Narrative:

Aircraft #1 requested a vector around VFR traffic that was 400 ft below and 5 mi away but converging. I issued a 120 degree heading for traffic. Aircraft #2 was level at 7000 ft and on a 250 degree heading for spacing. The 2 IFR aircraft were now on converging headings but were 1000 ft separated vertically. Aircraft #1 responded to a TCAS RA. When the VFR traffic was 2 1/2 mi away and passing on the right; the pilot did not advise of the RA. Aircraft #1 climbed to 6400 ft before descending. I had to ask the pilot if they responded to a TCAS RA; which they acknowledged. The TCAS climb reduced the separation between aircraft #1 and aircraft #2 to 4.2 mi laterally and 600 ft vertically when 5 mi; and 1000 ft is required. The 2 aircraft were still converging when #1 climbed. Aircraft #2 did not change altitude.

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Original NASA ASRS Text

Title: ZBW CTLR DESCRIBED CONFLICT BETWEEN TWO IFR ACFT WHEN ONE ACFT RESPONDED TO TCAS RA FROM KNOWN VFR TFC AND CLIMBED.

Narrative: ACFT #1 REQUESTED A VECTOR AROUND VFR TFC THAT WAS 400 FT BELOW AND 5 MI AWAY BUT CONVERGING. I ISSUED A 120 DEG HDG FOR TFC. ACFT #2 WAS LEVEL AT 7000 FT AND ON A 250 DEG HDG FOR SPACING. THE 2 IFR ACFT WERE NOW ON CONVERGING HDGS BUT WERE 1000 FT SEPARATED VERTICALLY. ACFT #1 RESPONDED TO A TCAS RA. WHEN THE VFR TFC WAS 2 1/2 MI AWAY AND PASSING ON THE R; THE PLT DID NOT ADVISE OF THE RA. ACFT #1 CLBED TO 6400 FT BEFORE DSNDING. I HAD TO ASK THE PLT IF THEY RESPONDED TO A TCAS RA; WHICH THEY ACKNOWLEDGED. THE TCAS CLB REDUCED THE SEPARATION BTWN ACFT #1 AND ACFT #2 TO 4.2 MI LATERALLY AND 600 FT VERTICALLY WHEN 5 MI; AND 1000 FT IS REQUIRED. THE 2 ACFT WERE STILL CONVERGING WHEN #1 CLBED. ACFT #2 DID NOT CHANGE ALT.

Data retrieved from NASA's ASRS site as of May 2009 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.