The chopper occupants were doing an auto rotation manoeuvre and Bevan Hookway was making preparations to land the light plane when they collided. There had been no hint of trouble beforehand.
The R22 fell through the roof of Placemakers' store in Paraparaumu, narrowly missing staff and customers. The plane fuselage landed about 250 metres away in a cul-de-sac and the engine smashed onto a house.
Ms Woodcock said helicopter training was no longer allowed to be based at Kapiti Coast Airport and the former operation had relocated to Palmerston North.
A separate area of the aerodrome had since been allocated for helicopter use, and choppers and fixed-wing aircraft now both used either right or left handed circuits above the airport when looking to land. At the time of the collision, they flew opposing circuits - a practice discouraged by the Civil Aviation Society.
Circuit height had reverted to 1000 feet above ground level for fixed wing aircraft and 800ft for choppers since the accident, she said.
It had been the standard 1000ft for both types at the time of the mid-air crash - raised for helicopters after complaints from nearby residents of noise levels.
The conflict caused by the old circuit system and by the multi-use of the airport by different types of aircraft has come under scrutiny during the inquest.
At one stage today the coroner wondered aloud if the aerodrome had been "a bit Mickey Mouse'' before it was certificated, when the CAA had limited power over procedures and operations.
The inquest is due to finish tomorrow.