Narrative:

I was working departure in a north flow. Aircraft X departed dallas, love field and I climbed the aircraft to 6000 ft. About the same time, aircraft Y departed dfw airport climbing to 10000 ft. At 6 mi north of dfw, I turned aircraft Y to a heading of 090 degrees. 5 mi northwest of dallas love, aircraft X turned to heading of 360 degrees as per the departure procedures. I observed aircraft Y slow climbing out of 5000 ft and told the pilot to expedite his climb to 10000 ft. Then I realized that aircraft Y would not be 1000 ft above aircraft X at the point where I would lose 3 mi. I tried to keep the planes from an unsafe situation by turning aircraft X to heading of 100 degrees and expediting his climb to 10000 ft. At the same time, I told aircraft Y to stop his climb. My hope, at this point, was to get the aircraft on parallel headings and get the faster climber above the slower climber. These measures also would allow the pilots to see each other. I lost separation and then the pilots saw each other.

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Original NASA ASRS Text

Title: DFW DEP CTLR'S CTL ACTIONS INSUFFICIENT TO MAINTAIN LEGAL SEPARATION BTWN A DEPARTING DAL JET FROM A DEPARTING DFW ACR.

Narrative: I WAS WORKING DEP IN A N FLOW. ACFT X DEPARTED DALLAS, LOVE FIELD AND I CLBED THE ACFT TO 6000 FT. ABOUT THE SAME TIME, ACFT Y DEPARTED DFW ARPT CLBING TO 10000 FT. AT 6 MI N OF DFW, I TURNED ACFT Y TO A HDG OF 090 DEGS. 5 MI NW OF DALLAS LOVE, ACFT X TURNED TO HDG OF 360 DEGS AS PER THE DEP PROCS. I OBSERVED ACFT Y SLOW CLBING OUT OF 5000 FT AND TOLD THE PLT TO EXPEDITE HIS CLB TO 10000 FT. THEN I REALIZED THAT ACFT Y WOULD NOT BE 1000 FT ABOVE ACFT X AT THE POINT WHERE I WOULD LOSE 3 MI. I TRIED TO KEEP THE PLANES FROM AN UNSAFE SIT BY TURNING ACFT X TO HDG OF 100 DEGS AND EXPEDITING HIS CLB TO 10000 FT. AT THE SAME TIME, I TOLD ACFT Y TO STOP HIS CLB. MY HOPE, AT THIS POINT, WAS TO GET THE ACFT ON PARALLEL HDGS AND GET THE FASTER CLIMBER ABOVE THE SLOWER CLIMBER. THESE MEASURES ALSO WOULD ALLOW THE PLTS TO SEE EACH OTHER. I LOST SEPARATION AND THEN THE PLTS SAW EACH OTHER.

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.