Narrative:

Aircraft #2 descending from FL250 to FL240. Aircraft #1 descending to FL260 20 mi away opposite direction meant to issue FL240 to aircraft #1 but inadvertently issued it to another similar call sign.

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Original NASA ASRS Text

Title: ZID CTLR EXPERIENCED OPERROR WHEN DSCNT CLRNC WAS ISSUED TO WRONG ACFT WITH SIMILAR, SAME COMPANY, FLT NUMBER.

Narrative: ACFT #2 DSNDING FROM FL250 TO FL240. ACFT #1 DSNDING TO FL260 20 MI AWAY OPPOSITE DIRECTION MEANT TO ISSUE FL240 TO ACFT #1 BUT INADVERTENTLY ISSUED IT TO ANOTHER SIMILAR CALL SIGN.

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.