Narrative:

TCASII save. We were cleared for the four stacks visual approach to runway 15 at bur. The first officer was flying. We turned final just about 3000 ft, and on a good glide path when tower pointed out traffic at our 2 O'clock position, orbiting at 2100 ft just north of the approach course. We told him we were looking, and continued descent at about 800 FPM, in the process of configuring. I continued to look for the reported traffic as I could see him on the TCASII display, and it appeared our courses were converging and we were descending toward his altitude. We never acquired the target visually, but received a traffic alert which rapidly became an RA of 'monitor vertical speed' and it displayed to level at 200 FPM climb green arc. I instructed the first officer to respond immediately (leveloff or climb) which he did. Perhaps 1 second later, the RA changed to 'climb, climb now' and we began to rotate for a go around/climb as required, with the TCASII commanding a climb rate of 2000 FPM. 2 seconds later, it became a clear of conflict. I have imbedded in my memory that the red box showed 200 ft below us, with the symbol in contact with our aircraft symbol with the display on the 5 mi range. There was a blip on the radio altimeter, which was already alive, but only for a flash. Bur tower called about that time and asked if we thought we would be able to get down from our present position, and this being the first free moment I had, I explained that we were in the process of going around, that we'd had an RA, and could not land out of the approach. He excitedly said 'I called that traffic out to you,' to which I responded that he had, but we never saw him and we'd received the RA and had responded. We then stayed with tower for a right downwind visual to runway 8. It's only in filling out the TCASII survey after the fact that I realize how very close this event may have been. At the time, it was a matter of responding, and subsequent duties, etc, that delayed my detailed recounting of this event. But I can very vividly recall in detail the progress of our targets closing, and the relative distance in altitude, and I feel that had it not been for the TCASII system, we could very well have hit this small aircraft, and that the other aircraft was on the final approach course, though about 7 mi from the field, so probably outside the air traffic area. Being on a visual approach, and having tower call out the traffic, certainly primed me for escaping from the situation, but the TCASII display and subsequent advisories were an immeasurable aid.

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Original NASA ASRS Text

Title: MD80 CREW HAD AN NMAC WHILE FLYING THE 4 STACKS CHARTED VISUAL APCH INTO BUR.

Narrative: TCASII SAVE. WE WERE CLRED FOR THE FOUR STACKS VISUAL APCH TO RWY 15 AT BUR. THE FO WAS FLYING. WE TURNED FINAL JUST ABOUT 3000 FT, AND ON A GOOD GLIDE PATH WHEN TWR POINTED OUT TFC AT OUR 2 O'CLOCK POS, ORBITING AT 2100 FT JUST N OF THE APCH COURSE. WE TOLD HIM WE WERE LOOKING, AND CONTINUED DSCNT AT ABOUT 800 FPM, IN THE PROCESS OF CONFIGURING. I CONTINUED TO LOOK FOR THE RPTED TFC AS I COULD SEE HIM ON THE TCASII DISPLAY, AND IT APPEARED OUR COURSES WERE CONVERGING AND WE WERE DSNDING TOWARD HIS ALT. WE NEVER ACQUIRED THE TARGET VISUALLY, BUT RECEIVED A TFC ALERT WHICH RAPIDLY BECAME AN RA OF 'MONITOR VERT SPD' AND IT DISPLAYED TO LEVEL AT 200 FPM CLB GREEN ARC. I INSTRUCTED THE FO TO RESPOND IMMEDIATELY (LEVELOFF OR CLB) WHICH HE DID. PERHAPS 1 SECOND LATER, THE RA CHANGED TO 'CLB, CLB NOW' AND WE BEGAN TO ROTATE FOR A GAR/CLB AS REQUIRED, WITH THE TCASII COMMANDING A CLB RATE OF 2000 FPM. 2 SECONDS LATER, IT BECAME A CLR OF CONFLICT. I HAVE IMBEDDED IN MY MEMORY THAT THE RED BOX SHOWED 200 FT BELOW US, WITH THE SYMBOL IN CONTACT WITH OUR ACFT SYMBOL WITH THE DISPLAY ON THE 5 MI RANGE. THERE WAS A BLIP ON THE RADIO ALTIMETER, WHICH WAS ALREADY ALIVE, BUT ONLY FOR A FLASH. BUR TWR CALLED ABOUT THAT TIME AND ASKED IF WE THOUGHT WE WOULD BE ABLE TO GET DOWN FROM OUR PRESENT POS, AND THIS BEING THE FIRST FREE MOMENT I HAD, I EXPLAINED THAT WE WERE IN THE PROCESS OF GOING AROUND, THAT WE'D HAD AN RA, AND COULD NOT LAND OUT OF THE APCH. HE EXCITEDLY SAID 'I CALLED THAT TFC OUT TO YOU,' TO WHICH I RESPONDED THAT HE HAD, BUT WE NEVER SAW HIM AND WE'D RECEIVED THE RA AND HAD RESPONDED. WE THEN STAYED WITH TWR FOR A R DOWNWIND VISUAL TO RWY 8. IT'S ONLY IN FILLING OUT THE TCASII SURVEY AFTER THE FACT THAT I REALIZE HOW VERY CLOSE THIS EVENT MAY HAVE BEEN. AT THE TIME, IT WAS A MATTER OF RESPONDING, AND SUBSEQUENT DUTIES, ETC, THAT DELAYED MY DETAILED RECOUNTING OF THIS EVENT. BUT I CAN VERY VIVIDLY RECALL IN DETAIL THE PROGRESS OF OUR TARGETS CLOSING, AND THE RELATIVE DISTANCE IN ALT, AND I FEEL THAT HAD IT NOT BEEN FOR THE TCASII SYS, WE COULD VERY WELL HAVE HIT THIS SMALL ACFT, AND THAT THE OTHER ACFT WAS ON THE FINAL APCH COURSE, THOUGH ABOUT 7 MI FROM THE FIELD, SO PROBABLY OUTSIDE THE ATA. BEING ON A VISUAL APCH, AND HAVING TWR CALL OUT THE TFC, CERTAINLY PRIMED ME FOR ESCAPING FROM THE SIT, BUT THE TCASII DISPLAY AND SUBSEQUENT ADVISORIES WERE AN IMMEASURABLE AID.

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.