B737-700 receives TCAS RA during descent on right downwind to runway 19R at sna.

Attributes
ACN	697232
Time
Date	200605
Place
Locale Reference	airport : sna.airport
State Reference	CA
Altitude	msl single value : 5000
Environment
Flight Conditions	VMC
Weather Elements	other
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sct.tracon tower : atl.tower
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : visual arrival : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Bellanca Aircraft Corp Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 200 flight time total : 800 flight time type : 5000
ASRS Report	697232
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	697231
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 800
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor Airspace Structure ATC Human Performance
Primary Problem	Ambiguous

Narrative:

While on a downwind assigned vector for sna runway 19R; we were given a traffic call. ATC advised a VFR bellanca at 4500 ft; 12 O'clock position. I don't recall the distance. A few seconds later we got a TCAS RA to climb. We 1) initiated the RA climb response to set a vvi above the red region about 1500 ft I recall. We got the 'clear of conflict' about 5800 ft and initiated a leveloff and descent back to 5000 ft by ATC request. In the descent we were cleared to 3000 ft and continued the vectors to visual approach uneventfully. Upon landing; ground control advised us to call coast area supervisor. The captain called and the conversation with the supervisor did not leave us with a comfortable feeling about his understanding of our procedures. He (according to the captain) seemed to disagree with our actions stating that we interfered with traffic at other altitudes. He said he was going to 'address this problem.' we are not sure what he meant by that or what his intentions are. The area was hazy and we never did get a visual on the traffic. With the volume of traffic in this area and the IFR corridors; one has to wonder why VFR aircraft are transiting this area at 4500 ft.

Original NASA ASRS Text

Title: B737-700 RECEIVES TCAS RA DURING DSCNT ON R DOWNWIND TO RWY 19R AT SNA.

Narrative: WHILE ON A DOWNWIND ASSIGNED VECTOR FOR SNA RWY 19R; WE WERE GIVEN A TFC CALL. ATC ADVISED A VFR BELLANCA AT 4500 FT; 12 O'CLOCK POS. I DON'T RECALL THE DISTANCE. A FEW SECONDS LATER WE GOT A TCAS RA TO CLB. WE 1) INITIATED THE RA CLB RESPONSE TO SET A VVI ABOVE THE RED REGION ABOUT 1500 FT I RECALL. WE GOT THE 'CLR OF CONFLICT' ABOUT 5800 FT AND INITIATED A LEVELOFF AND DSCNT BACK TO 5000 FT BY ATC REQUEST. IN THE DSCNT WE WERE CLRED TO 3000 FT AND CONTINUED THE VECTORS TO VISUAL APCH UNEVENTFULLY. UPON LNDG; GND CTL ADVISED US TO CALL COAST AREA SUPVR. THE CAPT CALLED AND THE CONVERSATION WITH THE SUPVR DID NOT LEAVE US WITH A COMFORTABLE FEELING ABOUT HIS UNDERSTANDING OF OUR PROCS. HE (ACCORDING TO THE CAPT) SEEMED TO DISAGREE WITH OUR ACTIONS STATING THAT WE INTERFERED WITH TFC AT OTHER ALTS. HE SAID HE WAS GOING TO 'ADDRESS THIS PROB.' WE ARE NOT SURE WHAT HE MEANT BY THAT OR WHAT HIS INTENTIONS ARE. THE AREA WAS HAZY AND WE NEVER DID GET A VISUAL ON THE TFC. WITH THE VOLUME OF TFC IN THIS AREA AND THE IFR CORRIDORS; ONE HAS TO WONDER WHY VFR ACFT ARE TRANSITING THIS AREA AT 4500 FT.

Data retrieved from NASA's ASRS site as of January 2009 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.