AA=5 pilot departing a non-towered airport reported a NMAC with an opposite direction helicopter landing on a taxiway parallel to the runway.

Narrative

I was conducting pattern work in A Grumman Traveler (AA-5) at ZZZ. There was a second aircraft in the pattern. We were both in left traffic for RWY XX. While on the left downwind for RWY XX; a helicopter (AW139) approached from the west and announced entering a right base for RWY XY. At this point; I turned and announced turning onto the left base for RWY XX. The second aircraft announced that he was on a 5nm final for RWY XX. Due to radio traffic congestion and configuring for the landing; I was unable to radio the helicopter and inform him of traffic in the pattern; but assumed that the helicopter had both of us transmitting our position and intentions. I turned on to final; made a radio call that I was on final for a touch and go and remaining in the pattern. The traffic on long final; behind me was too close to me and announced that he was continuing on the upwind for RWY XX. Upon touchdown; I applied full throttle and began my takeoff. As I was announcing that I was on the go; I saw the helicopter on short final for RWY XY; proceeding directly towards me; and told the helicopter that I was on the go and to get out of the pattern. The helicopter announced that he had sidestepped over the parallel taxiway and that he saw us. Fortunately; I was able to avoid any of his rotorwash as we passed each other horizontally at the same altitude over the runway environment. I remained in the pattern for one more cycle and made a full stop landing.After the landing; I approached the helicopter pilots about what happened and they said that they saw me in the pattern and were lined up on the parallel taxiway (TXY 1) on final and that it was safe and in accordance with the FAR and AIM. What caused the problem? Clearly; the helicopter pilots felt they were complying with 91.126(b)(2) 'Each pilot of a helicopter or a powered parachute must avoid the flow of fixed-wing aircraft.' I explained that I felt that making an opposite direction approach over a parallel taxiway to a runway in use was not in compliance with 91.126. This appears to be a case of interpretation of current guidelines. I spoke to other helicopter pilots after this happened and they agreed that it didn't seem to violate any regulations; however; they also said that they would never land against fixed wing traffic.