ORIGINAL: stockdaddy
Rudder, throttle, elevator, ailerons can actually use 5 ch's when u have 2 independent servos for the ailerons.
On the Hitec Flash 5SX and a few others you can do this with a 5 channel radio and a 5 channel receiver. But most of hte time you need a 6 channel computer radio to have separate channels for your aileron servos. Makes life so much easier when you are trimming the ailerons. And of course you can now invole flapperons or ailreon differential if you wish.
All of this requires a computer radio.