Narrative:

We were on the runway 32 localizer back course runway 32 mfr, or. Just inside ashie as we descended below 9000 ft, we broke out of the clouds, and were cleared for the visual approach to runway 32. About 9 mi out as we descended through 7000 ft MSL, approach pointed out a cessna to us at 5500 ft and 3-4 mi at our 2 O'clock position. As we continued to descend, approach asked us if we still had the traffic. We had lost him but still had him on TCASII at our 3 O'clock and 700-800 ft below us at a range of about 1 mi. Approach pointed him out and we made visual contact. It became visually obvious that we would pass ahead of him at his altitude but closer than we wanted to be, so we slowed our rate of descent. About this time our TCASII gave us a traffic alert followed by an RA to decrease rate of descent, which we did. We continued on the localizer back course and kept him in sight until he passed behind us. He was never in radio contact with either cascade approach or medford tower. He continued on his route of flight at 5500 ft. In retrospect, I would have (should have) broken off the visual approach and come back around. Although I believe there never was any possibility of us passing closer than 700-800 ft vertically and 1/4 - 1/2 mi horizontally, that close is too close for me.

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Original NASA ASRS Text

Title: FLC OF A B737 SLOWED RATE OF DSCNT DURING A VISUAL LOC BACK COURSE APCH IN RESPONSE TO A TA, AND A VISUAL SIGHTING OF THE TFC. IN ADDITION, TCASII KEPT RPTR INFORMED AS TO THE EXACT LOCATION AND RELATIONSHIP TO THEIR POS.

Narrative: WE WERE ON THE RWY 32 LOC BACK COURSE RWY 32 MFR, OR. JUST INSIDE ASHIE AS WE DSNDED BELOW 9000 FT, WE BROKE OUT OF THE CLOUDS, AND WERE CLRED FOR THE VISUAL APCH TO RWY 32. ABOUT 9 MI OUT AS WE DSNDED THROUGH 7000 FT MSL, APCH POINTED OUT A CESSNA TO US AT 5500 FT AND 3-4 MI AT OUR 2 O'CLOCK POS. AS WE CONTINUED TO DSND, APCH ASKED US IF WE STILL HAD THE TFC. WE HAD LOST HIM BUT STILL HAD HIM ON TCASII AT OUR 3 O'CLOCK AND 700-800 FT BELOW US AT A RANGE OF ABOUT 1 MI. APCH POINTED HIM OUT AND WE MADE VISUAL CONTACT. IT BECAME VISUALLY OBVIOUS THAT WE WOULD PASS AHEAD OF HIM AT HIS ALT BUT CLOSER THAN WE WANTED TO BE, SO WE SLOWED OUR RATE OF DSCNT. ABOUT THIS TIME OUR TCASII GAVE US A TFC ALERT FOLLOWED BY AN RA TO DECREASE RATE OF DSCNT, WHICH WE DID. WE CONTINUED ON THE LOC BACK COURSE AND KEPT HIM IN SIGHT UNTIL HE PASSED BEHIND US. HE WAS NEVER IN RADIO CONTACT WITH EITHER CASCADE APCH OR MEDFORD TWR. HE CONTINUED ON HIS RTE OF FLT AT 5500 FT. IN RETROSPECT, I WOULD HAVE (SHOULD HAVE) BROKEN OFF THE VISUAL APCH AND COME BACK AROUND. ALTHOUGH I BELIEVE THERE NEVER WAS ANY POSSIBILITY OF US PASSING CLOSER THAN 700-800 FT VERTLY AND 1/4 - 1/2 MI HORIZLY, THAT CLOSE IS TOO CLOSE FOR ME.

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.