Narrative:

Air carrier X northbound direct djb at FL200. Air carrier X switched to mfd low. Ape high radar controller asked for lower on cga Y. I gave him FL210. Cga Y called on descending to FL210. I assigned him present heading (V050) for air carrier X traffic and I also descended him to 15000 ft. I monitored the situation and turned cga Y to heading of 090 degrees. When I realized heading of 090 degrees was not sufficient, I turned cga Y to heading of 120 degrees. Aedp activated. Reason for error: poor judgement on my (controller's) part. The aircraft did not turn as quickly as I thought. Vector would have worked if turn was issued at call on of cga Y. Overall, should have kept aircraft XXX at FL210 until turn was completed, ensuring 5 NM separation. I apologize for my use of poor judgement. This has been a humbling but motivational experience so as to improve my skills and to provide better service to the flying public. Please feel free to phone me with any questions.

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Original NASA ASRS Text

Title: A CTR RADAR CTLR DSNDED AN LR55 THROUGH THE ALT OF A SAME DIRECTION SF34 LEVEL AT FL200. DUE TO SPD DIFFERENCE, THE LR55 OVERTOOK THE SF34 AND HDGS TO MAINTAIN SEPARATION WERE NOT SUFFICIENT TO PREVENT A LOSS OF SEPARATION.

Narrative: ACR X NBOUND DIRECT DJB AT FL200. ACR X SWITCHED TO MFD LOW. APE HIGH RADAR CTLR ASKED FOR LOWER ON CGA Y. I GAVE HIM FL210. CGA Y CALLED ON DSNDING TO FL210. I ASSIGNED HIM PRESENT HDG (V050) FOR ACR X TFC AND I ALSO DSNDED HIM TO 15000 FT. I MONITORED THE SIT AND TURNED CGA Y TO HDG OF 090 DEGS. WHEN I REALIZED HDG OF 090 DEGS WAS NOT SUFFICIENT, I TURNED CGA Y TO HDG OF 120 DEGS. AEDP ACTIVATED. REASON FOR ERROR: POOR JUDGEMENT ON MY (CTLR'S) PART. THE ACFT DID NOT TURN AS QUICKLY AS I THOUGHT. VECTOR WOULD HAVE WORKED IF TURN WAS ISSUED AT CALL ON OF CGA Y. OVERALL, SHOULD HAVE KEPT ACFT XXX AT FL210 UNTIL TURN WAS COMPLETED, ENSURING 5 NM SEPARATION. I APOLOGIZE FOR MY USE OF POOR JUDGEMENT. THIS HAS BEEN A HUMBLING BUT MOTIVATIONAL EXPERIENCE SO AS TO IMPROVE MY SKILLS AND TO PROVIDE BETTER SVC TO THE FLYING PUBLIC. PLEASE FEEL FREE TO PHONE ME WITH ANY QUESTIONS.

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.