Radio-controlled glider

A radio-controlled glider is a type of radio-controlled airplane that normally does not have any form of propulsion. They are able to sustain continuous flight by exploiting the lift produced by slopes and thermals, controlled remotely from the ground with a transmitter. They can be made from a variety of materials, including wood, plastic, polymer foams, and composites, and can vary in wing loading from very light to relatively heavy, depending on their use.

Launching a glider

Hand launch

Hand launching is the simplest way to get a model into the air. All the pilot needs to do is throw it horizontally, giving it sufficient speed. This method is usually combined with slope soaring, so the glider can gain altitude.

Towline launch

In this method another person runs along the ground, pulling a long (50 - 100m) piece of string with the glider attached to the end, while the pilot steers it. It can be performed on any flat piece of terrain, as the glider is given sufficient altitude during the launch.

Bungee launch

This launch is a variant of the towline launch performed alone. The running person is replaced by a piece of elastic band attached to the ground.

'Piggyback' launch

A powerful radio-controlled airplane tows the model glider into the air, rather like real gliders are launched. Although this method is spectacular, it requires a very experienced pilot to steer the towing airplane.

Discus launch

This way of launching can be performed only on a special type of glider - a DLG (Discus Launch Glider (DLG), Radio Controlled). To launch the model into the air, the pilot holds the model by the tip of a wing, spins 360°, rotating the model around his/her body and then releases hold of the model allowing it to launch at high speed . Although DLGs are a fairly new type of gliders, they are gaining popularity due to their ease of launching and efficient flight characteristics. DLG models are used in the F3K contest class, as defined by FAI.

Forms of flight

lope soaring

Slope soaring uses the lift produced by wind blowing up the face of a steep slope on hills, mountains, and cliffs. Dynamic soaring, utilizing the leeward or "backside" of a hill, has recently become very popular.

Dynamic soaring

Dynamic soaring is a relatively new style of flying model gliders whereby the windshear just downwind of certain slopes can be used to create high speeds. It involves gaining altitude, then soaring into a patch of dead air, then back to the lift to gain speed.

Thermal soaring

Thermal soaring uses columns of warm, rising air called thermals to provide lift for a glider. They are normally launched with a bungee cord catapult, a winch, towed by a powered plane. A discus launch glider (DLG) is simply catapulted into the air with a spinning motion much like a discus throw.

Discus launching is often combined with slope soaring. Thermals from elsewhere can drift in over the hill to combine with the hill lift or they can be formed by the hill itself, if the slope is angled to the sun causing the slope to heat up faster than in the surrounding areas. The resulting warm air will then flow upwards pulling in air from the valley below, causing a wind up the slope. The lift is thus a combination of ridge lift and thermal. This has produced new term, "slermal", to describe the mixture of both slope lift and thermal activity coming up the hill face.

Activities

Combat

Combat is usually flown with expanded polypropylene (EPP) [http://RCSkyFlyer.com] ) models due to their impact resistance. Each pilot tries to knock the other's aircraft physically out of the air. A "kill" is scored only when the opponents aircraft hits the ground. If a hit occurs and each aircraft recovers and remains airborne, the hits generally do not count. Often this activity includes extreme manoeuvres and aerobatics.

This particular class of slope glider is extremely popular, as novices can learn to fly with a model that is practically indestructible. There is also a wide appeal in owning an inexpensive glider that is also a stand-off scale model, particularly of favourite World War II fighters, e.g. the Spitfire/Seafire, P-51 Mustang, P-47 Thunderbolt.

As of the time of writing, model EPP Jet Fighter Slope Soarers have become extremely popular, usually either 1950s and some 1960s designs e.g. the MiG-15, the P-80 Shooting Star, and the F-86 Sabre, and the Northrop F-5 and F-20.More ambitious modellers are experimenting with more recent jet fighters such as the F-16, F-15, MiG-29 and Su-27.

Equally popular are models of military trainers, such as the Pilatus PC-9, BAe Hawk, and Aermacchi MB 326 and MB 339.

Ridge racing

Ridge racing (or pylon racing where markers are present) is essentially using the slope lift to race along the "lift zone" -- generally parallel to the slope. This can be MoM (man-on-man) racing, in which 2 to 4 planes compete against each other on the same course. Scoring is similar to match racing in the sport of sailing - the first pilot to complete the course receives one point, the second two points and so on. At the end of the competition, the pilot with the fewest points wins. Another form of slope r/c glider racing is called F3F. F3F is one of many competition categories for model and full scale aircraft that are defined by the Fédération Aéronautique Internationale (FAI). In F3F racing, the pilot is timed on the course for 10 legs of 100 meters for a total distance of 1 kilometer. All pilots fly a timed run for each round. The fastest pilot receives 1000 points for the round and all others are given a percentage which is determined by the ratio of their time to the fast time for the round. At the end of the competition, the pilot with the most points wins.

Type

Flying wings

Expanded polypropylene (EPP) [http://RCSkyFlyer.com] ) flying wings have become very popular recently, primarily due to their strength. The Zagi is a very popular flying wing. They are often used for slope combat, where pilots try to knock other pilots' gliders out of the sky with their own.

cale gliders

Scale gliders are models of full size gliders. Scale gliders are generally larger models (2m wingspan or greater) and made from composite materials.

PSS

PSS, or power scale soaring, is all about building and flying scale model gliders of full sized jet, rocket or piston powered aircraft. World War II prop planes such as the P-51, Supermarine Spitfire and Me 109 are common subjects for PSS planes, however PSS aircraft produced to date have ranged from the early bi-planes through to modern jet fighters and even commercial airliners.

The challenge with Power Scale Soaring is to build a model as close to scale as possible whilst at the same time ensuring the model has good flying characteristics.

For more information about Power Scale Soaring and to see examples of PSS models please visit the [http://www.pssaonline.co.uk Power Scale Soaring Association]

Powered gliders

Powered gliders use electric motors, internal combustion engines or even jet turbines to provide propulsion for a glider to get in the air. They are normally used to get thermal soarers in the air.

Beginners Guide to Radio Controlled Gliding

For an introduction to getting started in this hobby please visit [http://www.rcgliding.co.uk this beginners guide]

Instructional DVDs on R/C Gliding

Expert Paul Naton produces many instructional DVDs on the sport of R/C soaring [http://www.radiocarbonart.com so visit his excellent web site.]

ee also

* Radio-controlled model
* Gliding