Narrative:

Descending air carrier X into tri with crossing restriction at or below 12000' in 1 1/2 mins. Climbing air carrier Y with restriction at or above 13000' in 1 1/2 mins. Air carrier Y misread clearance. I reissued clearance to air carrier Y at or above 13000' in about 1 min. Phraseology error and too late at this point to get sep. Discovered by C/a. I was decertified, pending investigation. No evasive action required. Poor communication between controller and air carrier Y contributed to error. Need more timely clearance and better listening by pilots to avoid this type of error. Poor timing on my part.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN ACR X AND Y. SYSTEM ERROR.

Narrative: DSNDING ACR X INTO TRI WITH XING RESTRICTION AT OR BELOW 12000' IN 1 1/2 MINS. CLBING ACR Y WITH RESTRICTION AT OR ABOVE 13000' IN 1 1/2 MINS. ACR Y MISREAD CLRNC. I REISSUED CLRNC TO ACR Y AT OR ABOVE 13000' IN ABOUT 1 MIN. PHRASEOLOGY ERROR AND TOO LATE AT THIS POINT TO GET SEP. DISCOVERED BY C/A. I WAS DECERTIFIED, PENDING INVESTIGATION. NO EVASIVE ACTION REQUIRED. POOR COM BTWN CTLR AND ACR Y CONTRIBUTED TO ERROR. NEED MORE TIMELY CLRNC AND BETTER LISTENING BY PLTS TO AVOID THIS TYPE OF ERROR. POOR TIMING ON MY PART.

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.