Narrative:

Medium large transport X was descending into cmh and was turned to a 080 degree heading to avoid climbing aircraft off cmh. Was turned into path of medium large transport Y also descending into cmh at much slower rate. Medium large transport X was given a clearance to amend altitude above that of medium large transport Y, but clearance was not issued in time and medium large transport X went through the altitude and had to climb back up.

Google
 

Original NASA ASRS Text

Title: ARTCC CTLR LATE WITH AMENDED ALT ASSIGNMENT FOR MLG X AND ACFT OVERSHOT ALT ASSIGNMENT AND HAD LESS THAN STANDARD SEPARATION WITH ANOTHER MLG DESCENDING.

Narrative: MLG X WAS DESCENDING INTO CMH AND WAS TURNED TO A 080 DEG HDG TO AVOID CLIMBING ACFT OFF CMH. WAS TURNED INTO PATH OF MLG Y ALSO DESCENDING INTO CMH AT MUCH SLOWER RATE. MLG X WAS GIVEN A CLRNC TO AMEND ALT ABOVE THAT OF MLG Y, BUT CLRNC WAS NOT ISSUED IN TIME AND MLG X WENT THROUGH THE ALT AND HAD TO CLIMB BACK UP.

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.