Narrative:

The first officer was descending, autoplt on, to 5000 ft MSL on a vector to tpa. About the same time I noticed traffic on the TCASII scope -- we got a TCASII TA. I visually acquired the traffic at 2 O'clock position and closing, an obvious conflict. It was a single engine, low wing, small airplane at about 5300 ft MSL. At this time we got a TCASII RA to climb. I took the controls and aggressively pulled up and climbed to 6000 ft MSL. The closest vertical separation observed on TCASII ws 200 ft. The small aircraft passed behind us as we climbed. Tpa approach called us about the traffic just before all the TCASII advisories were received. In fact, I responded to the radio call as we were evading the traffic. Although I believe we remained 'well clear' (500 ft metal to metal) it was close and I'm not 100% sure. The rest of the arrival was uneventful. Upon talking to the TRACON supervisor, I learned the traffic was VFR, violating class B airspace without communications. The controllers had been watching him, yet descended me into close proximity. In my opinion, the radio advisory was tardy. Just goes to show what we all know -- it pays to look outside all you can. TCASII really saved the day!

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Original NASA ASRS Text

Title: ACR FOLLOWS TCASII RA CAUSED BY LIGHT ACFT ENTRY INTO CLASS B AIRSPACE AT TPA, FL, WITHOUT CLRNC. ATC WAS AWARE BUT ISSUED LATE ADVISORY.

Narrative: THE FO WAS DSNDING, AUTOPLT ON, TO 5000 FT MSL ON A VECTOR TO TPA. ABOUT THE SAME TIME I NOTICED TFC ON THE TCASII SCOPE -- WE GOT A TCASII TA. I VISUALLY ACQUIRED THE TFC AT 2 O'CLOCK POS AND CLOSING, AN OBVIOUS CONFLICT. IT WAS A SINGLE ENG, LOW WING, SMALL AIRPLANE AT ABOUT 5300 FT MSL. AT THIS TIME WE GOT A TCASII RA TO CLB. I TOOK THE CTLS AND AGGRESSIVELY PULLED UP AND CLBED TO 6000 FT MSL. THE CLOSEST VERT SEPARATION OBSERVED ON TCASII WS 200 FT. THE SMALL ACFT PASSED BEHIND US AS WE CLBED. TPA APCH CALLED US ABOUT THE TFC JUST BEFORE ALL THE TCASII ADVISORIES WERE RECEIVED. IN FACT, I RESPONDED TO THE RADIO CALL AS WE WERE EVADING THE TFC. ALTHOUGH I BELIEVE WE REMAINED 'WELL CLR' (500 FT METAL TO METAL) IT WAS CLOSE AND I'M NOT 100% SURE. THE REST OF THE ARR WAS UNEVENTFUL. UPON TALKING TO THE TRACON SUPVR, I LEARNED THE TFC WAS VFR, VIOLATING CLASS B AIRSPACE WITHOUT COMS. THE CTLRS HAD BEEN WATCHING HIM, YET DSNDED ME INTO CLOSE PROX. IN MY OPINION, THE RADIO ADVISORY WAS TARDY. JUST GOES TO SHOW WHAT WE ALL KNOW -- IT PAYS TO LOOK OUTSIDE ALL YOU CAN. TCASII REALLY SAVED THE DAY!

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.