED IF THE TWR WOULD NORMALLY CALL OUT SUCH TFC TO AN AIRLINER ON AN ILS APCH AND HE REPLIED YES. I NOTIFIED THE SUPVR OF MY REQUIREMENT TO RPT THIS NEAR MIDAIR TO MY CHIEF DISPATCHER AND CHIEF PLT; AND TO ALSO FILL OUT AN ASR RPT.