Narrative:

I was conducting a routine traffic watch flight when the situation occurred. As always when flying this particular route, ms a, the traffic reporter, who also happens to be a student pilot, was assisting me with looking for other traffic. We were about halfway through the 2 hour flight when we were approaching the town of tarrytown from the east, heading towards the hudson river. It is a common routine for all traffic watch pilots to be reporting positions on a joint frequency unless operating in airspace where air traffic control communication is required. I had just reported my position on this frequency, when I noticed a helicopter coming my direction and at my altitude, at my 1-2 O'clock position. I estimate the distance to have been 1-1 1/2 mi. Ms. A pointed out the traffic simultaneously. Because of my position relative to the helicopter, I immediately started a left turn, while the helicopter, whose pilot apparently had yet not seen me, proceeded with no change in course. After passing the helicopter with a safe distance to his right, I switched to the hudson river unicom, which all VFR traffic is advised to use when operating in the hudson river corridor. This is also the frequency most commonly used by helicopter pilots, even when not operating directly over the hudson river. Once on the new frequency, I reported my position again, and advised I would be crossing the river on a westerly course. The helicopter pilot then furiously stated that I had almost caused a mid air collision. In the brief discussion that followed, I assured him that an accident was nowhere near to have happened, and added we had followed the recommended radio procedures. Afterwards, I discussed the incident with ms a who agreed that if anyone had been at fault, it was the helicopter pilot. He had obviously not complied with the basic rule of seeing and avoiding. If he had, he would undoubtedly have changed his course of flight. I believe the factors contributing to this situation primarily are as follows: the high density of VFR traffic operating in the new york metropolitan area, the fact that helicopter pilots, fully aware of the radio procedures conducted by fixed wing traffic reporter pilots as well as their frequencies, are failing to change frequencys once outside the hudson river corridor.

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Original NASA ASRS Text

Title: TFC WATCH ACFT HAS NMAC WITH HELI ALONG HUDSON RIVER CORRIDOR.

Narrative: I WAS CONDUCTING A ROUTINE TFC WATCH FLT WHEN THE SIT OCCURRED. AS ALWAYS WHEN FLYING THIS PARTICULAR RTE, MS A, THE TFC RPTR, WHO ALSO HAPPENS TO BE A STUDENT PLT, WAS ASSISTING ME WITH LOOKING FOR OTHER TFC. WE WERE ABOUT HALFWAY THROUGH THE 2 HR FLT WHEN WE WERE APCHING THE TOWN OF TARRYTOWN FROM THE E, HEADING TOWARDS THE HUDSON RIVER. IT IS A COMMON ROUTINE FOR ALL TFC WATCH PLTS TO BE RPTING POSITIONS ON A JOINT FREQ UNLESS OPERATING IN AIRSPACE WHERE AIR TFC CTL COM IS REQUIRED. I HAD JUST RPTED MY POS ON THIS FREQ, WHEN I NOTICED A HELI COMING MY DIRECTION AND AT MY ALT, AT MY 1-2 O'CLOCK POS. I ESTIMATE THE DISTANCE TO HAVE BEEN 1-1 1/2 MI. MS. A POINTED OUT THE TFC SIMULTANEOUSLY. BECAUSE OF MY POS RELATIVE TO THE HELI, I IMMEDIATELY STARTED A L TURN, WHILE THE HELI, WHOSE PLT APPARENTLY HAD YET NOT SEEN ME, PROCEEDED WITH NO CHANGE IN COURSE. AFTER PASSING THE HELI WITH A SAFE DISTANCE TO HIS R, I SWITCHED TO THE HUDSON RIVER UNICOM, WHICH ALL VFR TFC IS ADVISED TO USE WHEN OPERATING IN THE HUDSON RIVER CORRIDOR. THIS IS ALSO THE FREQ MOST COMMONLY USED BY HELI PLTS, EVEN WHEN NOT OPERATING DIRECTLY OVER THE HUDSON RIVER. ONCE ON THE NEW FREQ, I RPTED MY POS AGAIN, AND ADVISED I WOULD BE XING THE RIVER ON A WESTERLY COURSE. THE HELI PLT THEN FURIOUSLY STATED THAT I HAD ALMOST CAUSED A MID AIR COLLISION. IN THE BRIEF DISCUSSION THAT FOLLOWED, I ASSURED HIM THAT AN ACCIDENT WAS NOWHERE NEAR TO HAVE HAPPENED, AND ADDED WE HAD FOLLOWED THE RECOMMENDED RADIO PROCS. AFTERWARDS, I DISCUSSED THE INCIDENT WITH MS A WHO AGREED THAT IF ANYONE HAD BEEN AT FAULT, IT WAS THE HELI PLT. HE HAD OBVIOUSLY NOT COMPLIED WITH THE BASIC RULE OF SEEING AND AVOIDING. IF HE HAD, HE WOULD UNDOUBTEDLY HAVE CHANGED HIS COURSE OF FLT. I BELIEVE THE FACTORS CONTRIBUTING TO THIS SIT PRIMARILY ARE AS FOLLOWS: THE HIGH DENSITY OF VFR TFC OPERATING IN THE NEW YORK METROPOLITAN AREA, THE FACT THAT HELI PLTS, FULLY AWARE OF THE RADIO PROCS CONDUCTED BY FIXED WING TFC RPTR PLTS AS WELL AS THEIR FREQUENCIES, ARE FAILING TO CHANGE FREQS ONCE OUTSIDE THE HUDSON RIVER CORRIDOR.

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.