Radio-controlled glider
Encyclopedia
A radio-controlled glider is a type of radio-controlled aircraft
Radio-controlled aircraft
A radio-controlled aircraft is controlled remotely by a hand-held transmitter and a receiver within the craft...

 that normally does not have any form of propulsion. They are able to sustain continuous flight by exploiting the lift produced by slopes and thermal
Thermal
A thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...

s, controlled remotely from the ground with a transmitter
Transmitter
In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...

. They can be constructed from a variety of materials, including wood, plastic, polymer foam
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...

s, and composites
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...

, and can vary in wing loading
Wing loading
In aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing. The faster an aircraft flies, the more lift is produced by each unit area of wing, so a smaller wing can carry the same weight in level flight, operating at a higher wing loading. Correspondingly,...

 from very light to relatively heavy, depending on their intended use.

International radio-controlled glider competitions are regulated by the Fédération Aéronautique Internationale
Fédération Aéronautique Internationale
The Fédération Aéronautique Internationale is the world governing body for air sports and aeronautics and astronautics world records. Its head office is in Lausanne, Switzerland. This includes man-carrying aerospace vehicles from balloons to spacecraft, and unmanned aerial vehicles...

 (FAI) although many countries have their own national classes.

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) line 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. A variation of this method uses a pulley staked to the ground with the tower moving toward the pilot.

Bungee/Hi-start launch

This launch is a variant of the towline launch performed alone. The running person is replaced by a combined length of elastic cord or rubber tubing and line which is attached to the ground, often using a 'corkscrew' dog stake.

'Piggyback' launch

A second, powered radio-controlled powered aircraft lifts the model glider into the air, attached to a special cradle which is, in turn, mounted to either the top or the bottom of the carrier aircraft. Although this method is spectacular, it requires an experienced pilot to steer the carrier aircraft as the addition of the glider can significantly affect the handling of the carrier aircraft. Special care must be also taken by the pilots of both models to avoid a collision after the release of the glider.

Discus launch

This method of launching can be performed only on a special type of glider - a Discus Launch Glider. 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.

Aerotow launch

As full-size aerotowing using a radio-controlled tug, often used for launching larger scale gliders.

Winch launch

As full-size winch launching but using a small electric motor and a reverse pulley staked to the ground. The launch speed is controlled by the pilot using a foot pedal.

Slope soaring

Slope soaring uses the lift produced by wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

 blowing up the face of a steep slope on hill
Hill
A hill is a landform that extends above the surrounding terrain. Hills often have a distinct summit, although in areas with scarp/dip topography a hill may refer to a particular section of flat terrain without a massive summit A hill is a landform that extends above the surrounding terrain. Hills...

s, mountain
Mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...

s, and cliff
Cliff
In geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually...

s. Dynamic soaring
Dynamic soaring
Dynamic soaring is a flying technique used to gain energy by repeatedly crossing the boundary between air masses of significantly different velocity...

, utilizing the leeward or "backside" of a hill, has recently become very popular.
Combat

Combat is usually flown with expanded polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...

 (EPP) foam 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 maneuvers and aerobatics
Aerobatics
Aerobatics is the practice of flying maneuvers involving aircraft attitudes that are not used in normal flight. Aerobatics are performed in airplanes and gliders for training, recreation, entertainment and sport...

.

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 favorite World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 fighters, e.g. the Spitfire
Supermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and many other Allied countries throughout the Second World War. The Spitfire continued to be used as a front line fighter and in secondary roles into the 1950s...

/Seafire
Supermarine Seafire
The Supermarine Seafire was a naval version of the Supermarine Spitfire specially adapted for operation from aircraft carriers. The name Seafire was arrived at by collapsing the longer name Sea Spitfire.-Origins of the Seafire:...

, P-51 Mustang
P-51 Mustang
The North American Aviation P-51 Mustang was an American long-range, single-seat fighter and fighter-bomber used during World War II, the Korean War and in several other conflicts...

 and P-47 Thunderbolt
P-47 Thunderbolt
Republic Aviation's P-47 Thunderbolt, also known as the "Jug", was the largest, heaviest, and most expensive fighter aircraft in history to be powered by a single reciprocating engine. It was heavily armed with eight .50-caliber machine guns, four per wing. When fully loaded, the P-47 weighed up to...

