Narrative:

I was taking off from an uncontrolled airport with a 30 foot wide runway; length 4;800 ft; density altitude about 8;000. The (unpublished) preferred calm wind runway is 27. There is a 1% upward slope on 27; and there was a slight wind from the east; so taking off on 9 would have been plausible. I had just flown with a resident of the airpark about a half hour earlier (under similar wind); and he said he recommended 27 with such a light wind. The rv-9A I was flying has enough performance to take off in about a third of the runway length in these circumstances; but other; lower performance aircraft might well elect runway 9. I monitored CTAF while taxiing and don't recall hearing any calls. I announced before entering 27 that I was departing 27: 'XXX traffic; YYY departing runway 27; northbound departure XXX.' I didn't hear any radio calls; and I didn't see anyone in the pattern or on the runway. On takeoff roll; with nose wheel off the runway; maybe 50 KTS; I thought I saw something in the distance in front of me - a silhouette; no lights. Two or three seconds later; I discerned the aircraft heading toward me on runway 9; maybe 20 ft AGL. I couldn't tell if it was landing or taking off. I lifted off and made an immediate right turn to get away from the centerline - while I was in the turn; maybe two to three seconds after lifting off; the opposing aircraft passed me opposite direction and made a radio call: 'copter XXXX [didn't catch the number] - traffic now in sight.' with such a narrow runway; not knowing whether the oncoming aircraft was landing or taking off; and not familiar with copters; I felt that aborting my takeoff was not a good option. I don't know if he made a call that I missed (either due to the geography; or I just didn't hear it); or if he just turned his radio on after my call. I'm not sure how to interpret the other aircraft's call; 'now in sight.' it is possible the other pilot interpreted my radio call to mean I had already taken off and was in the process of leaving the area to the north - if this is how my call was interpreted; the pilot could have concluded the runway was unoccupied. My radio call could have been clearer: 'XXX traffic; YYY departing 27; planning right turnout; north departure XXX.' the use of 'planning' in the call might have kept the other pilot; if he was on frequency; from assuming I was already clear to the north.

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Original NASA ASRS Text

Title: The pilot of a single engine aircraft departed 1N1 Runway 27 after making CTAF traffic calls and took evasive action from a small helicopter taking off on Runway 9 but not making traffic calls.

Narrative: I was taking off from an uncontrolled airport with a 30 foot wide runway; length 4;800 FT; density altitude about 8;000. The (unpublished) preferred calm wind runway is 27. There is a 1% upward slope on 27; and there was a slight wind from the east; so taking off on 9 would have been plausible. I had just flown with a resident of the airpark about a half hour earlier (under similar wind); and he said he recommended 27 with such a light wind. The RV-9A I was flying has enough performance to take off in about a third of the runway length in these circumstances; but other; lower performance aircraft might well elect Runway 9. I monitored CTAF while taxiing and don't recall hearing any calls. I announced before entering 27 that I was departing 27: 'XXX traffic; YYY departing Runway 27; northbound departure XXX.' I didn't hear any radio calls; and I didn't see anyone in the pattern or on the runway. On takeoff roll; with nose wheel off the runway; maybe 50 KTS; I thought I saw something in the distance in front of me - a silhouette; no lights. Two or three seconds later; I discerned the aircraft heading toward me on Runway 9; maybe 20 FT AGL. I couldn't tell if it was landing or taking off. I lifted off and made an immediate right turn to get away from the centerline - while I was in the turn; maybe two to three seconds after lifting off; the opposing aircraft passed me opposite direction and made a radio call: 'Copter XXXX [didn't catch the number] - traffic now in sight.' With such a narrow runway; not knowing whether the oncoming aircraft was landing or taking off; and not familiar with copters; I felt that aborting my takeoff was not a good option. I don't know if he made a call that I missed (either due to the geography; or I just didn't hear it); or if he just turned his radio on after my call. I'm not sure how to interpret the other aircraft's call; 'now in sight.' It is possible the other pilot interpreted my radio call to mean I had already taken off and was in the process of leaving the area to the north - if this is how my call was interpreted; the pilot could have concluded the runway was unoccupied. My radio call could have been clearer: 'XXX traffic; YYY departing 27; planning right turnout; north departure XXX.' The use of 'planning' in the call might have kept the other pilot; if he was on frequency; from assuming I was already clear to the north.

Data retrieved from NASA's ASRS site as of July 2013 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.