Narrative:

I was en route from ack to bom, with VFR advisories being provided by new york approach on 135.9. I was cleared into class B airspace, and had passed overhead jfk, on a vector, with instructions to maintain 4500 ft while in class B airspace. The controller alerted me to heavy jet traffic climbing at my 2-3 O'clock position. I responded that I had the traffic in sight. Important note: I was utilizing my autoplt to maintain heading and altitude, in part so that I could maximize my 'heads up and outside' time. Both I and my passenger (also a pilot) watched the heavy jet climb. At a certain point, it looked as though it was headed directly for us. In retrospect, this may have been an optical illusion, but if it was, it was extremely convincing. Both my passenger and I exclaimed 'he's heading straight for us' at the same time. It seemed that an emergency evasive maneuver was required. I overrode the autoplt and dived in a steep left bank (jet approaching from right). As we descended through 4000 ft (jet now clearly level with us), the controller told me to climb immediately back to 4500 ft, and said that the jet was leveling at 4000 ft. (Major factor: the appearance that the jet would collide with us within seconds.) I returned to 4500 ft, and completed the flight without incident.

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Original NASA ASRS Text

Title: SMA PLT TOOK AVOIDANCE ACTION IN N90 CLASS B AIRSPACE AFTER IT APPEARED A HVY ACR ACFT PRESENTED A COLLISION HAZARD.

Narrative: I WAS ENRTE FROM ACK TO BOM, WITH VFR ADVISORIES BEING PROVIDED BY NEW YORK APCH ON 135.9. I WAS CLRED INTO CLASS B AIRSPACE, AND HAD PASSED OVERHEAD JFK, ON A VECTOR, WITH INSTRUCTIONS TO MAINTAIN 4500 FT WHILE IN CLASS B AIRSPACE. THE CTLR ALERTED ME TO HVY JET TFC CLBING AT MY 2-3 O'CLOCK POS. I RESPONDED THAT I HAD THE TFC IN SIGHT. IMPORTANT NOTE: I WAS UTILIZING MY AUTOPLT TO MAINTAIN HDG AND ALT, IN PART SO THAT I COULD MAXIMIZE MY 'HEADS UP AND OUTSIDE' TIME. BOTH I AND MY PAX (ALSO A PLT) WATCHED THE HVY JET CLB. AT A CERTAIN POINT, IT LOOKED AS THOUGH IT WAS HEADED DIRECTLY FOR US. IN RETROSPECT, THIS MAY HAVE BEEN AN OPTICAL ILLUSION, BUT IF IT WAS, IT WAS EXTREMELY CONVINCING. BOTH MY PAX AND I EXCLAIMED 'HE'S HDG STRAIGHT FOR US' AT THE SAME TIME. IT SEEMED THAT AN EMER EVASIVE MANEUVER WAS REQUIRED. I OVERRODE THE AUTOPLT AND DIVED IN A STEEP L BANK (JET APCHING FROM R). AS WE DSNDED THROUGH 4000 FT (JET NOW CLRLY LEVEL WITH US), THE CTLR TOLD ME TO CLB IMMEDIATELY BACK TO 4500 FT, AND SAID THAT THE JET WAS LEVELING AT 4000 FT. (MAJOR FACTOR: THE APPEARANCE THAT THE JET WOULD COLLIDE WITH US WITHIN SECONDS.) I RETURNED TO 4500 FT, AND COMPLETED THE FLT WITHOUT INCIDENT.

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.