B737 crew had TCASII RA in sat class C.

Attributes
ACN	465848
Time
Date	200003
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sat.airport
State Reference	TX
Altitude	msl single value : 3000
Aircraft 1
Controlling Facilities	tracon : sat.tracon tower : sat.tower
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 30l
Flight Phase	descent : vacating altitude descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : sat.tracon tower : sat.tower
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp pilot : instrument pilot : private
Experience	flight time last 90 days : 120 flight time total : 8500 flight time type : 4500
ASRS Report	465848
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne critical non adherence : published procedure
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 12000 vertical : 500
Supplementary
Problem Areas	Airspace Structure FAA ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Inter Facility Coordination Failure

Narrative:

During switch in radio frequencys from san antonio approach control to san antonio international tower, I received a TCASII advisory and RA for a maximum climb. This occurred at 6 mi, base to final turn, 3000 ft MSL, 150 KTS, and configuring for landing. The closest I observed the TCASII intruder alert was inside 2 mi, and 500 ft low and left of our position. During the radio switch from approach to tower TCASII advised 'traffic' shortly followed by a 'climb' RA. While checking in with tower, tower advised us of several light aircraft in the area. TCASII was advising 'climb' while tower was advising us of the traffic. I began a climb to respond to TCASII commands and traffic passed off our left and low. We continued the visual approach and landing. Neither myself nor the first officer ever visually acquired the intruding aircraft. I talked by phone to the approach control supervisor after landing and he said he would check into our incident. Our problem was late notification of close-in traffic to the san antonio international airport. The disturbing thing is we don't really know how close we came to the other aircraft.

Original NASA ASRS Text

Title: B737 CREW HAD TCASII RA IN SAT CLASS C.

Narrative: DURING SWITCH IN RADIO FREQS FROM SAN ANTONIO APCH CTL TO SAN ANTONIO INTL TWR, I RECEIVED A TCASII ADVISORY AND RA FOR A MAX CLB. THIS OCCURRED AT 6 MI, BASE TO FINAL TURN, 3000 FT MSL, 150 KTS, AND CONFIGURING FOR LNDG. THE CLOSEST I OBSERVED THE TCASII INTRUDER ALERT WAS INSIDE 2 MI, AND 500 FT LOW AND L OF OUR POS. DURING THE RADIO SWITCH FROM APCH TO TWR TCASII ADVISED 'TFC' SHORTLY FOLLOWED BY A 'CLB' RA. WHILE CHKING IN WITH TWR, TWR ADVISED US OF SEVERAL LIGHT ACFT IN THE AREA. TCASII WAS ADVISING 'CLB' WHILE TWR WAS ADVISING US OF THE TFC. I BEGAN A CLB TO RESPOND TO TCASII COMMANDS AND TFC PASSED OFF OUR L AND LOW. WE CONTINUED THE VISUAL APCH AND LNDG. NEITHER MYSELF NOR THE FO EVER VISUALLY ACQUIRED THE INTRUDING ACFT. I TALKED BY PHONE TO THE APCH CTL SUPVR AFTER LNDG AND HE SAID HE WOULD CHK INTO OUR INCIDENT. OUR PROB WAS LATE NOTIFICATION OF CLOSE-IN TFC TO THE SAN ANTONIO INTL ARPT. THE DISTURBING THING IS WE DON'T REALLY KNOW HOW CLOSE WE CAME TO THE OTHER ACFT.

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.