Narrative:

Immediately after contacting departure control at lax I was given traffic at 12 O'clock (large transport on the loop departure). When I called him in sight I was cleared visual separation to 13000 ft. After this I was then given a vector of 160 degrees from my current heading of 210 degrees. As the first officer was flying the aircraft and we were now in a left bank to the new heading, I lost sight of the traffic which had now started its left turn back to the lax VOR. We did not regain visual on the aircraft until the first officer was rolling the wings level at the conclusion of the turn. At this time the aircraft was at our 10 O'clock position and about 500 ft below us moving from right to left. A right turn was initiated to give a little more space and I advised departure control of this. After the large transport was clear of us, I asked departure how close the aircraft had come to us. After he said that the 2 targets had merged on his radar he proceeded to read me the riot act over the radio. Had I not been turned when I was, I would probably not have lost contact with the traffic and put in that position. Add to this the fact that depth perception over a dark ocean at night is virtually nil and this could have turned into something nasty.

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Original NASA ASRS Text

Title: LGT HAS NMAC WITH SECOND LGT ON CLBOUT.

Narrative: IMMEDIATELY AFTER CONTACTING DEP CTL AT LAX I WAS GIVEN TFC AT 12 O'CLOCK (LGT ON THE LOOP DEP). WHEN I CALLED HIM IN SIGHT I WAS CLRED VISUAL SEPARATION TO 13000 FT. AFTER THIS I WAS THEN GIVEN A VECTOR OF 160 DEGS FROM MY CURRENT HDG OF 210 DEGS. AS THE FO WAS FLYING THE ACFT AND WE WERE NOW IN A L BANK TO THE NEW HDG, I LOST SIGHT OF THE TFC WHICH HAD NOW STARTED ITS L TURN BACK TO THE LAX VOR. WE DID NOT REGAIN VISUAL ON THE ACFT UNTIL THE FO WAS ROLLING THE WINGS LEVEL AT THE CONCLUSION OF THE TURN. AT THIS TIME THE ACFT WAS AT OUR 10 O'CLOCK POS AND ABOUT 500 FT BELOW US MOVING FROM R TO L. A R TURN WAS INITIATED TO GIVE A LITTLE MORE SPACE AND I ADVISED DEP CTL OF THIS. AFTER THE LGT WAS CLR OF US, I ASKED DEP HOW CLOSE THE ACFT HAD COME TO US. AFTER HE SAID THAT THE 2 TARGETS HAD MERGED ON HIS RADAR HE PROCEEDED TO READ ME THE RIOT ACT OVER THE RADIO. HAD I NOT BEEN TURNED WHEN I WAS, I WOULD PROBABLY NOT HAVE LOST CONTACT WITH THE TFC AND PUT IN THAT POS. ADD TO THIS THE FACT THAT DEPTH PERCEPTION OVER A DARK OCEAN AT NIGHT IS VIRTUALLY NIL AND THIS COULD HAVE TURNED INTO SOMETHING NASTY.

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.