Narrative:

Air carrier light transport X departed runway 19L at iad and was turned to 220 degrees by the tower. The tower had indicated 220 degrees on the flight strip and circled it meaning do not turn the aircraft until at least 5 mi out. It was a busy departure period. I switched another air carrier light transport to another sector and mistakenly filed air carrier light transport X flight strip. I then turned light transport X to a 360 degree heading. The aircraft was climbing from about 2500 to 7000 ft. An medium large transport Y departed runway 19L on a 240 degree heading and checked in to my frequency level at 4000 ft. At this time the aircraft were at closest proximity. Had the medium large transport Y checked in sooner I could have leveled him at 3000 ft. Due to frequency congestion and other duties I did not hear medium large transport Y call until it was too late to take action. Airspace constraints contribute to this type of incident because we can not climb and turn departures expeditiously. Overflts and arrival traffic must be 'missed' before departures can climb. Difference in performance between the light transport X and the medium large transport Y also was a factor.

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Original NASA ASRS Text

Title: DEP CTLR TURNED LTT TOO SOON AFTER TKOF AND CAUSED LTSS WITH AN MLG DEP OFF PARALLEL RWY.

Narrative: ACR LTT X DEPARTED RWY 19L AT IAD AND WAS TURNED TO 220 DEGS BY THE TWR. THE TWR HAD INDICATED 220 DEGS ON THE FLT STRIP AND CIRCLED IT MEANING DO NOT TURN THE ACFT UNTIL AT LEAST 5 MI OUT. IT WAS A BUSY DEP PERIOD. I SWITCHED ANOTHER ACR LTT TO ANOTHER SECTOR AND MISTAKENLY FILED ACR LTT X FLT STRIP. I THEN TURNED LTT X TO A 360 DEG HDG. THE ACFT WAS CLBING FROM ABOUT 2500 TO 7000 FT. AN MLG Y DEPARTED RWY 19L ON A 240 DEG HDG AND CHKED IN TO MY FREQ LEVEL AT 4000 FT. AT THIS TIME THE ACFT WERE AT CLOSEST PROX. HAD THE MLG Y CHKED IN SOONER I COULD HAVE LEVELED HIM AT 3000 FT. DUE TO FREQ CONGESTION AND OTHER DUTIES I DID NOT HEAR MLG Y CALL UNTIL IT WAS TOO LATE TO TAKE ACTION. AIRSPACE CONSTRAINTS CONTRIBUTE TO THIS TYPE OF INCIDENT BECAUSE WE CAN NOT CLB AND TURN DEPS EXPEDITIOUSLY. OVERFLTS AND ARR TFC MUST BE 'MISSED' BEFORE DEPS CAN CLB. DIFFERENCE IN PERFORMANCE BTWN THE LTT X AND THE MLG Y ALSO WAS A FACTOR.

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.