Narrative:

Air carrier X was on a vector to the west for spacing to ord. Air carrier Y was northeast bound on J29. Although I did not initially recognize the 2 aircraft as a potential conflict, the vector took air carrier X behind air carrier Y. When spacing was accomplished I cleared air carrier X on course. Shortly thereafter I recognized the problem but initially judged that air carrier X would still go behind air carrier Y but when air carrier X turned he picked up speed and 'caught' the crw on the backside. When I saw it was not going to clear, I turned air carrier Y and descended air carrier X too late. In short, I screwed up! Supplemental information from acn 125542: conflict alert flashed with air carrier Y. The radar person immediately told air carrier X to descend to FL350 and he acknowledged. The radar controller then told air carrier Y to turn 30 degree left several times, but he didn't reply.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN ACR X AND Y. SYSTEM ERROR.

Narrative: ACR X WAS ON A VECTOR TO THE W FOR SPACING TO ORD. ACR Y WAS NE BOUND ON J29. ALTHOUGH I DID NOT INITIALLY RECOGNIZE THE 2 ACFT AS A POTENTIAL CONFLICT, THE VECTOR TOOK ACR X BEHIND ACR Y. WHEN SPACING WAS ACCOMPLISHED I CLRED ACR X ON COURSE. SHORTLY THEREAFTER I RECOGNIZED THE PROBLEM BUT INITIALLY JUDGED THAT ACR X WOULD STILL GO BEHIND ACR Y BUT WHEN ACR X TURNED HE PICKED UP SPEED AND 'CAUGHT' THE CRW ON THE BACKSIDE. WHEN I SAW IT WAS NOT GOING TO CLEAR, I TURNED ACR Y AND DESCENDED ACR X TOO LATE. IN SHORT, I SCREWED UP! SUPPLEMENTAL INFORMATION FROM ACN 125542: CONFLICT ALERT FLASHED WITH ACR Y. THE RADAR PERSON IMMEDIATELY TOLD ACR X TO DSND TO FL350 AND HE ACKNOWLEDGED. THE RADAR CTLR THEN TOLD ACR Y TO TURN 30 DEG LEFT SEVERAL TIMES, BUT HE DIDN'T REPLY.

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.