Air carrier on approach has near midair collision with small aircraft.

Attributes
ACN	161147
Time
Date	199010
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sna
State Reference	CA
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : sna
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach descent other
Route In Use	arrival other 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 : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : commercial pilot : flight engineer
Experience	flight time last 90 days : 200 flight time total : 14000 flight time type : 3300
ASRS Report	161147
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp pilot : cfi
Experience	flight time last 90 days : 220 flight time total : 10500 flight time type : 750
ASRS Report	161151
Events
Anomaly	conflict : nmac other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action none taken : insufficient time
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 125 vertical : 20
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

During the approach into sna I was turning from an 080 degree heading to a 210 degree heading to intercept the ILS to 19R. We were at 4000' MSL and at 140 KTS (assigned). During the turn, passing about 180 degrees, a westbound aircraft flew across the nose of our aircraft. It appeared he may have seen us as he passed in front of us, because he seemed to increase his rate of descent. I stopped the turn by disengaging the autoplt and starting an immediate left turn. We feel the aircraft, which appeared to be an small aircraft-a or small aircraft-B, passed about 100-150' in front of us. We asked coast approach control about the aircraft and he indicated the closest traffic was a target 2 mi west of us. We saw the lights of the aircraft as I made the turn, about 10 seconds before the near miss. Because of the darkness and the hazy conditions, the lights appeared to be those of a large commercial airliner that would pass over us. When I looked back at the aircraft I realized it was an small aircraft that was going to descend across our flight path.

Original NASA ASRS Text

Title: ACR ON APCH HAS NMAC WITH SMA.

Narrative: DURING THE APCH INTO SNA I WAS TURNING FROM AN 080 DEG HDG TO A 210 DEG HDG TO INTERCEPT THE ILS TO 19R. WE WERE AT 4000' MSL AND AT 140 KTS (ASSIGNED). DURING THE TURN, PASSING ABOUT 180 DEGS, A WBND ACFT FLEW ACROSS THE NOSE OF OUR ACFT. IT APPEARED HE MAY HAVE SEEN US AS HE PASSED IN FRONT OF US, BECAUSE HE SEEMED TO INCREASE HIS RATE OF DSNT. I STOPPED THE TURN BY DISENGAGING THE AUTOPLT AND STARTING AN IMMEDIATE LEFT TURN. WE FEEL THE ACFT, WHICH APPEARED TO BE AN SMA-A OR SMA-B, PASSED ABOUT 100-150' IN FRONT OF US. WE ASKED COAST APCH CTL ABOUT THE ACFT AND HE INDICATED THE CLOSEST TFC WAS A TARGET 2 MI W OF US. WE SAW THE LIGHTS OF THE ACFT AS I MADE THE TURN, ABOUT 10 SECS BEFORE THE NEAR MISS. BECAUSE OF THE DARKNESS AND THE HAZY CONDITIONS, THE LIGHTS APPEARED TO BE THOSE OF A LARGE COMMERCIAL AIRLINER THAT WOULD PASS OVER US. WHEN I LOOKED BACK AT THE ACFT I REALIZED IT WAS AN SMA THAT WAS GOING TO DSND ACROSS OUR FLT PATH.

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.