When looking at a radio, you have to first set a budget along with your expected plans for flying.
You can fly most planes on a 4 channel standard radio. That gives you ailerons, elevator, throttle and rudder. If you want retracts, you need 5 channels.
The more important question is standard vs computer radio. Budget is the deciding factor here. Let me show you what you get for the extra $$ for a computer radio.
Computer radio vs. standard. Here is a concrete illustration of the value
of computer radios.
There is about a $45 difference between the Hitec Laser 4 standard and the
Hitec Flash 5X computer radios. What do you get for the extra money?
Channel 5, the retract channel. Now you can fly a plane with retracts.
That's cool, but perhaps not all that important to you.
Mixing is the real value here. Let's do a targeted discussion on mixing.
Let's focus on aileron mixing only.
You are flying your 4 channel glo or electric plane. You use R/E/T/A - rudder,
elevator, throttle and ailerons.
Standard 4 channel flies that fine. No issues at all.
Now, put it on a Flash 5X or many other computer radios that have at least 5 or 6
channels. Most will require you to go to 6 for splitting the ailerons to mix them. The flach 5X can do it on 5.
Put in two servos for the ailerons and assign them to different channels.
Under normal flight conditions the ailerons work exactly as before, but using
two servos; No difference. You are using a 2 channel aileron mix.
You are coming in for a landing. You turn on final approach to the runway and
line up for the center line. If you had flaps, here is where you would use
them, but your plane does not have flaps.
You level up the wings. At this point, you flip a switch on the flash 5X and
your ailerons just became flaps. You can still use the same stick and you can
still use the ailerons to bank/steer the plane, but they are both turned down
now so you will get a different aileron response than normal.
This is the flapperon mix. You now have the ability to come in much slower
which gives you a much softer more controlled landing. Flaps lower the stall
speed so you can fly at much slower speeds without stalling. Very useful!
That is surface mixing and that is what a computer radio can do for you.
Getting the idea?
Gliders. same idea - focus on ailerons.
Your next glider has ailerons. You can do the flaps as above, but you can
also flip that switch and make them spoilers.
Spoilers spoil the lift of the wing and help you bring the plane down in a
level flight path for a slide in on the belly landing. Without spoilers, if
your glider has too much energy and you are committed to landing, you
have to put the nose down which can result in a hard landing, or "glide it
out", if you have the room, until it comes to a rest and then take the long walk. You can't hit the gas and go around again, you have to come down somewhere. Spoilers make it easer
to control where.
Gliders have such efficient high lift wings and such light wing loading it can
be hard to get them down, especially in gusty conditions. Really! You have
to see it and feel it to understand. It is amazing!
I have one glider that has ailerons but no flaps or spoilers. I will be
setting up flapperons or spoilerons on that plane.
If you want to see what flap/aileron mixing looks like in motion, visit this
link. There are videos posted near the bottom of the page and you can watch
the surfaces move.
http://www.airfieldmodels.com/inform.../flaperons.htm
That is what you get for your $45. You get flaps and spoilers on planes that
don't have them and you can turn them on and off at will.
There are a lot more mixes. A lot, but hopefully you can relate to this
example. If you have 7 channels, like a Hitec Eclipse 7X, or 8 channles like a Futaba 9C, you can do even more, but you also have to spend more to get it.
Net net, if you budget can handle it, get a radio that will allow you to split and mix the ailerons. The Flash 5X is the lowest cost radio that I know that will do that. If you have more money, go for more.