New To R/C - Read Our Intro's to Model Flying

Getting To Know R/C Model Gliders
R/C model glider or sailplane are an excellent way to get into the R/C aircraft hobby and have the advantage that it is less expensive less complicated than powered aircraft. Even though a glider does not have an engine, it can stay in the air for long periods of time and can fly at high speeds, depending the design. Many gliders are light and very stable making them an excellent choice for a beginner to learn to fly.

There are two basic ways for a glider to gain height once airborne and these are by thermal lift, and by slope lift.

Thermal Soaring
Thermal lift is created by areas of warm air rising from the land. As the land heats up with the warmth of the sun, the air above it Electric Powered Gliderwill begin to warm by the heat radiating from the land. Some of the best places to look for this type of lift are over freshly plowed field or a paved parking area. The heated air will begin to rise and allow cooler air to move in to replace it. This air, in turn, will heat up, rise, and you will get a continuous current of rising air. As long as the air is rising at a rate greater than a glider sinks while in flight, the glider can maintain lift.

Gliders designed for thermal soaring are usually of similar shape with long, slender wings for greater lift and a smooth narrow body for low drag. Many will have wings with polyhedral (a multiple dihedral) and the tail surfaces may take several forms such as a conventional tail, crusifix tail, T-tail, or V-tail.

Slope Soaring
Slope lift is generated by a breeze passing over the face of a cliff or sloping land . As the wind hits the vertical surface, PSS Nimrod - Maiden Flight!it has no where to go but up. As long as the upward movement of the air is greater than the sink rate of the glider, the craft will remain aloft. All classes of glider will work well in slope lift as there is usually more lift available and weight/wing loading is not as critical. Gliders designed for thermal soaring are better suited to light winds when slope soaring unless they can be ballasted for a higher wing loading. Slope aircraft are usually designed with shorter, swept wings, sleek fuselages, and are extremely fast and agile. Many designs look like jet aircraft. They can fly most aerobatic manoeuvres and will stay in the air as long as there's a breeze and you batteries hold out!

Launching a glider in slope lift is as simple as throwing the model out over the slope and straight into lift, however, launching for a thermal flight takes a bit more equipment. There are four basic ways of getting a thermal model into flight, a hi-start, a winch, a glow engine power pod and an electric motor.

Hi-Start or Bungee
The hi-start is basically a very long catapult. It is made of a length of surgical tubing (usually 50 to 100 feet) staked to the ground at one end and fastened to about four times as much nylon line (200 to 400 feet) at the other. A parachute/ring assembly on the end of the nylon line is clipped to a hook on the bottom of the glider on the centre of gravity. The tubing is streched to almost four times its length. When the pilot lets go of the model, it will soar at a very steep angle until the tubing has relaxed and the model is at peak altitude (anywhere from 250 to 400 feet). At that time, the line will drop off the hook and the parachute will guide the line back to the ground. As launches are always made into the wind, the parachute will float down carrying the line back toward the location of the launch. The hi-start is an excellent choice for the beginning sailplane pilot. Safety with the location of the stake is paramount and should be regularly checked to see that it is still well anchored in the ground. It should in any case be repositioned reularly.

The winch will launch a glider in a manner very similar to that of a hi-start, but the mechanism to do this is much more complicated and much more expensive. Winches are usually homemade and consist of an electric motor, powered by a 12 volt car battery, driving a drum onto which the nylon towline is wound. Again, a parachute is used for retrieval of the line. The motor is operated by a foot switch which is quite oftenswitched on and off by the operator so as not to overpower smaller gliders. The power of a winch is much greater than that of a hi-start and that is why it is more suitable for the larger models found in the "open class" type of gliders.

Power Pod
This method of glider launch is by glow engine power assist. This is a small engine mounted in a pod atop the center of gravity of the model. It is used to bring the model to altitude and then is shut off or runs out of fuel. This is a great way for getting to very high altitudes with your model but gliding performance will suffer with a pod mounted engine due to the extra drag.

Electric Motor
A fourth method, which has become very popular with the advancement in NiCd battery technology, is an electric motor launch. The electric motor is mounted in the nose of the aircraft and will usually have a folding prop which will fold back against the fuselage to reduce drag when the motor run has completed.

The motor is powered by a 6 or 7 cell rechargable NiCd and will run for between 3 and 5 minutes. If a separate motor control is used, the motor may be turned on and off during flight to regain altitude if lift is poor. The disadvantage of the electric motor launch is that the extra weight of the battery will increase wing loading and reduce the glide ratio.

What You Need To Get Started
The following is a list of the items will be required to get started with radio controlled gliders:

The Glider
Yes of course you need an aircraft, but which type? Just as with powered aircraft, there are some glider kits that are better suited to the beginner than others. A good choice would be something specially designed for beginners, requiring only 2 channels, usually rudder and elevator, a kit with a sturdy construction, and good building instructions. This type of aircraft is recommended regardless of whether you plan to thermal or slope soar.

Again, as with powered aircraft, you have the choice of building a model completely or just doing the final assembly of an Almost-Ready-to-Fly (ARTF) kit. Your choice should simply be driven by your desire to build. There are a few additional items you will need.

The Radio
Along with your aircraft, you will need a radio to control it. Most aircraft radio systems have four or more channel and come with just about everything you need including the rechargeable battery packs.
There are some radios available with special functions included that are usually with more sophisticated gliders. But these are not necessary for the beginning modeler.

Although your first glider will most likely only need two channels for rudder and elevator, you are still better off buying a four channel radio system. That is because all four channel systems usually come complete with rechargable batteries while the two channel systems do not. It is always safer to fly radio controlled model aircraft with rechargable NiCd batteries. Also, the stick configuration on 2 channel radios is more suitable for ground based vehicles than for aircraft. Also ensure that the radio is on the 35Mhz waveband and not anything else. This frequency band is specially designated to model aircraft in the UK. Please read ' Getting To Know R/C Radio Systems' for more information on the right radio to buy

Launching Equipment
If you plan to go slope soaring with your model, you will need virtaully no support equipment at all except for a few simple tools for minor repairs or adjustments. If you are planning to do some thermal soaring, your needs will vary depending upon which method you choose to get airbourne.

Launching with a Bungee
Launching with a bungee is probably the simplest and cleanest way to become airborne and is the most popular. The only item you will need is your hi-start. Theses come in various sizes and can be found at all good model shops.

Launching with a Glow Motor
Most 2-metre size gliders require a .049 to an .10 engine for power pod launch. For this you will require all the bits and pieces associated with powered flight including fuel, starting battery, wrench, and glow plug clip.

Launching with an Electric Motor
Many electric powered gliders come with the electric motor and prop assembly as part of the kit. The only additional items needed would be a battery (usually two, so you can fly while the other is on charge) and a fast charger that will operate from your 12V car battery while at the flying field.