Narrative:

An E170 was eastbound at 4000 on downwind for runway 27R at phl. A VFR aircraft was on a converging heading from the southeast at 3600. I called traffic to the E170. I thought about turning him southbound to a base leg; however; I was already on a base leg with an aircraft from the other downwind at 4000. The VFR showed an altitude of 3700 when the E170 reported the traffic in sight. The aircraft responded to an RA and I alerted the supervisor. Recommendation; this is an ongoing problem here at phl. I don't understand why an aircraft at 4000; which is in the safe confines of the bravo airspace; has to be concerned with VFR's at these altitudes. The bravo airspace should be extended east and down to 1500. There is no reason why these VFR's can't transition the phl final and down winds at a lower altitude.

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Original NASA ASRS Text

Title: PHL TRACON described a TCAS RA event involving an IFR aircraft being vectored for a approach to Runway 27R and an unknown VFR target; the reporter suggesting changes to the Class B to increase air carrier protection.

Narrative: An E170 was Eastbound at 4000 on downwind for Runway 27R at PHL. A VFR aircraft was on a converging heading from the southeast at 3600. I called traffic to the E170. I thought about turning him southbound to a base leg; however; I was already on a base leg with an aircraft from the other downwind at 4000. The VFR showed an altitude of 3700 when the E170 reported the traffic in sight. The aircraft responded to an RA and I alerted the Supervisor. Recommendation; this is an ongoing problem here at PHL. I don't understand why an aircraft at 4000; which is in the safe confines of the Bravo airspace; has to be concerned with VFR's at these altitudes. The Bravo airspace should be extended east and down to 1500. There is no reason why these VFR's can't transition the PHL final and down winds at a lower altitude.

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.