Great Starter Airplane 4-Channel Systems
  If you’re looking for a high-quality, 4-channel airplane radio, then look no further than Futaba’s own 4YF 2.4GHz FHSS Computer Radio. It has all of the features you’ll need.

Futaba 4YF 4-Channel FM Radio Systems

Tactic TTX404 4-Channel 2.4GHz Tx/Rx No Servos

Hitec Laser 4 4-Channel FM/4 HS-322 Servos

Sailplanes:
  In a sailplane, space and weight are very important. Choose a radio with smaller size servos for all but the largest of sailplanes. Since most sailplanes use only 2 channels, a 2-channel radio is all that is needed. A sailplane with a 2-channel radio is just about the least expensive way to get into the hobby of R/C flying. If your budget allows, go ahead and get a 4-channel now and just install only two of the servos. This will give you the safety and convenience of rechargeable NiCd batteries as a bonus.

Helicopters:
  What’s the difference between a helicopter radio and an airplane radio? If you are considering trying helicopters you should not attempt to start off by using an airplane radio. Considering the overall expense and specialization, your flying success will come much quicker with the aid of a specialized helicopter radio. Some of the features may be overwhelming at first, but if you get a good beginner/intermediate radio system you will quickly realize the need for these features and learn to use them.

Controlling Your Heli
  Though heli radios look like airplane radios, there are some very basic differences. For instance, most heli-capable radios include special mixing functions to simplify set-up, perform aerobatics and fine-tune performance. But the bigger difference between them is the number of control channels. Some sailplanes require just two; many airplanes can get by with four. Most helis, however, require at least five and sometimes six.

1. Left-Right Cyclic (Roll) - Makes the heli lean or tilt to either side.


2. Fore-Aft Cyclic (Pitch) - Moves the heli forward/backward. Push forward to move forward. Pull back to go backward.


3. Throttle/Collective Pitch - Controls engine speed and/or makes the heli go up or down.


4. Tail Rotor Pitch (Yaw) - Changes the heli’s direction by moving the nose left or right.


5. Gyro - Tail rotors can be hard to control, even for experienced modelers. Most pilots and manufacturers recommend using a gyro (scope) to help the yaw axis.

Great Starter Helicopter 6-Channel Systems

Futaba 6EX 6-Channel 2.4GHz Tx/Rx

Futaba 6EXP 6-Channel FM Computer Radios 72MHz

What comes with an Air Radio System?
  Most Aircraft Radio Systems come with:
Transmitter (Tx) - The hand-held radio controller. This is the unit that sends out the commands that you input.
Receiver (Rx) - The radio unit in the airplane which receives the transmitter signal and relays the control to the servos. This is somewhat similar to the radio you may have in your family automobile, except the radio receiver in the airplane perceives commands from the transmitter, while the radio in your car perceives music from the radio station.
Servo - The electromechanical device which moves the control surfaces or throttle of the airplane according to commands from the receiver. The radio device which does the physical work inside the airplane.
Batteries - 2 and 3 channel systems generally do not come with batteries and extra Alkaline "AA" batteries will be required. However most 4 or more channel radio systems will come with NiCd rechargeable battery packs for your receiver and transmitter and will include a charger. Check the requires section of the radio system you have chosen to make sure what is included and what is not.

There Are Four Different Frequency Groups To Choose From

1. Aircraft Use Only (72 megahertz, Channels 11 - 60): This is the most popular choice for flying models. Most radios designed for model aircraft and helicopters will be available on these channels.
   
2. Surface Use Only (75 megahertz, Channels 61-90): Cars, boats, and other non-flying models must use one of these channels. Radios designed for cars/boats exclusively with a steering wheel or pistol grip control are only available on these channels.
   
3. All Uses (27 megahertz, Channel Code A1-A6): Although legal for all models, we suggest that you use 27 megahertz only for surface models. This is because of the possibility that some unseen operator may innocently be operating a surface model on the same channel within range of your model airplane which would cause interference and a possible crash.
   
4. 2.4GHz Spread Spectrum Technology One of the most exciting new breakthroughs in hobby radio technology is the use of 2.4GHz spread spectrum technology -- which gives modelers of ALL skill levels the fastest, smoothest, most accurate and most reliable control possible. Futaba's 2.4GHz radio equipment in particular has advantages that greatly benefit new R/Cers. Simply by pushing a button, you link the receiver to a single transmitter -- each 2.4GHz transmitter has been assigned a unique ID code at the factory. Once that link is set, the receiver responds only to that one transmitter. In addition, Futaba 2.4GHz systems never stay on a single frequency for more than two milliseconds. You never have to worry about signal conflicts, and never need to wait for an open frequency when you're eager to enjoy a day of racing or flying with other modelers!
   Note: that countries outside the United States may offer different frequency allocation schemes