One more thing. In addition to changing the trim settings when you switch planes, you'll probably have to reverse one or more of the servos. This depends on how each plane is set up. It's easy to do (there's a reversing switch on the transmitter for each channel), but if you forget and take off with your aileron servo reversed, there's a good chance you'll lose the plane. I've done it a time or two; I usually figure out what's wrong just as the plane hits the ground. So, before you start any plane, it's best to check that all the controls qre working in the right direction.