ORIGINAL: TimChurch
The purpose is that someone thought it would make it easier. The fact is it is in no way needed to 3d and will more then likely cause more problems then any good it can do.
Honestly if I bought a 3D plane with a gyro, it would be removed prior to first flight. If a plane needs a gyro to 3d look for a diffrent plane.
The purpose = to control one or more surface to keep plane pointed in a certain direction
AE one on the rudder would operate the rudder, you could point the nose up flip the gyro on and it would move rudder direction needed to keep the nose pointed up. Add it to the ailerons and elevator and it would do the same and all you would be doing is controling the throttle.
You don't need it to learn 3d and people don't use them, anybody that does is playing with gadgets and not really wanting to fly 3d..
BTW build yourself a MOJO 60 and put a Saito 100 in it , and have fun learning 3d
Its not that the plane needs it, its because the person in control is too lazy to learn 3d. They don't have total control of the surface, I have heard it compared to what it would be like to fly underwater, all the movements are slower and easier to compensate for. I would not like it, because it also makes it less responsive to control input, so if a rouge gust of wind rolls by your screwed because you are going to have a hard time saving it if you are low to the ground.