R/C Helicopters are controlled by rc transmitter(TX). You can move the stick and the rc helicopter will follow(interpret the signal as move) to certain turn. A R/C radio transmitter can control the rc helicopter model approximately one mile away. Actually it's limited range, but all this is depend the pilot's ability to follow and control it so you still fly in your eye. Controlling R/C helicopter is more complex than controlling r/c car. There are four functions to control in a full-sized radio control helicopters. First is THROTTLE and COLLECTIVE PITCH, to make the rc helicopter go up you need to increase engine power and added collectively the pitch of the main rotor blades. So the throttle and collective pitch of the main rotor blades is mixed together. Second is The Tail Rotor Blades, without the tail rotor blades your rc helicopter will spinning arround out of control, this because tail rotor blades will counteract the engine power torque. Third is The Fore-Aft Cyclic, it control changes the pitch of the main rotor blades only at one point around each 360 degree revolution of the rotor blades in cycles or cyclically. Fourth is The LEFT-RIGHT CYCLIC, it's same as described for fore-aft cyclic except that the pitch of the main rotor blades changes at a different point (90 degrees later) throughout each 360 degree revolution in order to "bank" the helicopter to the right or left.