Narrative:

I was cruising at 8500' with 1 non-pilot passenger, at approximately 155 KTS indicated. I had taken off from islip and at that point was navigating at about 245 degrees to colts neck VOR, in radio contact with north.Y. Approach, who were giving me traffic advisories. I watched 1 plane, which had apparently taken off from runway 22 at jfk, make a climbing turn to the northeast, well in front of me, and I had the second plane in sight as it followed a similar path. The controller told me the widebody transport was cleared to 8000'. I was on altitude hold at 8500', having recently checked my altimeter setting. As the widebody transport approached, closing fast at about a 30-45 degree angle from my left, my perception was that we were on a collision course and that he did not seem to be leveling (changing attitude).I did not have time for too many thoughts--'turn toward his tail?' I couldn't see it. 'Climb?' that seemed to be his apparent path and I could never out-climb him--so I descended rapidly down to no less than 7500'. He passed (apparently) directly overhead. I would have guessed 700-800' above me. I did not experience any wake turbulence and I climbed right back to 8500' and continued my flight. I subsequently spoke to the supervisor, and later to the controller. He told me he saw 8200' for the widebody transport on mode C on his screen, and asked the air carrier pilot to confirm his altitude. He replied that he was at 8050'. This is an interesting situation since everybody was doing what they were supposed to be doing and the WX was no factor. The controller said 'the heading that I gave that aircraft was in no way intended to bring him so close to you, but the heading I gave him didn't concern me knowing that I was going to have 500' (sep).'

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Original NASA ASRS Text

Title: NMAC.

Narrative: I WAS CRUISING AT 8500' WITH 1 NON-PLT PAX, AT APPROX 155 KTS INDICATED. I HAD TAKEN OFF FROM ISLIP AND AT THAT POINT WAS NAVIGATING AT ABOUT 245 DEGS TO COLTS NECK VOR, IN RADIO CONTACT WITH N.Y. APCH, WHO WERE GIVING ME TFC ADVISORIES. I WATCHED 1 PLANE, WHICH HAD APPARENTLY TAKEN OFF FROM RWY 22 AT JFK, MAKE A CLBING TURN TO THE NE, WELL IN FRONT OF ME, AND I HAD THE SECOND PLANE IN SIGHT AS IT FOLLOWED A SIMILAR PATH. THE CTLR TOLD ME THE WDB WAS CLRED TO 8000'. I WAS ON ALT HOLD AT 8500', HAVING RECENTLY CHKED MY ALTIMETER SETTING. AS THE WDB APCHED, CLOSING FAST AT ABOUT A 30-45 DEG ANGLE FROM MY LEFT, MY PERCEPTION WAS THAT WE WERE ON A COLLISION COURSE AND THAT HE DID NOT SEEM TO BE LEVELING (CHANGING ATTITUDE).I DID NOT HAVE TIME FOR TOO MANY THOUGHTS--'TURN TOWARD HIS TAIL?' I COULDN'T SEE IT. 'CLB?' THAT SEEMED TO BE HIS APPARENT PATH AND I COULD NEVER OUT-CLB HIM--SO I DSNDED RAPIDLY DOWN TO NO LESS THAN 7500'. HE PASSED (APPARENTLY) DIRECTLY OVERHEAD. I WOULD HAVE GUESSED 700-800' ABOVE ME. I DID NOT EXPERIENCE ANY WAKE TURB AND I CLBED RIGHT BACK TO 8500' AND CONTINUED MY FLT. I SUBSEQUENTLY SPOKE TO THE SUPVR, AND LATER TO THE CTLR. HE TOLD ME HE SAW 8200' FOR THE WDB ON MODE C ON HIS SCREEN, AND ASKED THE ACR PLT TO CONFIRM HIS ALT. HE REPLIED THAT HE WAS AT 8050'. THIS IS AN INTERESTING SITUATION SINCE EVERYBODY WAS DOING WHAT THEY WERE SUPPOSED TO BE DOING AND THE WX WAS NO FACTOR. THE CTLR SAID 'THE HDG THAT I GAVE THAT ACFT WAS IN NO WAY INTENDED TO BRING HIM SO CLOSE TO YOU, BUT THE HDG I GAVE HIM DIDN'T CONCERN ME KNOWING THAT I WAS GOING TO HAVE 500' (SEP).'

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.