Narrative:

Air carrier X given a descent to 2500 ft on a heading of 070 degrees. The first officer, who was flying (and was very experienced) stated that he had the field in sight (to me). Approach then stated that we were following a B-737 turning base at 1 O'clock and to report him insight. I replied, 'we have an aircraft in sight.' approach then said, follow and maintain visual separation -- you are cleared for a visual runway 24R.' when turning base at 2500 ft and 1 NM from the field, we could not see the field because of the haze. I asked approach, 'where is our traffic?' approach said, 'do you have the traffic in sight?' I asked my first officer if he still had the other aircraft, and he said, 'I lost him.' I reported this to approach, and they said, 'turn right to 360 degrees, maintain 2500 ft.' we then received a turn to 070 degrees, and received an RA to 'climb,' and we did, to 2700 ft, until the warning ceased. I informed the controller that we had done this, and he said, 'tell me if you are doing that, because I had traffic descending above you.' I did not respond, because the controller was obviously overloaded. The controller then gave us a traffic (aircraft Y) 500 ft below, which we visually acquired. We were then vectored for the ILS runway 24R approach and landing. In this case, the controller did not attempt to 'force' the visual and bailed us out for the ILS. Because he was overloaded, he did not give us TA's until after I reported the RA.

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Original NASA ASRS Text

Title: ACR X TCASII RA WITH VFR ACFT Y DISRUPTIVE TO ATC. EVASIVE ACTION CLB.

Narrative: ACR X GIVEN A DSCNT TO 2500 FT ON A HDG OF 070 DEGS. THE FO, WHO WAS FLYING (AND WAS VERY EXPERIENCED) STATED THAT HE HAD THE FIELD IN SIGHT (TO ME). APCH THEN STATED THAT WE WERE FOLLOWING A B-737 TURNING BASE AT 1 O'CLOCK AND TO RPT HIM INSIGHT. I REPLIED, 'WE HAVE AN ACFT IN SIGHT.' APCH THEN SAID, FOLLOW AND MAINTAIN VISUAL SEPARATION -- YOU ARE CLRED FOR A VISUAL RWY 24R.' WHEN TURNING BASE AT 2500 FT AND 1 NM FROM THE FIELD, WE COULD NOT SEE THE FIELD BECAUSE OF THE HAZE. I ASKED APCH, 'WHERE IS OUR TFC?' APCH SAID, 'DO YOU HAVE THE TFC IN SIGHT?' I ASKED MY FO IF HE STILL HAD THE OTHER ACFT, AND HE SAID, 'I LOST HIM.' I RPTED THIS TO APCH, AND THEY SAID, 'TURN R TO 360 DEGS, MAINTAIN 2500 FT.' WE THEN RECEIVED A TURN TO 070 DEGS, AND RECEIVED AN RA TO 'CLB,' AND WE DID, TO 2700 FT, UNTIL THE WARNING CEASED. I INFORMED THE CTLR THAT WE HAD DONE THIS, AND HE SAID, 'TELL ME IF YOU ARE DOING THAT, BECAUSE I HAD TFC DSNDING ABOVE YOU.' I DID NOT RESPOND, BECAUSE THE CTLR WAS OBVIOUSLY OVERLOADED. THE CTLR THEN GAVE US A TFC (ACFT Y) 500 FT BELOW, WHICH WE VISUALLY ACQUIRED. WE WERE THEN VECTORED FOR THE ILS RWY 24R APCH AND LNDG. IN THIS CASE, THE CTLR DID NOT ATTEMPT TO 'FORCE' THE VISUAL AND BAILED US OUT FOR THE ILS. BECAUSE HE WAS OVERLOADED, HE DID NOT GIVE US TA'S UNTIL AFTER I RPTED THE RA.

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.