Large transport has near midair collision with small aircraft in the small aircraft area.

Attributes
ACN	179502
Time
Date	199105
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sxc
State Reference	CA
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sna
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	descent other
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	179502
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 200 flight time total : 12000 flight time type : 1200
ASRS Report	179503
Events
Anomaly	conflict : nmac
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	Other
Miss Distance	horizontal : 500 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

While level at 5000', 250 KIAS, heading 070 degrees, being controled by coast approach frequency 127.2, we were advised of a VFR target, 2-3 O'clock, 1 mi, northbound at 5400'. (General location: over water approximately the sxc 040 degree right, approximately 20 NM). We responded, 'no contact, keep us advised.' next communication from controller was, 'target now at 12 O'clock,' at which time we first acquired the target, an small aircraft co-altitude, directly in front of us, gradually descending through 5000', crossing right to left. We continued with no evasive action, informed coast approach of near miss. Closest point of approach occurred as we passed behind the target, it passing our left wing approximately 500' horizontal and 200' below us. The follow-up advisory by the controller was the most significant event leading us to target acquisition. So often a request to 'keep us advised' goes unheeded. In this case, the professionalism of the controller played the most significant role.

Original NASA ASRS Text

Title: LGT HAS NMAC WITH SMA IN THE SMA AREA.

Narrative: WHILE LEVEL AT 5000', 250 KIAS, HDG 070 DEGS, BEING CTLED BY COAST APCH FREQ 127.2, WE WERE ADVISED OF A VFR TARGET, 2-3 O'CLOCK, 1 MI, NBND AT 5400'. (GENERAL LOCATION: OVER WATER APPROX THE SXC 040 DEG R, APPROX 20 NM). WE RESPONDED, 'NO CONTACT, KEEP US ADVISED.' NEXT COM FROM CTLR WAS, 'TARGET NOW AT 12 O'CLOCK,' AT WHICH TIME WE FIRST ACQUIRED THE TARGET, AN SMA CO-ALT, DIRECTLY IN FRONT OF US, GRADUALLY DSNDING THROUGH 5000', XING RIGHT TO LEFT. WE CONTINUED WITH NO EVASIVE ACTION, INFORMED COAST APCH OF NEAR MISS. CLOSEST POINT OF APCH OCCURRED AS WE PASSED BEHIND THE TARGET, IT PASSING OUR LEFT WING APPROX 500' HORIZ AND 200' BELOW US. THE FOLLOW-UP ADVISORY BY THE CTLR WAS THE MOST SIGNIFICANT EVENT LEADING US TO TARGET ACQUISITION. SO OFTEN A REQUEST TO 'KEEP US ADVISED' GOES UNHEEDED. IN THIS CASE, THE PROFESSIONALISM OF THE CTLR PLAYED THE MOST SIGNIFICANT ROLE.

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.