E120 crew had a tcasi TA with a C172 in class C airspace.

Attributes
ACN	473586
Time
Date	200005
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : tul.airport
State Reference	OK
Altitude	msl single value : 2000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : tul.tracon tower : tul.tower
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 36r other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : tul.tracon
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 150 flight time total : 3700 flight time type : 3100
ASRS Report	473586
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : multi engine pilot : commercial
Events
Anomaly	conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	flight crew : took precautionary avoidance action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 2400 vertical : 200
Supplementary
Problem Areas	ATC Human Performance FAA Airspace Structure Aircraft
Primary Problem	Ambiguous

Narrative:

On approach to tul international we were cleared to intercept the ILS runway 36R approach course and track inbound on the localizer. We were #3 on approach. We called preceding traffic and the airport in sight and were cleared for a visual approach to tul and handed off to the tower. At approximately 11.5 mi DME on the approach, we received a tcasi TA intruder at approximately 10:30 O'clock position and -300 ft. I visually found the intruder (C172) and asked the PF to stop her descent. Last observed TCASII reading was -200 ft as I watched the C172 go under us. I reported traffic to the tower and I was told by the tower that approach was working the traffic and that the traffic had called us in sight and was maintaining visual separation. We were never informed about the traffic from approach control. I phoned the local supervisor after landing and was told by him also that the C172 had called us in sight and was maintaining visual separation.

Original NASA ASRS Text

Title: E120 CREW HAD A TCASI TA WITH A C172 IN CLASS C AIRSPACE.

Narrative: ON APCH TO TUL INTL WE WERE CLRED TO INTERCEPT THE ILS RWY 36R APCH COURSE AND TRACK INBOUND ON THE LOC. WE WERE #3 ON APCH. WE CALLED PRECEDING TFC AND THE ARPT IN SIGHT AND WERE CLRED FOR A VISUAL APCH TO TUL AND HANDED OFF TO THE TWR. AT APPROX 11.5 MI DME ON THE APCH, WE RECEIVED A TCASI TA INTRUDER AT APPROX 10:30 O'CLOCK POS AND -300 FT. I VISUALLY FOUND THE INTRUDER (C172) AND ASKED THE PF TO STOP HER DSCNT. LAST OBSERVED TCASII READING WAS -200 FT AS I WATCHED THE C172 GO UNDER US. I RPTED TFC TO THE TWR AND I WAS TOLD BY THE TWR THAT APCH WAS WORKING THE TFC AND THAT THE TFC HAD CALLED US IN SIGHT AND WAS MAINTAINING VISUAL SEPARATION. WE WERE NEVER INFORMED ABOUT THE TFC FROM APCH CTL. I PHONED THE LCL SUPVR AFTER LNDG AND WAS TOLD BY HIM ALSO THAT THE C172 HAD CALLED US IN SIGHT AND WAS MAINTAINING VISUAL SEPARATION.

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.