Narrative:

Descending into ont, ca, traffic appeared on our vsi/tra indicator approximately 3 mi to our right and 300 ft below our altitude (10000 ft). Socal approach cleared us to maintain 8000 ft and descent was initiated. Approach also gave us a vector to 180 degrees which turned us slightly away from the TCASII target. Passing approximately 9800 ft we received a climb RA (commanding 1500-2000 ft climb) and previous traffic appeared on vsi/tra indicator inside 2 NM range ring to our right at 200 ft below our altitude. We began climb and advised socal controller of climb and requirement to comply with RA. We never saw the traffic although the visibility was about 3 mi. The controller stated he was talking to 'both aircraft' but we were never advised of traffic other than just prior to this conflict the controller stated there was traffic over big bear that had us in sight (we think the controller probably mistakenly said big bear since that area was behind us). Following compliance with TCASII descended normally for approach/landing. Supplemental information from acn 347835: maximum altitude reached in climb was approximately 10400 ft.

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Original NASA ASRS Text

Title: ACR DSNDING INTO ONT NEAR GARY INTXN DSNDING TO 8000 FT HAD TCASII TO TARGET 300 FT BELOW. LEAVING 9800 FT GOT RA TO CLB AND COMPLIED REACHING 10400 FT. CTLR ADVISED WAS IN COM WITH BOTH ACFT BUT FAILED TO ADVISE OF TFC.

Narrative: DSNDING INTO ONT, CA, TFC APPEARED ON OUR VSI/TRA INDICATOR APPROX 3 MI TO OUR R AND 300 FT BELOW OUR ALT (10000 FT). SOCAL APCH CLRED US TO MAINTAIN 8000 FT AND DSCNT WAS INITIATED. APCH ALSO GAVE US A VECTOR TO 180 DEGS WHICH TURNED US SLIGHTLY AWAY FROM THE TCASII TARGET. PASSING APPROX 9800 FT WE RECEIVED A CLB RA (COMMANDING 1500-2000 FT CLB) AND PREVIOUS TFC APPEARED ON VSI/TRA INDICATOR INSIDE 2 NM RANGE RING TO OUR R AT 200 FT BELOW OUR ALT. WE BEGAN CLB AND ADVISED SOCAL CTLR OF CLB AND REQUIREMENT TO COMPLY WITH RA. WE NEVER SAW THE TFC ALTHOUGH THE VISIBILITY WAS ABOUT 3 MI. THE CTLR STATED HE WAS TALKING TO 'BOTH ACFT' BUT WE WERE NEVER ADVISED OF TFC OTHER THAN JUST PRIOR TO THIS CONFLICT THE CTLR STATED THERE WAS TFC OVER BIG BEAR THAT HAD US IN SIGHT (WE THINK THE CTLR PROBABLY MISTAKENLY SAID BIG BEAR SINCE THAT AREA WAS BEHIND US). FOLLOWING COMPLIANCE WITH TCASII DSNDED NORMALLY FOR APCH/LNDG. SUPPLEMENTAL INFO FROM ACN 347835: MAX ALT REACHED IN CLB WAS APPROX 10400 FT.

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.