.
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 gliders 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
Fédération Aéronautique Internationale
The Fédération Aéronautique Internationale is the world governing body for air sports and aeronautics and astronautics world records. Its head office is in Lausanne, Switzerland. This includes man-carrying aerospace vehicles from balloons to spacecraft, and unmanned aerial vehicles...

 (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.
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
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 prop planes such as the P-51, Supermarine Spitfire
Supermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and many other Allied countries throughout the Second World War. The Spitfire continued to be used as a front line fighter and in secondary roles into the 1950s...

 and Me 109 are common subjects for PSS planes, however PSS aircraft produced to date have ranged from the early biplanes through to modern jet fighters and even commercial airliner
Airliner
An airliner is a large fixed-wing aircraft for transporting passengers and cargo. Such aircraft are operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an aircraft intended for carrying multiple passengers in commercial...

s.

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.

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
P-80 Shooting Star
The Lockheed P-80 Shooting Star was the first jet fighter used operationally by the United States Army Air Forces. Designed in 1943 as a response to the German Messerschmitt Me-262 jet fighter, and delivered in just 143 days from the start of the design process, production models were flying but...

, and the F-86 Sabre
F-86 Sabre
The North American F-86 Sabre was a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as America's first swept wing fighter which could counter the similarly-winged Soviet MiG-15 in high speed dogfights over the skies of the Korean War...

, and the Northrop F-5 and F-20
F-20 Tigershark
The Northrop F-20 Tigershark was a privately-financed light fighter, designed and built by Northrop. Its development began in 1975 as a further evolution of Northrop's F-5E Tiger II, featuring a new engine that greatly improved overall performance, and a modern avionics suite including a powerful...

.
More ambitious modellers are experimenting with more recent jet fighters such as the F-16
F-16 Fighting Falcon
The General Dynamics F-16 Fighting Falcon is a multirole jet fighter aircraft originally developed by General Dynamics for the United States Air Force . Designed as an air superiority day fighter, it evolved into a successful all-weather multirole aircraft. Over 4,400 aircraft have been built since...

, F-15
F-15 Eagle
The McDonnell Douglas F-15 Eagle is a twin-engine, all-weather tactical fighter designed by McDonnell Douglas to gain and maintain air superiority in aerial combat. It is considered among the most successful modern fighters with over 100 aerial combat victories with no losses in dogfights...

, MiG-29 and Su-27.

Equally popular are models of military trainers, such as the Pilatus
Pilatus
Pilatus may refer to:* Pilatus , a mountain in Switzerland* Pilatus , an X-ray area detector developed at the Swiss Light Source* Pilatus , a 1917 play by Kaj Munk manufacturer* Pilatus Aircraft, a Swiss aircraft manufacturer...

 PC-9, BAe Hawk
BAE Hawk
The BAE Systems Hawk is a British single-engine, advanced jet trainer aircraft. It first flew in 1974 as the Hawker Siddeley Hawk. The Hawk is used by the Royal Air Force, and other air forces, as either a trainer or a low-cost combat aircraft...

, and Aermacchi
Aermacchi
Alenia Aermacchi is an Italian company designing and producing trainer aircraft for military pilots.-Profile:Alenia Aermacchi has sold about 2,000 trainers to more than 40 countries and has collaborated in major international military programs....

 MB 326 and MB 339.

More information about Power Scale Soaring can be found under Power Scale Soaring Association
Power Scale Soaring Association
Power Scale Soaring, or PSS is a fast growing dimension in Radio Controlled model slope soaring. PSS is all about building and flying scale model gliders of full-sized jet, rocket or piston powered aircraft....

 and the website of the Power Scale Soaring Association (PSSA)http://www.pssaonline.co.uk/main-pages/history%20of%20the%20pssa.htm
Dynamic soaring


Dynamic soaring is a relatively new style of flying model gliders whereby the windshear
WindShear
The Windshear Full Scale Rolling Road Wind Tunnel is an automotive wind tunnel in Concord, North Carolina.In January 2008 Wind Shear, a division of US machine tool builder Haas Automat-80.7ion, completed construction on one of the most advanced automotive wind tunnels in the world. The full-scale...

