RE: futaba 9cap mix program for airbrake- flap and elevator
You can do it with PMIXes, but you will need three, one for each control surface. The first three PMIXes have all the parameters you need, unless you want exponential response from the elevator, then use the last PMIX for elevator. Note that you give up the elevator delay feature on the AIRBRAKE by not using switch "C".
Post on the manufaturer's subforum if you haven't.