Narrative:

I was captain on flight ont to san. On departure at an intermediate level off of 4000' MSL we were turning to intercept the 130 right outbnd from the pdz VOR. Our TCAS unit issued a 'TA', immediately followed by an 'RA'. We located the traffic and initiated evasive action, a descent of approximately 400'. The conflicting aircraft was an small aircraft going east to west over the pdz VOR. We passed slightly behind and below the small aircraft. TCAS indicated we were 400' below the aircraft as it passed overhead. We advised ATC that we had taken evasive action descending 400' below our assigned altitude. ATC did not advise us of this conflict. There were a large number of aircraft in the vicinity. Our TCAS on a ten mi range displayed 5 additional aircraft at the time of the incident. I'm sure the controller's radar screen was a wash with traffic. The TCAS worked wonderfully; although the audio was a bit too loud (loud enough to alarm the passengers in first class!). I was glad the system was operational. TCAS not only pointed out the conflict faster than visibility acquisition, but also made our evasive actions smoother and more tempered as to not creating additional conflicts with other aircraft in the same airspace.

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Original NASA ASRS Text

Title: DEPARTING ONT OVER PDZ FLT CREW OF MLG HAD TCASII RA, DESCEND, DESCENDED 400' AND OBSERVED SMA PASS IN CLOSE PROX 400' OVERHEAD.

Narrative: I WAS CAPT ON FLT ONT TO SAN. ON DEP AT AN INTERMEDIATE LEVEL OFF OF 4000' MSL WE WERE TURNING TO INTERCEPT THE 130 R OUTBND FROM THE PDZ VOR. OUR TCAS UNIT ISSUED A 'TA', IMMEDIATELY FOLLOWED BY AN 'RA'. WE LOCATED THE TFC AND INITIATED EVASIVE ACTION, A DSNT OF APPROX 400'. THE CONFLICTING ACFT WAS AN SMA GOING E TO W OVER THE PDZ VOR. WE PASSED SLIGHTLY BEHIND AND BELOW THE SMA. TCAS INDICATED WE WERE 400' BELOW THE ACFT AS IT PASSED OVERHEAD. WE ADVISED ATC THAT WE HAD TAKEN EVASIVE ACTION DSNDING 400' BELOW OUR ASSIGNED ALT. ATC DID NOT ADVISE US OF THIS CONFLICT. THERE WERE A LARGE NUMBER OF ACFT IN THE VICINITY. OUR TCAS ON A TEN MI RANGE DISPLAYED 5 ADDITIONAL ACFT AT THE TIME OF THE INCIDENT. I'M SURE THE CTLR'S RADAR SCREEN WAS A WASH WITH TFC. THE TCAS WORKED WONDERFULLY; ALTHOUGH THE AUDIO WAS A BIT TOO LOUD (LOUD ENOUGH TO ALARM THE PAXS IN FIRST CLASS!). I WAS GLAD THE SYS WAS OPERATIONAL. TCAS NOT ONLY POINTED OUT THE CONFLICT FASTER THAN VIS ACQUISITION, BUT ALSO MADE OUR EVASIVE ACTIONS SMOOTHER AND MORE TEMPERED AS TO NOT CREATING ADDITIONAL CONFLICTS WITH OTHER ACFT IN THE SAME AIRSPACE.

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.