 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 thermal
Thermal
A thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...

s to provide lift for a glider. Thermal soaring gliders are normally launched with a bungee cord
Bungee cord
A bungee cord , also known as a shock cord, is an elastic cord composed of one or more elastic strands forming a core, usually covered in a woven cotton or polypropylene sheath...

 catapult, a winch
Winch
A winch is a mechanical device that is used to pull in or let out or otherwise adjust the "tension" of a rope or wire rope . In its simplest form it consists of a spool and attached hand crank. In larger forms, winches stand at the heart of machines as diverse as tow trucks, steam shovels and...

 or towed by a powered plane. A discus launch glider (DLG)
Discus Launch Glider (DLG), Radio Controlled
A Discus Launch Glider is a radio controlled model sailplane launched using a 'discus launch' in which the glider is held by a wingtip and rotated around the flyer by hand before release...

 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
Anabatic wind
An anabatic wind, from the Greek anabatos, verbal of anabainein meaning moving upward, is a wind which blows up a steep slope or mountain side, driven by heating of the slope through insolation. It is also known as an upslope flow. These winds typically occur during the daytime in calm sunny weather...

, 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 a new term, "slermal", to describe the mixture of both slope lift and thermal activity coming up the hill face.

Flying wings

Expanded polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...

 foam ( EPP) foam flying wing
Flying wing
A flying wing is a tailless fixed-wing aircraft which has no definite fuselage, with most of the crew, payload and equipment being housed inside the main wing structure....

s have become very popular recently, primarily due to their crash damage resistance and low cost. They are often used for slope combat, where pilots try to knock other pilots' gliders out of the sky with their own. A "kill" is only scored when the opponent's plane actually hits the ground. A popular airfoil used on some flying wing type gliders is the KF airfoil or one of the variants of the family of the Kline Fogleman airfoil
Kline Fogleman airfoil
The Kline–Fogleman airfoil or KF Airfoil is an airfoil design with single or multiple steps induced along the length of the wing.- Kline–Fogleman airfoil :...

. This airfoil has been proven to show an increase in performance by providing greater stability on the wing at lower speeds.

Scale gliders

Scale
Scale model
A scale model is a physical model, a representation or copy of an object that is larger or smaller than the actual size of the object, which seeks to maintain the relative proportions of the physical size of the original object. Very often the scale model is used as a guide to making the object in...

 gliders are models of full-size gliders. Scale gliders are generally larger models (2 m wingspan or greater) and made from composite materials. Scale Gliders are sometimes modified slightly to obtain the best flying characteristics, such as less drag and more aerobatic potential. This is achieved by changing the size of the control surfaces or the wing airfoil. Some scale gliders are very close in appearance to their full scale counterparts, and this makes them a beautiful sight at any flying field. A model often "scaled" because of its clean looks and great aerobatic potential is the MDM-1 Fox. The ASW series (mostly ASW-26 and ASW-28) are also popular scale gliders.

Powered gliders

Powered gliders use electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...

s, internal combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

s 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. Some electric gliders have propellers which fold inwards when the power source is cut of during flight. This provides the glider with lower air resistance and reduces overall drag which may be present if the propeller was to remain in its open or natural state.

International

International radio-controlled glider competitions are regulated by the Fédération Aéronautique Internationale
Fédération Aéronautique Internationale
The Fédération Aéronautique Internationale is the world governing body for air sports and aeronautics and astronautics world records. Its head office is in Lausanne, Switzerland. This includes man-carrying aerospace vehicles from balloons to spacecraft, and unmanned aerial vehicles...

(FAI). The classes are:
  • F3B - Multi-task soaring, no model limitations.
  • F3F - Slope speed (pylon racing), no model limitations.
  • F3H - Cross country soaring racing
  • F3J - Thermal duration soaring, no model limitations. 150 m towline maximum length.
  • F3K - Handlaunched glider
  • F5B - Electric soaring, wing loading and maximum battery weight limitations apply.

United Kingdom

British national radio-controlled glider classes are:
  • Mini-glider - Maximum wingspan 60 inches, maximum weight 22 ounces.
  • Two metre - Maximum wingspan two metres, 150 m towline maximum length.
  • 100S or Standard Class Maximum wingspan 100 inches (thermal soaring). 150 m towline maximum length.
  • BARCS Open Class - No model limitations, 150 m hand towline only.
  • Sixty inch slope - Pylon racing, maximum wingspan 60 inches
  • Slope cross country - No model limitations, pilot walks around a course while controlling the model.
  • PSS and Scale - The model must be a recognisable replica of a full-size powered aircraft or glider.
  • Slope aerobatics - No model limitations.
  • E-slot - Maximum seven-cell battery pack
  • Electroslot E400 Motor must be standard 'Speed 400' type.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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