Narrative:

An aircraft X was climbing to 5000 ft and another aircraft Y (C550) was on a vector at 3000 ft. I saw both aircraft at 3000 ft and told the aircraft that was climbing (aircraft X) to expedite and I issued a turn. I tried to descend the aircraft that was at 3000 ft (aircraft Y), but the aircraft hadn't been switched to my frequency.

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Original NASA ASRS Text

Title: PHL APCH CTLR INCORRECTLY JUDGES CLBING GIV SEPARATION FROM AN ENRTE BE40.

Narrative: AN ACFT X WAS CLBING TO 5000 FT AND ANOTHER ACFT Y (C550) WAS ON A VECTOR AT 3000 FT. I SAW BOTH ACFT AT 3000 FT AND TOLD THE ACFT THAT WAS CLBING (ACFT X) TO EXPEDITE AND I ISSUED A TURN. I TRIED TO DSND THE ACFT THAT WAS AT 3000 FT (ACFT Y), BUT THE ACFT HADN'T BEEN SWITCHED TO MY FREQ.

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.