Narrative:

Air carrier X, sbound, contacted radar controller climbing to FL270. Air carrier Y, eastbound, level at FL290. Controller, on initial contact, climbed X to FL310. Controller was aware of the situation but determined X would climb above Y prior to losing lateral separation. When controller realized climb rate was not sufficient to achieve vertical separation, controller turned both aircraft degree degrees right. Lateral and vertical separation was lost. Supplemental information from acn 265844: initially when I climbed aircraft X to FL310 I thought the rate of climb would be enough so that he would be level so that aircraft Y would not be a problem. (When I issued the climb aircraft X was 50 mi north of ape at FL230 and aircraft Y was 50 mi west of ape much slower.) conflict alert activated when both aircraft were about 10 mi apart. I turned aircraft X 30 degrees to the right and aircraft Y 40 degrees to the right. Aircraft X passed 3.5 mi behind aircraft Y.

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Original NASA ASRS Text

Title: ACR X CLB THROUGH OCCUPIED ALT HAD LTSS FROM ACR Y. SYS ERROR.

Narrative: ACR X, SBOUND, CONTACTED RADAR CTLR CLBING TO FL270. ACR Y, EBOUND, LEVEL AT FL290. CTLR, ON INITIAL CONTACT, CLBED X TO FL310. CTLR WAS AWARE OF THE SIT BUT DETERMINED X WOULD CLB ABOVE Y PRIOR TO LOSING LATERAL SEPARATION. WHEN CTLR REALIZED CLB RATE WAS NOT SUFFICIENT TO ACHIEVE VERT SEPARATION, CTLR TURNED BOTH ACFT DEG DEGS R. LATERAL AND VERT SEPARATION WAS LOST. SUPPLEMENTAL INFORMATION FROM ACN 265844: INITIALLY WHEN I CLBED ACFT X TO FL310 I THOUGHT THE RATE OF CLB WOULD BE ENOUGH SO THAT HE WOULD BE LEVEL SO THAT ACFT Y WOULD NOT BE A PROB. (WHEN I ISSUED THE CLB ACFT X WAS 50 MI N OF APE AT FL230 AND ACFT Y WAS 50 MI W OF APE MUCH SLOWER.) CONFLICT ALERT ACTIVATED WHEN BOTH ACFT WERE ABOUT 10 MI APART. I TURNED ACFT X 30 DEGS TO THE R AND ACFT Y 40 DEGS TO THE R. ACFT X PASSED 3.5 MI BEHIND ACFT Y.

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.