There will be 6 analog and 5 digital input. And arduino will convert these inputs to both USB game controller and Futaba buddy port.
USB game controller will work with windows and mac.
You can find details about futaba output in following URL.
[url removed, login to view];view=article&id=30:project-rc-ppm-trainer-port-joystick
Arduino will be able to give both futaba and USB game controller outputs at the same time.