Narrative:

Medium large transport X en route climb to fsd via direct lmn climbing to FL310. Large transport Y en route climb to ord via mkc 075 degree right J105 bdf climbing to FL330. Large transport X was then stopped at FL290 erroneously intended to be stopped at FL280. The manual or d-side trner observed that FL290 was erroneous and large transport Y was then instructed to maintain FL280. Large transport Y reported leaving FL280 for FL280 and xa:46.18. Medium large transport X reported out of FL297 at xa:46.45. Sep lost at xa:46.30, 700' sep.

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Original NASA ASRS Text

Title: ARTCC CTLR INADVERTENTLY CLIMBED AN LGT TO THE WRONG ALT, CAUSED LESS THAN STANDARD SEPARATION WITH AN MLG.

Narrative: MLG X ENRTE CLB TO FSD VIA DIRECT LMN CLBING TO FL310. LGT Y ENRTE CLB TO ORD VIA MKC 075 DEG R J105 BDF CLBING TO FL330. LGT X WAS THEN STOPPED AT FL290 ERRONEOUSLY INTENDED TO BE STOPPED AT FL280. THE MANUAL OR D-SIDE TRNER OBSERVED THAT FL290 WAS ERRONEOUS AND LGT Y WAS THEN INSTRUCTED TO MAINTAIN FL280. LGT Y RPTED LEAVING FL280 FOR FL280 AND XA:46.18. MLG X RPTED OUT OF FL297 AT XA:46.45. SEP LOST AT XA:46.30, 700' SEP.

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.