Narrative:

I was performing aerial photography at 1000 ft AGL about 2-3 mi west of downtown columbus, oh. The aircraft has a ryan 8800 tcad which indicated a traffic conflict at the same altitude and 1.5 mi (I had it in terminal mode at the time, +/-500 ft and 1.5 mi). I was not talking to columbus because I was below their class C airspace and they were busy with arrs. The target closed to within 1 mi at which time I descended to avoid a conflict in altitude. I idented the target as an unknown helicopter and continued photographing my site at the lower altitude which involved circling back up to 1000 ft AGL. The same piece of traffic reappeared once again and made several passes at me at my altitude and at tcad indicated distances of 0.3 to 1 mi. Upon landing and calling columbus FSDO, I was told the traffic was a state police helicopter which had filed a complaint that I was flying 'low and erratic' over a populated area. I descended below the minimum altitude to avoid a traffic conflict (a cardinal can descend much faster than it can climb). I was operating at a safe and legal altitude before the conflict and climbed back up to that legal altitude after the threat left the area. Did not appreciate the state police helicopter pilot making several close passes to get my tail number. If this situation presents itself again, I will establish communication with the local ATC so that they know where I am and what I am doing.

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Original NASA ASRS Text

Title: C177 PLT HAD CLOSE ENCOUNTER WITH POLICE HELI THAT REQUIRED PLT TO TAKE EVASIVE ACTION. THE HELI THEN MADE REPEATED PASSES ON THE RPTR'S ACFT.

Narrative: I WAS PERFORMING AERIAL PHOTOGRAPHY AT 1000 FT AGL ABOUT 2-3 MI W OF DOWNTOWN COLUMBUS, OH. THE ACFT HAS A RYAN 8800 TCAD WHICH INDICATED A TFC CONFLICT AT THE SAME ALT AND 1.5 MI (I HAD IT IN TERMINAL MODE AT THE TIME, +/-500 FT AND 1.5 MI). I WAS NOT TALKING TO COLUMBUS BECAUSE I WAS BELOW THEIR CLASS C AIRSPACE AND THEY WERE BUSY WITH ARRS. THE TARGET CLOSED TO WITHIN 1 MI AT WHICH TIME I DSNDED TO AVOID A CONFLICT IN ALT. I IDENTED THE TARGET AS AN UNKNOWN HELI AND CONTINUED PHOTOGRAPHING MY SITE AT THE LOWER ALT WHICH INVOLVED CIRCLING BACK UP TO 1000 FT AGL. THE SAME PIECE OF TFC REAPPEARED ONCE AGAIN AND MADE SEVERAL PASSES AT ME AT MY ALT AND AT TCAD INDICATED DISTANCES OF 0.3 TO 1 MI. UPON LNDG AND CALLING COLUMBUS FSDO, I WAS TOLD THE TFC WAS A STATE POLICE HELI WHICH HAD FILED A COMPLAINT THAT I WAS FLYING 'LOW AND ERRATIC' OVER A POPULATED AREA. I DSNDED BELOW THE MINIMUM ALT TO AVOID A TFC CONFLICT (A CARDINAL CAN DSND MUCH FASTER THAN IT CAN CLB). I WAS OPERATING AT A SAFE AND LEGAL ALT BEFORE THE CONFLICT AND CLBED BACK UP TO THAT LEGAL ALT AFTER THE THREAT LEFT THE AREA. DID NOT APPRECIATE THE STATE POLICE HELI PLT MAKING SEVERAL CLOSE PASSES TO GET MY TAIL NUMBER. IF THIS SIT PRESENTS ITSELF AGAIN, I WILL ESTABLISH COM WITH THE LCL ATC SO THAT THEY KNOW WHERE I AM AND WHAT I AM DOING.

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.