MD80 crew had TCASII RA with unknown aircraft while departing lgb.

Attributes
ACN	524259
Time
Date	200109
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : lgb.airport
State Reference	CA
Altitude	msl single value : 1200
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sct.tracon tracon : n90.tracon
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude climbout : initial
Route In Use	departure : noise abatement departure sid : ns
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : sct.tracon
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise : level
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	524259
Person 2
Affiliation	company : air carrier
Function	controller : local
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	flight crew : took evasive action none taken : detected after the fact
Consequence	other
Supplementary
Problem Areas	Aircraft Airspace Structure FAA Flight Crew Human Performance ATC Human Performance ATC Facility
Primary Problem	Flight Crew Human Performance
Situations
ATC Facility	procedure or policy : sct.tracon
Airport	procedure or policy : lgb.airport

Narrative:

Descend RA on takeoff. After takeoff at lgb, during a left turn to 180 degrees. At approximately 1200 ft, we received an RA to descend. I initiated a descent and the first officer and myself looked for the traffic. The first officer also called the position from TCASII. Neither of us saw traffic and the TCASII called 'clear of conflict' very shortly. I was reluctant to descend too rapidly at our altitude, and was also concerned that we might have caused a noise violation.

Original NASA ASRS Text

Title: MD80 CREW HAD TCASII RA WITH UNKNOWN ACFT WHILE DEPARTING LGB.

Narrative: DSND RA ON TKOF. AFTER TKOF AT LGB, DURING A L TURN TO 180 DEGS. AT APPROX 1200 FT, WE RECEIVED AN RA TO DSND. I INITIATED A DSCNT AND THE FO AND MYSELF LOOKED FOR THE TFC. THE FO ALSO CALLED THE POS FROM TCASII. NEITHER OF US SAW TFC AND THE TCASII CALLED 'CLR OF CONFLICT' VERY SHORTLY. I WAS RELUCTANT TO DSND TOO RAPIDLY AT OUR ALT, AND WAS ALSO CONCERNED THAT WE MIGHT HAVE CAUSED A NOISE VIOLATION.

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.