Narrative:

Air carrier X departed slc runway 16R at XX41:40Z, issued heading 300 degree altitude 16,000. Filed route J173 eastbound. At XX44:20 air carrier Y departed for 16R, issued heading 300 degree, altitude 16,000. Air carrier X was very heavy, slow climber, air carrier Y was light and a fast climber. At XX44:46 air carrier X was issued turn right heading 100 degree. Air carrier X made wide turn and crossed projected path of air carrier Y with separation of 2.3 NM and 600' above air carrier Y. As they were crossing I told air carrier Y 'traffic 12 O'clock 2 mi eastbound about 1000' above you'. Air carrier Y requested his altitude and I told him he was now 1300' above and eastbound, and that I'm turning behind him nebnd. Pilot said nothing more. 12 days later company calls facility to inquire about incident. Tapes revealed nothing conclusive, ARTS plot revealed operational error! Supplemental information from acn 124899: after accelerating to 300 KIAS I resumed a 4000 FPM climb. At 11,400' I determined that an large transport which we had been monitoring was in fact closing with us. He appeared to be on a heading of 100 degree, moving slightly left to right across our nose at about 12,000'. I pushed over and descended to 11,300. They passed slightly to our right and about 600' above us. We spotted them at a distance of about 3 mi.

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Original NASA ASRS Text

Title: ACR STOPPED CLIMB DUE TO CLOSE PROX OF TRAFFIC.

Narrative: ACR X DEPARTED SLC RWY 16R AT XX41:40Z, ISSUED HDG 300 DEG ALT 16,000. FILED ROUTE J173 EBND. AT XX44:20 ACR Y DEPARTED FOR 16R, ISSUED HDG 300 DEG, ALT 16,000. ACR X WAS VERY HEAVY, SLOW CLIMBER, ACR Y WAS LIGHT AND A FAST CLIMBER. AT XX44:46 ACR X WAS ISSUED TURN RIGHT HDG 100 DEG. ACR X MADE WIDE TURN AND CROSSED PROJECTED PATH OF ACR Y WITH SEPARATION OF 2.3 NM AND 600' ABOVE ACR Y. AS THEY WERE XING I TOLD ACR Y 'TFC 12 O'CLOCK 2 MI EBND ABOUT 1000' ABOVE YOU'. ACR Y REQUESTED HIS ALT AND I TOLD HIM HE WAS NOW 1300' ABOVE AND EBND, AND THAT I'M TURNING BEHIND HIM NEBND. PLT SAID NOTHING MORE. 12 DAYS LATER COMPANY CALLS FAC TO INQUIRE ABOUT INCIDENT. TAPES REVEALED NOTHING CONCLUSIVE, ARTS PLOT REVEALED OPERATIONAL ERROR! SUPPLEMENTAL INFORMATION FROM ACN 124899: AFTER ACCELERATING TO 300 KIAS I RESUMED A 4000 FPM CLIMB. AT 11,400' I DETERMINED THAT AN LGT WHICH WE HAD BEEN MONITORING WAS IN FACT CLOSING WITH US. HE APPEARED TO BE ON A HDG OF 100 DEG, MOVING SLIGHTLY LEFT TO RIGHT ACROSS OUR NOSE AT ABOUT 12,000'. I PUSHED OVER AND DESCENDED TO 11,300. THEY PASSED SLIGHTLY TO OUR RIGHT AND ABOUT 600' ABOVE US. WE SPOTTED THEM AT A DISTANCE OF ABOUT 3 MI.

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.