Narrative:

Aircraft X departed stl on a 360 degree heading. When he was approximately 4 mi north aircraft Y departed on a 330 degree heading, and aircraft Y subsequently did not tag up until 4 mi northwest. The separation had decreased to less than 5 mi by the time he tagged up. I stopped aircraft X at 40 when the jet finally tagged up, stl tower had coordinated with another controller using a 330 degree heading for jets and 360 degree for propellers but, would have 1 of the aircraft use visual separation. In this case, the propeller was too far out to use visual, but the jet caught him very rapidly. Our standard procedure is to use 45 degree separation, but someone had different ideas. I was working low altitude north and on numerous occasions lost radar contact with traffic. I think someone put too much emphasis on departing aircraft, than on safety. The non-radar headings should be used.

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Original NASA ASRS Text

Title: CTLR INTERVENED TO MAINTAIN STANDARD SEPARATION BTWN ACFT X AND ACFT Y. VISUAL SEPARATION IN USE.

Narrative: ACFT X DEPARTED STL ON A 360 DEG HDG. WHEN HE WAS APPROX 4 MI N ACFT Y DEPARTED ON A 330 DEG HDG, AND ACFT Y SUBSEQUENTLY DID NOT TAG UP UNTIL 4 MI NW. THE SEPARATION HAD DECREASED TO LESS THAN 5 MI BY THE TIME HE TAGGED UP. I STOPPED ACFT X AT 40 WHEN THE JET FINALLY TAGGED UP, STL TWR HAD COORDINATED WITH ANOTHER CTLR USING A 330 DEG HDG FOR JETS AND 360 DEG FOR PROPS BUT, WOULD HAVE 1 OF THE ACFT USE VISUAL SEPARATION. IN THIS CASE, THE PROP WAS TOO FAR OUT TO USE VISUAL, BUT THE JET CAUGHT HIM VERY RAPIDLY. OUR STANDARD PROC IS TO USE 45 DEG SEPARATION, BUT SOMEONE HAD DIFFERENT IDEAS. I WAS WORKING LOW ALT N AND ON NUMEROUS OCCASIONS LOST RADAR CONTACT WITH TFC. I THINK SOMEONE PUT TOO MUCH EMPHASIS ON DEPARTING ACFT, THAN ON SAFETY. THE NON-RADAR HDGS SHOULD BE USED.

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.