Narrative:

Following a short VFR test flight; I began entry into the VFR traffic pattern at ZZZ. Conditions were clear unlimited visibility with light winds favoring runway xx. I entered the normal l-hand traffic pattern at pattern altitude on the upwind leg. Progressing through the pattern; I made 4 TA's on the CTAF of 122.8. There were no other advisories heard on the frequency or other aircraft seen when searching the local area. I was also monitoring the approach control frequency and did hear at least 1 attempt by them to contact a helicopter apparently trying to discontinue radar service. There was no response heard from the helicopter and no location was noted. On short final approach at about 1/2 mi from the end of the runway and approximately 400 ft AGL; the FBO attendant broadcast; 'do you see the helicopter?' I responded 'no; where?' the attendant correctly idented the location 'off your right wing.' at this point; I observed the helicopter emerge from the blind area below my right wing flying right to left across the approach end of the runway at approximately 100 ft AGL. I took evasive action initiating a climbing right turn to avoid the helicopter and aborting the landing approach. After landing; in discussions with the helicopter pilot; he acknowledged not being on the CTAF; not making any TA's and apologized for his actions. Several ground witnesses observed the helicopter flying at high speed and low altitude wbound near the airport southern boundary and making a rapid turn over the airport boundary and proceeding directly to a ramp on the west side of the airport. I credit the alert response of the FBO attendant with the prevention of a possible midair collision.

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Original NASA ASRS Text

Title: EXPERIMENTAL ACFT PILOT REPORTS NMAC WITH HELICOPTER ON SHORT FINAL.

Narrative: FOLLOWING A SHORT VFR TEST FLT; I BEGAN ENTRY INTO THE VFR TFC PATTERN AT ZZZ. CONDITIONS WERE CLR UNLIMITED VISIBILITY WITH LIGHT WINDS FAVORING RWY XX. I ENTERED THE NORMAL L-HAND TFC PATTERN AT PATTERN ALT ON THE UPWIND LEG. PROGRESSING THROUGH THE PATTERN; I MADE 4 TA'S ON THE CTAF OF 122.8. THERE WERE NO OTHER ADVISORIES HEARD ON THE FREQ OR OTHER ACFT SEEN WHEN SEARCHING THE LCL AREA. I WAS ALSO MONITORING THE APCH CTL FREQ AND DID HEAR AT LEAST 1 ATTEMPT BY THEM TO CONTACT A HELI APPARENTLY TRYING TO DISCONTINUE RADAR SVC. THERE WAS NO RESPONSE HEARD FROM THE HELI AND NO LOCATION WAS NOTED. ON SHORT FINAL APCH AT ABOUT 1/2 MI FROM THE END OF THE RWY AND APPROX 400 FT AGL; THE FBO ATTENDANT BROADCAST; 'DO YOU SEE THE HELI?' I RESPONDED 'NO; WHERE?' THE ATTENDANT CORRECTLY IDENTED THE LOCATION 'OFF YOUR R WING.' AT THIS POINT; I OBSERVED THE HELI EMERGE FROM THE BLIND AREA BELOW MY R WING FLYING R TO L ACROSS THE APCH END OF THE RWY AT APPROX 100 FT AGL. I TOOK EVASIVE ACTION INITIATING A CLBING R TURN TO AVOID THE HELI AND ABORTING THE LNDG APCH. AFTER LNDG; IN DISCUSSIONS WITH THE HELI PLT; HE ACKNOWLEDGED NOT BEING ON THE CTAF; NOT MAKING ANY TA'S AND APOLOGIZED FOR HIS ACTIONS. SEVERAL GND WITNESSES OBSERVED THE HELI FLYING AT HIGH SPD AND LOW ALT WBOUND NEAR THE ARPT SOUTHERN BOUNDARY AND MAKING A RAPID TURN OVER THE ARPT BOUNDARY AND PROCEEDING DIRECTLY TO A RAMP ON THE W SIDE OF THE ARPT. I CREDIT THE ALERT RESPONSE OF THE FBO ATTENDANT WITH THE PREVENTION OF A POSSIBLE MIDAIR COLLISION.

Data retrieved from NASA's ASRS site as of May 2009 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.