Narrative:

Simultaneous ILS approaches in use restricting departure headings. Weather was VMC; visibility restricted by haze; temperature in mid nineties. Arrival traffic was on the AML278 radial at 6;000 and approximately seven miles west of aml. The arrivals turn southbound at 6;000. TCAS RA events are an ato concern and pct has been advising personnel to limit risk of TCAS RA by alternate means. One such suggestion was to stop traffic climbing on departure 2;000 ft below other traffic. A B717 departed runway 30 heading 230 and was climbed to 4;000. An A320 was on AML278 heading 100 at 6;000. Once the B717 flew under the flight path of the A320; the B717 was climbed to 10;000 and turned to a heading of 190 to avoid additional traffic on AML278 radial. The A320 turned south as required by STAR at 6;000. The B717 climb rate was too slow and the turn was tight to a heading of 190 paralleling the A320 now also heading approximately 190. Recognizing the conflict; the B717 was issued 210 heading and issued traffic. With haze; the B717 was unable to see the A320. Three mile halo was placed on the B717 and the A320 was observed just inside halo. It was poor judgment on my part turning the B717 southbound and keeping the aircraft at 4;000 instead of 5;000 regardless of a potential TCAS RA that led to the loss of separation. Had the B717 been climbed to 5;000 and the same control actions executed; there wouldn't have been a loss of separation. Industry needs to evaluate the sensitivity of TCAS software to the common actions controllers execute daily. Pct's so called 'win-win' for flight crews and controllers; that being 2;000 ft separation preventing a TCAS RA events for the crew and no merging target procedures required for the controllers; isn't sound coaching.

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Original NASA ASRS Text

Title: A PCT Controller; when complying with facility suggested 'extra' altitude separation standards to avoid TCAS RA events; experienced a conflict event.

Narrative: Simultaneous ILS approaches in use restricting departure headings. Weather was VMC; visibility restricted by haze; temperature in mid nineties. Arrival traffic was on the AML278 radial at 6;000 and approximately seven miles west of AML. The arrivals turn southbound at 6;000. TCAS RA events are an ATO concern and PCT has been advising personnel to limit risk of TCAS RA by alternate means. One such suggestion was to stop traffic climbing on departure 2;000 FT below other traffic. A B717 departed Runway 30 heading 230 and was climbed to 4;000. An A320 was on AML278 heading 100 at 6;000. Once the B717 flew under the flight path of the A320; the B717 was climbed to 10;000 and turned to a heading of 190 to avoid additional traffic on AML278 radial. The A320 turned south as required by STAR at 6;000. The B717 climb rate was too slow and the turn was tight to a heading of 190 paralleling the A320 now also heading approximately 190. Recognizing the conflict; the B717 was issued 210 heading and issued traffic. With haze; the B717 was unable to see the A320. Three mile halo was placed on the B717 and the A320 was observed just inside halo. It was poor judgment on my part turning the B717 southbound and keeping the aircraft at 4;000 instead of 5;000 regardless of a potential TCAS RA that led to the loss of separation. Had the B717 been climbed to 5;000 and the same control actions executed; there wouldn't have been a loss of separation. Industry needs to evaluate the sensitivity of TCAS software to the common actions controllers execute daily. PCT's so called 'win-win' for flight crews and controllers; that being 2;000 FT separation preventing a TCAS RA events for the crew and no merging target procedures required for the controllers; isn't sound coaching.

Data retrieved from NASA's ASRS site as of April 2012 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.