Narrative:

We entered the WX descending into lax at about 3500' and were cleared to descend to 2500' and were also cleared for an ILS approach to 24R at lax. After being established at 2500' and tracking the localizer, a light aircraft crossed our path heading southeast at our altitude and somewhere between 30-100' in front. Our DME read 14.5 mi and it was too late to take evasive action. We immediately reported a near miss to approach control and they requested that we call them on the ground. The light aircraft was a single engine, low wing, white with blue stripes and I think it was a tail. When I called TRACON, I talked to the supervisor and he explained that the parallel monitoring radar had picked up a primary target but they hadn't yet picked us up, because that radar has such a narrow range.

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Original NASA ASRS Text

Title: NMAC BETWEEN IFR LGT ON APCH IN IMC AND UNIDENTIFIED SMA VFR IN IMC. UNABLE CALLBACK.

Narrative: WE ENTERED THE WX DESCENDING INTO LAX AT ABOUT 3500' AND WERE CLRED TO DSND TO 2500' AND WERE ALSO CLRED FOR AN ILS APCH TO 24R AT LAX. AFTER BEING ESTABLISHED AT 2500' AND TRACKING THE LOC, A LIGHT ACFT CROSSED OUR PATH HDG SE AT OUR ALT AND SOMEWHERE BETWEEN 30-100' IN FRONT. OUR DME READ 14.5 MI AND IT WAS TOO LATE TO TAKE EVASIVE ACTION. WE IMMEDIATELY REPORTED A NEAR MISS TO APCH CTL AND THEY REQUESTED THAT WE CALL THEM ON THE GND. THE LIGHT ACFT WAS A SINGLE ENGINE, LOW WING, WHITE WITH BLUE STRIPES AND I THINK IT WAS A TAIL. WHEN I CALLED TRACON, I TALKED TO THE SUPVR AND HE EXPLAINED THAT THE PARALLEL MONITORING RADAR HAD PICKED UP A PRIMARY TARGET BUT THEY HADN'T YET PICKED US UP, BECAUSE THAT RADAR HAS SUCH A NARROW RANGE.

Data retrieved from NASA's ASRS site as of August 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.