Narrative:

Departure control was very busy. Our flight was cleared to climb to 7000 ft. During the climb through 5000 ft, we spotted TCASII traffic at 1 O'clock position, 3 mi. It appeared to be level at 6500 ft, at which time we received a TCASII TA. Captain decreased the climb rate to 500 FPM as we attempted to query ATC. Unable to break into ATC communications, the captain elected to level off at 6000 ft and spot the traffic visually. The first officer and captain visually verified the single engine aircraft and watched it pass in front of our flight path. ATC chimed on with a turn command to both aircraft. As we turned to the right, the small craft passed off our left side 500 ft above and 1 1/2 mi lateral separation. Based on the closure rate this captain believes that, had he continued to climb to 7000 ft, we would have received an RA and been commanded to climb at an increased rate taking us through our assigned altitude of 7000 ft. At no time was this event noticed by the passenger or was any evasive action taken or necessary. This captain would prefer not to be placed in a position of climbing through a VFR aircraft altitude in such a busy environment. He is happy with the outcome but can see the possibility for a worsening situation had the event been handled differently.

Related reports:

Google
 

Original NASA ASRS Text

Title: B757 EXPERIENCED TFC CONFLICTION WITH TFC UNDER N90 CTLR WHILE ON N90 FREQ IN JFK CLASS B AIRSPACE.

Narrative: DEP CTL WAS VERY BUSY. OUR FLT WAS CLRED TO CLB TO 7000 FT. DURING THE CLB THROUGH 5000 FT, WE SPOTTED TCASII TFC AT 1 O'CLOCK POS, 3 MI. IT APPEARED TO BE LEVEL AT 6500 FT, AT WHICH TIME WE RECEIVED A TCASII TA. CAPT DECREASED THE CLB RATE TO 500 FPM AS WE ATTEMPTED TO QUERY ATC. UNABLE TO BREAK INTO ATC COMS, THE CAPT ELECTED TO LEVEL OFF AT 6000 FT AND SPOT THE TFC VISUALLY. THE FO AND CAPT VISUALLY VERIFIED THE SINGLE ENG ACFT AND WATCHED IT PASS IN FRONT OF OUR FLT PATH. ATC CHIMED ON WITH A TURN COMMAND TO BOTH ACFT. AS WE TURNED TO THE R, THE SMALL CRAFT PASSED OFF OUR L SIDE 500 FT ABOVE AND 1 1/2 MI LATERAL SEPARATION. BASED ON THE CLOSURE RATE THIS CAPT BELIEVES THAT, HAD HE CONTINUED TO CLB TO 7000 FT, WE WOULD HAVE RECEIVED AN RA AND BEEN COMMANDED TO CLB AT AN INCREASED RATE TAKING US THROUGH OUR ASSIGNED ALT OF 7000 FT. AT NO TIME WAS THIS EVENT NOTICED BY THE PAX OR WAS ANY EVASIVE ACTION TAKEN OR NECESSARY. THIS CAPT WOULD PREFER NOT TO BE PLACED IN A POS OF CLBING THROUGH A VFR ACFT ALT IN SUCH A BUSY ENVIRONMENT. HE IS HAPPY WITH THE OUTCOME BUT CAN SEE THE POSSIBILITY FOR A WORSENING SIT HAD THE EVENT BEEN HANDLED DIFFERENTLY.

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.