Try hitting different switches one at a time OR turn the knob, THEN hit "RESET". Reading the description on the biplane, it`s the knob that detaches /attaches it. I`m not sure about the low wing version. It would be nice to know what plane you have exactly, and what TX you`re using.I imported this plane into RF Evolution and when I spawn the plane the spray bar automatically detaches and falls on the ground. Any idea what's going on? Seems to function ok otherwise.