Narrative:

While working departure radar east, I instructed aircraft X to climb and maintain 11000 ft. Aircraft Y was southeast of mes level at 9000 ft nebound with no mode C (transponder signal was not being received by the radar, it was working normally prior to this incident). I mistakenly was thinking that aircraft Y was at 8000 ft and that I only needed aircraft X to be out of 9000 ft to avoid conflict. When I looked back at the position and altitude of the 2 aircraft, and aircraft X was out of 9000 ft, I then remembered that aircraft Y was at 9000 ft not 8000 ft. I then issued turns to get the aircraft on diverging courses, then instructed aircraft X to expedite the climb.

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Original NASA ASRS Text

Title: DEVELOPMENTAL MEM DEP CTLR HAS A MEMORY ERROR WHEN CLBING AN SF34, WHICH CONFLICTS WITH AN ENRTE DC3.

Narrative: WHILE WORKING DEP RADAR E, I INSTRUCTED ACFT X TO CLB AND MAINTAIN 11000 FT. ACFT Y WAS SE OF MES LEVEL AT 9000 FT NEBOUND WITH NO MODE C (XPONDER SIGNAL WAS NOT BEING RECEIVED BY THE RADAR, IT WAS WORKING NORMALLY PRIOR TO THIS INCIDENT). I MISTAKENLY WAS THINKING THAT ACFT Y WAS AT 8000 FT AND THAT I ONLY NEEDED ACFT X TO BE OUT OF 9000 FT TO AVOID CONFLICT. WHEN I LOOKED BACK AT THE POS AND ALT OF THE 2 ACFT, AND ACFT X WAS OUT OF 9000 FT, I THEN REMEMBERED THAT ACFT Y WAS AT 9000 FT NOT 8000 FT. I THEN ISSUED TURNS TO GET THE ACFT ON DIVERGING COURSES, THEN INSTRUCTED ACFT X TO EXPEDITE THE CLB.

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.