Narrative:

Phx tower launched aircraft X (a C650) on the sjn 2 departure. Behind aircraft X, phx tower launched air carrier Y (a B733) on the tfd 1 departure. Air carrier Y was told to maintain visual separation from aircraft X (I assume). Air carrier Y was approximately 70-80 KTS faster than aircraft X. These departures are required to fly the same route until 4 DME east of phx. Aircraft X responded to an RA as air carrier Y overtook aircraft X. What caused this chain of events was the incorrect use of visual separation by the local controller at phx tower. This situation happens often and yet this procedure continues.

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Original NASA ASRS Text

Title: P50 DEP CTLR CONCERNED WITH RECURRENT PHX LCL CTLR MISAPPLICATION OF VISUAL SEPARATION BTWN MULTIPLE DEPS WHEN B737 OVERTAKES C650 ON INITIAL, COMMON SID ROUTING.

Narrative: PHX TWR LAUNCHED ACFT X (A C650) ON THE SJN 2 DEP. BEHIND ACFT X, PHX TWR LAUNCHED ACR Y (A B733) ON THE TFD 1 DEP. ACR Y WAS TOLD TO MAINTAIN VISUAL SEPARATION FROM ACFT X (I ASSUME). ACR Y WAS APPROX 70-80 KTS FASTER THAN ACFT X. THESE DEPS ARE REQUIRED TO FLY THE SAME RTE UNTIL 4 DME E OF PHX. ACFT X RESPONDED TO AN RA AS ACR Y OVERTOOK ACFT X. WHAT CAUSED THIS CHAIN OF EVENTS WAS THE INCORRECT USE OF VISUAL SEPARATION BY THE LCL CTLR AT PHX TWR. THIS SIT HAPPENS OFTEN AND YET THIS PROC CONTINUES.

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.