Narrative:

FK28 was descending on visual approach C414 was VFR descending. Called traffic at 10 mi, was not talking to C414. Another controller issued traffic to C414 and told him to maintain VFR at or above 6000 ft. FK28 was out of 5800 ft descending so I called traffic again stating C414 was stopped at 6000 ft. 10 seconds later FK28 responded to a TCASII RA and climbed. C414 checked on stating 'traffic in sight -- taking action.' by then traffic had passed each other. Supplemental information from acn 346729: TCASII RA, 'climb, climb, climb' (we were descending 1000 FPM through 5800 ft). Intruder was restr by approach control to 6000 ft MSL. We initiated a climb and once committed, the RA reversed to a 'descend now, descend now' RA. The intruder said, 'I have the other aircraft and I'm taking evasive action.' when he turned to go behind us, that was the first time we saw him. It, in my opinion, was an near midair collision due to an erroneous TCASII RA. If we had not received a 'climb' RA, this would not have become a serious situation.

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Original NASA ASRS Text

Title: FK28 ON VISUAL APCH DSNDING WAS GIVEN TFC INFO ON A C414 GOING THROUGH THE AREA VFR AT 6000 FT AND WORKING A DIFFERENT APCH CTLR. THE C414 WAS GIVEN TFC INFO ON THE FK28 AND TOLD HE WAS DSNDING INTO PDX. FK28 GOT A TCASII RA AT 5800 FT TELLING HIM TO CLB AND SINCE HE DIDN'T SEE THE C414 HE FOLLOWED THE RA. RESULT WAS AN NMAC WHICH THE FK28 FLC BLAMES ON THE ERRONEOUS TCASII INFO.

Narrative: FK28 WAS DSNDING ON VISUAL APCH C414 WAS VFR DSNDING. CALLED TFC AT 10 MI, WAS NOT TALKING TO C414. ANOTHER CTLR ISSUED TFC TO C414 AND TOLD HIM TO MAINTAIN VFR AT OR ABOVE 6000 FT. FK28 WAS OUT OF 5800 FT DSNDING SO I CALLED TFC AGAIN STATING C414 WAS STOPPED AT 6000 FT. 10 SECONDS LATER FK28 RESPONDED TO A TCASII RA AND CLBED. C414 CHKED ON STATING 'TFC IN SIGHT -- TAKING ACTION.' BY THEN TFC HAD PASSED EACH OTHER. SUPPLEMENTAL INFO FROM ACN 346729: TCASII RA, 'CLB, CLB, CLB' (WE WERE DSNDING 1000 FPM THROUGH 5800 FT). INTRUDER WAS RESTR BY APCH CTL TO 6000 FT MSL. WE INITIATED A CLB AND ONCE COMMITTED, THE RA REVERSED TO A 'DSND NOW, DSND NOW' RA. THE INTRUDER SAID, 'I HAVE THE OTHER ACFT AND I'M TAKING EVASIVE ACTION.' WHEN HE TURNED TO GO BEHIND US, THAT WAS THE FIRST TIME WE SAW HIM. IT, IN MY OPINION, WAS AN NMAC DUE TO AN ERRONEOUS TCASII RA. IF WE HAD NOT RECEIVED A 'CLB' RA, THIS WOULD NOT HAVE BECOME A SERIOUS SIT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.