Narrative:

The incident occurred during 66 mi northeast of bld VOR at 330. We were on lax center frequency 126.35 and could hear conversations between lax and other aircraft. Due to thunderstorms in the area, we had our WX radar on and also had our TCAS system on. At this point I spotted an aircraft on TCAS at 12 O'clock 35-38 mi at our altitude. This aircraft continued inbound at our 12 O'clock and remained level our altitude. At 30 mi out it is common occurrence to see traffic at your level. Then they either climb or descend or turn. This target did not. At 20 mi out still at 12 O'clock I called lax center on 126.35 and asked about this target aircraft. My first call was blocked by another aircraft. On the second attempt lax said I was on the wrong frequency and to go to 124.2. We then got a TA of traffic from TCAS. I went outside and spotted the target aircraft at 12 O'clock our altitude. Approximately 8 mi out the first officer called lax on 124.2 and asked what this traffic was doing. TCAS then went RA, climb, climb. Since we were in visual conditions we started a turn 30-40 degree to left of course, as soon as TCAS saw the distance open up. It went to a monitor vertical speed warning. We later determined that the target aircraft had started a slow descent at approximately 5 mi out. TCAS works! Target aircraft passed 500-800 ft below us and 1.8-2.5 mi on our right side. Had we not turned it would have been very close. We elected to turn in order to stay within the confines of our airway rather than climb into someone else's airspace. ATC on 124.2 then handed us over to slc. Lax was anxious to hand us off. I believe the incident occurred due to ATC at lax combining sectors, at night and not having the combined sectors on 1 frequency. The controller on 126.85 was worried more about the frequency change to 124.2 than the traffic closing on my aircraft. Both lax controllers on 124.2 and 126.35 were more interested in cya than explaining what happened.

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Original NASA ASRS Text

Title: ACR TAKES EVASIVE ACTION FROM ACFT SAME ALT.

Narrative: THE INCIDENT OCCURRED DURING 66 MI NE OF BLD VOR AT 330. WE WERE ON LAX CENTER FREQ 126.35 AND COULD HEAR CONVERSATIONS BTWN LAX AND OTHER ACFT. DUE TO TSTMS IN THE AREA, WE HAD OUR WX RADAR ON AND ALSO HAD OUR TCAS SYS ON. AT THIS POINT I SPOTTED AN ACFT ON TCAS AT 12 O'CLOCK 35-38 MI AT OUR ALT. THIS ACFT CONTINUED INBOUND AT OUR 12 O'CLOCK AND REMAINED LEVEL OUR ALT. AT 30 MI OUT IT IS COMMON OCCURRENCE TO SEE TFC AT YOUR LEVEL. THEN THEY EITHER CLB OR DSND OR TURN. THIS TARGET DID NOT. AT 20 MI OUT STILL AT 12 O'CLOCK I CALLED LAX CENTER ON 126.35 AND ASKED ABOUT THIS TARGET ACFT. MY FIRST CALL WAS BLOCKED BY ANOTHER ACFT. ON THE SECOND ATTEMPT LAX SAID I WAS ON THE WRONG FREQ AND TO GO TO 124.2. WE THEN GOT A TA OF TFC FROM TCAS. I WENT OUTSIDE AND SPOTTED THE TARGET ACFT AT 12 O'CLOCK OUR ALT. APPROX 8 MI OUT THE FO CALLED LAX ON 124.2 AND ASKED WHAT THIS TFC WAS DOING. TCAS THEN WENT RA, CLB, CLB. SINCE WE WERE IN VISUAL CONDITIONS WE STARTED A TURN 30-40 DEG TO L OF COURSE, AS SOON AS TCAS SAW THE DISTANCE OPEN UP. IT WENT TO A MONITOR VERTICAL SPD WARNING. WE LATER DETERMINED THAT THE TARGET ACFT HAD STARTED A SLOW DSCNT AT APPROX 5 MI OUT. TCAS WORKS! TARGET ACFT PASSED 500-800 FT BELOW US AND 1.8-2.5 MI ON OUR R SIDE. HAD WE NOT TURNED IT WOULD HAVE BEEN VERY CLOSE. WE ELECTED TO TURN IN ORDER TO STAY WITHIN THE CONFINES OF OUR AIRWAY RATHER THAN CLB INTO SOMEONE ELSE'S AIRSPACE. ATC ON 124.2 THEN HANDED US OVER TO SLC. LAX WAS ANXIOUS TO HAND US OFF. I BELIEVE THE INCIDENT OCCURRED DUE TO ATC AT LAX COMBINING SECTORS, AT NIGHT AND NOT HAVING THE COMBINED SECTORS ON 1 FREQ. THE CTLR ON 126.85 WAS WORRIED MORE ABOUT THE FREQ CHANGE TO 124.2 THAN THE TFC CLOSING ON MY ACFT. BOTH LAX CTLRS ON 124.2 AND 126.35 WERE MORE INTERESTED IN CYA THAN EXPLAINING WHAT HAPPENED.

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.