Little Fixes for Default Wabo AYWB

Enhance the default Wabo AYWB airport with this add-on featuring a change from asphalt to gravel runway, fixed river, trees, terrain adjustments, and an added helipad. Coordinates -6.989444, 145.075. Compatibility with Mikea.at asset pack for visible cones on the runway. Fix courtesy of Missionary Bush Pilots Goroka - Wabo video. Enjoy improved flying experience!