Narrative:

The other aircraft involved was a black (or dark color) helicopter, apparently turbine pwred. I was northbound in the hudson river VFR corridor at 800 MSL (had set altimeter to kennedy setting) near the east bank, in the area typically used for northbound flight to avoid conflicts. I had approximately 1 min before announced my position and intentions on the self- announce frequency (123.05) when I was over the intrepid, a common reporting point. At approximately the same time, or just before, an aircraft announced it was proceeding wbound over midtown/central park. As I approached the midtown area, I saw the helicopter proceeding wbound. It appeared that it would cross my path e-w well clear before I approached its hudson river crossing point. However, on reaching the river, the helicopter slowed, appeared to hover/turn at 180 degrees facing east. Suddenly, as I began to react by slowing, it abruptly turned south, southeast and proceeded toward me at approximately my altitude at a high speed. It approached from my 1-2 O'clock position. I began evasive action by slowing, diving and banking/turning to my left. I leveled at 650 ft MSL. The helicopter also turned left to avoid collision and appeared to ascend slightly. Certain controls on abrupt helicopter movements in this VFR corridor may help avoid similar incidents in the future. A contributing factor may have been the fact that the self- announce frequency is often clogged/dominated by FBO ground activities, apparently at a heliport(south) in south manhattan. This impedes aircraft attempting to make position and intention reports. It is conceivable, although I don't think this actually occurred, that the helicopter reported his intention to turn southward, and his transmission was stepped on by the FBO. The FBO(south) should operate on a different frequency for safety reasons.

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Original NASA ASRS Text

Title: SMA HAS NMAC WITH HELI OVER THE HUDSON RIVER.

Narrative: THE OTHER ACFT INVOLVED WAS A BLACK (OR DARK COLOR) HELI, APPARENTLY TURBINE PWRED. I WAS NBOUND IN THE HUDSON RIVER VFR CORRIDOR AT 800 MSL (HAD SET ALTIMETER TO KENNEDY SETTING) NEAR THE E BANK, IN THE AREA TYPICALLY USED FOR NBOUND FLT TO AVOID CONFLICTS. I HAD APPROX 1 MIN BEFORE ANNOUNCED MY POS AND INTENTIONS ON THE SELF- ANNOUNCE FREQ (123.05) WHEN I WAS OVER THE INTREPID, A COMMON RPTING POINT. AT APPROX THE SAME TIME, OR JUST BEFORE, AN ACFT ANNOUNCED IT WAS PROCEEDING WBOUND OVER MIDTOWN/CENTRAL PARK. AS I APCHED THE MIDTOWN AREA, I SAW THE HELI PROCEEDING WBOUND. IT APPEARED THAT IT WOULD CROSS MY PATH E-W WELL CLR BEFORE I APCHED ITS HUDSON RIVER XING POINT. HOWEVER, ON REACHING THE RIVER, THE HELI SLOWED, APPEARED TO HOVER/TURN AT 180 DEGS FACING E. SUDDENLY, AS I BEGAN TO REACT BY SLOWING, IT ABRUPTLY TURNED S, SE AND PROCEEDED TOWARD ME AT APPROX MY ALT AT A HIGH SPD. IT APCHED FROM MY 1-2 O'CLOCK POS. I BEGAN EVASIVE ACTION BY SLOWING, DIVING AND BANKING/TURNING TO MY L. I LEVELED AT 650 FT MSL. THE HELI ALSO TURNED L TO AVOID COLLISION AND APPEARED TO ASCEND SLIGHTLY. CERTAIN CTLS ON ABRUPT HELI MOVEMENTS IN THIS VFR CORRIDOR MAY HELP AVOID SIMILAR INCIDENTS IN THE FUTURE. A CONTRIBUTING FACTOR MAY HAVE BEEN THE FACT THAT THE SELF- ANNOUNCE FREQ IS OFTEN CLOGGED/DOMINATED BY FBO GND ACTIVITIES, APPARENTLY AT A HELIPORT(S) IN SOUTH MANHATTAN. THIS IMPEDES ACFT ATTEMPTING TO MAKE POS AND INTENTION RPTS. IT IS CONCEIVABLE, ALTHOUGH I DON'T THINK THIS ACTUALLY OCCURRED, THAT THE HELI RPTED HIS INTENTION TO TURN SOUTHWARD, AND HIS XMISSION WAS STEPPED ON BY THE FBO. THE FBO(S) SHOULD OPERATE ON A DIFFERENT FREQ FOR SAFETY REASONS.

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.