Large transport small aircraft near midair collision in the sna air traffic area.

Attributes
ACN	179506
Time
Date	199105
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sna
State Reference	CA
Altitude	msl bound lower : 1800 msl bound upper : 1800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sna
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 240 flight time total : 6300 flight time type : 2500
ASRS Report	179506
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 200 flight time total : 12000 flight time type : 1200
ASRS Report	179504
Events
Anomaly	conflict : nmac non adherence : far
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 200 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

While proceeding downwind for an approach to sna 19R at 3000', 160 KIAS, heading 030 degrees, being controled by sna tower, we were advised of a VFR target, 12 O'clock, 1 mi nebnd at 1800' (general location northwest of field, sna 330 degrees at 1 mi). Having the field in sight, the tower cleared us for a visibility approach to 19R. While maintain a visibility alert, a descent was commenced. Approaching 1800' with no target in sight, the first officer asked tower for further advisories while the captain initiated a turn to a right base in an attempt to stay 'inside' of the as yet unseen target. Target was first acquired by the first officer below and to the right at our 4 O'clock approximately 200'. It is likely the other aircraft took evasive action after we passed and in so doing proceeded to pass behind us. Though not required to do so, the radar advisories provided by the tower contributed significantly to an already heightened awareness by the cockpit crew, and was most appreciated.

Original NASA ASRS Text

Title: LGT SMA NMAC IN THE SNA ATA.

Narrative: WHILE PROCEEDING DOWNWIND FOR AN APCH TO SNA 19R AT 3000', 160 KIAS, HDG 030 DEGS, BEING CTLED BY SNA TWR, WE WERE ADVISED OF A VFR TARGET, 12 O'CLOCK, 1 MI NEBND AT 1800' (GENERAL LOCATION NW OF FIELD, SNA 330 DEGS AT 1 MI). HAVING THE FIELD IN SIGHT, THE TWR CLRED US FOR A VIS APCH TO 19R. WHILE MAINTAIN A VIS ALERT, A DSNT WAS COMMENCED. APCHING 1800' WITH NO TARGET IN SIGHT, THE F/O ASKED TWR FOR FURTHER ADVISORIES WHILE THE CAPT INITIATED A TURN TO A RIGHT BASE IN AN ATTEMPT TO STAY 'INSIDE' OF THE AS YET UNSEEN TARGET. TARGET WAS FIRST ACQUIRED BY THE F/O BELOW AND TO THE RIGHT AT OUR 4 O'CLOCK APPROX 200'. IT IS LIKELY THE OTHER ACFT TOOK EVASIVE ACTION AFTER WE PASSED AND IN SO DOING PROCEEDED TO PASS BEHIND US. THOUGH NOT REQUIRED TO DO SO, THE RADAR ADVISORIES PROVIDED BY THE TWR CONTRIBUTED SIGNIFICANTLY TO AN ALREADY HEIGHTENED AWARENESS BY THE COCKPIT CREW, AND WAS MOST APPRECIATED.

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.