The Transport Accident Investigation Commission says a near collision between a helicopter and a small plane at New Plymouth Aerodrome could have been avoided with better communication.
The plane and helicopter were both being used for pilot training when they came close to colliding while circling the aerodrome in May last year.
The commission says the air traffic controller failed to manage the increased risk of collision and did not provide traffic information to the pilots of the helicopter.
It says the near collision could have been avoided if the aeroplane pilots had reported they had lost sight of the helicopter.
