Narrative:

Air carrier X was issued descent to FL270, correction FL290, no delay to FL290. Air carrier X read back 'descend to FL220, no delay through FL290.' I missed the readback. Supplemental information from acn 636778: air carrier Y at FL280 switched to 133.42. Air carrier X descended to FL270. Correction FL290, no delay to FL290. Air carrier X read back FL270, no delay through FL290.

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Original NASA ASRS Text

Title: AN AMENDED CLRNC ISSUED BY A ZID ARTCC RADAR CTLR IS MISINTERPED BY AN ACR CREW RESULTING IN A LOSS OF SEPARATION. THE CTLR MISSED THE INCORRECT READBACK.

Narrative: ACR X WAS ISSUED DSCNT TO FL270, CORRECTION FL290, NO DELAY TO FL290. ACR X READ BACK 'DSND TO FL220, NO DELAY THROUGH FL290.' I MISSED THE READBACK. SUPPLEMENTAL INFO FROM ACN 636778: ACR Y AT FL280 SWITCHED TO 133.42. ACR X DSNDED TO FL270. CORRECTION FL290, NO DELAY TO FL290. ACR X READ BACK FL270, NO DELAY THROUGH FL290.

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.