Close proximity commuter light transport-unk 3 NM south of lgb working sna.

Attributes
ACN	116794
Time
Date	198907
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : lgb
State Reference	CA
Altitude	msl bound lower : 6000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sna
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 135 flight time total : 2900 flight time type : 369
ASRS Report	116794
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 0 vertical : 250
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

We were given a turn from 180 to 120 degree while in a descent to 5000'. The captain noticed an aircraft climbing at our 11 O'clock position and approximately 1 mi. He initiated a climb to avoid the aircraft. Our altitude was 6100' when we crossed over the top of the other aircraft. I immediately asked the controller why he didn't report the traffic to us. The controller responded, telling us there was no target on the screen. A newer more advanced radar system in the los angeles basin is needed and would prevent a recurrence from happening.

Original NASA ASRS Text

Title: CLOSE PROX COMMUTER LTT-UNK 3 NM SOUTH OF LGB WORKING SNA.

Narrative: WE WERE GIVEN A TURN FROM 180 TO 120 DEG WHILE IN A DESCENT TO 5000'. THE CAPT NOTICED AN ACFT CLIMBING AT OUR 11 O'CLOCK POSITION AND APPROX 1 MI. HE INITIATED A CLIMB TO AVOID THE ACFT. OUR ALT WAS 6100' WHEN WE CROSSED OVER THE TOP OF THE OTHER ACFT. I IMMEDIATELY ASKED THE CTLR WHY HE DIDN'T REPORT THE TFC TO US. THE CTLR RESPONDED, TELLING US THERE WAS NO TARGET ON THE SCREEN. A NEWER MORE ADVANCED RADAR SYSTEM IN THE LOS ANGELES BASIN IS NEEDED AND WOULD PREVENT A RECURRENCE FROM HAPPENING.

Data retrieved from NASA's ASRS site as of August 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.