Narrative:

After passing hayed intersection on the williamsport 1 arrival to ewr and level at 17000 ft, ATC gave us an 'unidented traffic at 11 O'clock, altitude shows 16600 unconfirmed.' our TCASII showed traffic at 11:30, -500 ft for a second, immediately after, it showed -300 ft and a TA which turned into an RA very rapidly, with a climb command. I initiated a climb and advised ATC. There were no other conflicts and ATC confirmed this. TCASII works.

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Original NASA ASRS Text

Title: AN ACR MLG CLBED IN RESPONSE TO A TCASII COMMAND. THE INTRUDER WAS VFR. THERE WAS MIN TIME OF WARNING BY ATC.

Narrative: AFTER PASSING HAYED INTXN ON THE WILLIAMSPORT 1 ARR TO EWR AND LEVEL AT 17000 FT, ATC GAVE US AN 'UNIDENTED TFC AT 11 O'CLOCK, ALT SHOWS 16600 UNCONFIRMED.' OUR TCASII SHOWED TFC AT 11:30, -500 FT FOR A SECOND, IMMEDIATELY AFTER, IT SHOWED -300 FT AND A TA WHICH TURNED INTO AN RA VERY RAPIDLY, WITH A CLB COMMAND. I INITIATED A CLB AND ADVISED ATC. THERE WERE NO OTHER CONFLICTS AND ATC CONFIRMED THIS. TCASII WORKS.

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.