Narrative:

Lax center turned us over to ont approach who was also extremely busy as we were given more vectors and cleared to 6000'. Approximately 20 mi northeast of ont we were descending with speed brakes extended when out of my peripheral vision I saw an aircraft approaching at approximately 2 O'clock on an easterly heading at our altitude. I quickly determined that we were on a collision course and made an immediate left turn as I pointed out the traffic to the first officer who was busy entering new clearance data into the flight management computer. The other aircraft was a single engine small aircraft that we missed by approximately 1000' horizontally with no vertical sep. We estimated that if we had not turned, collision would have occurred in 3-5 seconds. We tried to tell ont approach about the 'near miss' but he was too busy to respond. We did later hear approach point out this traffic to aircraft behind us, so he was aware of the traffic he just didn't advise us of the conflict. I called the shift supervisor for ont approach when on the ground and he said 'he was expecting my call.' he said lax center was 'down the tubes' and ont approach was affected by that also. He also stated that our approach controller was a trnee and that the trainer thought the trnee had pointed out the small aircraft to us, which he later found out was not the case. The supervisor then turned me over to the area manager with whom I filed a 'near midair collision' report.

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Original NASA ASRS Text

Title: MLG ACR IN DESCENT TO ONT PER CLRNC BY ONT TRACON OBSERVED AN SMA ON COLLISION COURSE AT APPROX 8000' MSL. TOOK EVASIVE ACTION TO AVOID MISSING BY 1000' HORIZONTAL 0 VERTICAL.

Narrative: LAX CTR TURNED US OVER TO ONT APCH WHO WAS ALSO EXTREMELY BUSY AS WE WERE GIVEN MORE VECTORS AND CLRED TO 6000'. APPROX 20 MI NE OF ONT WE WERE DSNDING WITH SPD BRAKES EXTENDED WHEN OUT OF MY PERIPHERAL VISION I SAW AN ACFT APCHING AT APPROX 2 O'CLOCK ON AN EASTERLY HDG AT OUR ALT. I QUICKLY DETERMINED THAT WE WERE ON A COLLISION COURSE AND MADE AN IMMEDIATE L TURN AS I POINTED OUT THE TFC TO THE F/O WHO WAS BUSY ENTERING NEW CLRNC DATA INTO THE FLT MGMNT COMPUTER. THE OTHER ACFT WAS A SINGLE ENG SMA THAT WE MISSED BY APPROX 1000' HORIZLY WITH NO VERT SEP. WE ESTIMATED THAT IF WE HAD NOT TURNED, COLLISION WOULD HAVE OCCURRED IN 3-5 SECS. WE TRIED TO TELL ONT APCH ABOUT THE 'NEAR MISS' BUT HE WAS TOO BUSY TO RESPOND. WE DID LATER HEAR APCH POINT OUT THIS TFC TO ACFT BEHIND US, SO HE WAS AWARE OF THE TFC HE JUST DIDN'T ADVISE US OF THE CONFLICT. I CALLED THE SHIFT SUPVR FOR ONT APCH WHEN ON THE GND AND HE SAID 'HE WAS EXPECTING MY CALL.' HE SAID LAX CTR WAS 'DOWN THE TUBES' AND ONT APCH WAS AFFECTED BY THAT ALSO. HE ALSO STATED THAT OUR APCH CTLR WAS A TRNEE AND THAT THE TRAINER THOUGHT THE TRNEE HAD POINTED OUT THE SMA TO US, WHICH HE LATER FOUND OUT WAS NOT THE CASE. THE SUPVR THEN TURNED ME OVER TO THE AREA MGR WITH WHOM I FILED A 'NMAC' RPT.

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.