Narrative:

Uga X departed loz climbing to 4000 ft, a BE35. Uga Y on frequency sbound V97 over loz at 5000 ft, a PA28. Uga Z northbound at 6000 ft was 15 mi south of loz arriving, a BE55. Having observed the departing uga X, I turned uga Z to a 300 degree heading and descended to 4000 ft, reaching 4000 ft cleared direct loz. Uga X was idented and turned to a 100 degree heading to clear the arrival path for uga Z. When uga Z turned direct to loz, I was unsure of maintaining 5 mi. I then checked distance between uga X and uga Y and determined I had 5.5 mi and increasing so I issued uga X a 090 degree heading and 6000 ft. When I observed that the eastbound heading was losing distance, I turned uga Y to a 270 degree heading but not soon enough to prevent a loss of separation. Callback conversation with reporter revealed the following information: reporter stated that the aircraft were on diverging courses. Reporter lost separation after turning lead aircraft perpendicular to the established course of the trailing aircraft which allowed the interval between aircraft to close to less than was required.

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Original NASA ASRS Text

Title: LTSS BTWN UGA X AND UGA Y. SYS ERROR.

Narrative: UGA X DEPARTED LOZ CLBING TO 4000 FT, A BE35. UGA Y ON FREQ SBOUND V97 OVER LOZ AT 5000 FT, A PA28. UGA Z NBOUND AT 6000 FT WAS 15 MI S OF LOZ ARRIVING, A BE55. HAVING OBSERVED THE DEPARTING UGA X, I TURNED UGA Z TO A 300 DEG HDG AND DSNDED TO 4000 FT, REACHING 4000 FT CLRED DIRECT LOZ. UGA X WAS IDENTED AND TURNED TO A 100 DEG HDG TO CLR THE ARR PATH FOR UGA Z. WHEN UGA Z TURNED DIRECT TO LOZ, I WAS UNSURE OF MAINTAINING 5 MI. I THEN CHKED DISTANCE BTWN UGA X AND UGA Y AND DETERMINED I HAD 5.5 MI AND INCREASING SO I ISSUED UGA X A 090 DEG HDG AND 6000 FT. WHEN I OBSERVED THAT THE EBOUND HDG WAS LOSING DISTANCE, I TURNED UGA Y TO A 270 DEG HDG BUT NOT SOON ENOUGH TO PREVENT A LOSS OF SEPARATION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE ACFT WERE ON DIVERGING COURSES. RPTR LOST SEPARATION AFTER TURNING LEAD ACFT PERPENDICULAR TO THE ESTABLISHED COURSE OF THE TRAILING ACFT WHICH ALLOWED THE INTERVAL BTWN ACFT TO CLOSE TO LESS THAN WAS REQUIRED.

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.