Radio-controlled aircraft
Overview
 
A radio-controlled
Radio control
Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...

 (model) aircraft
Model aircraft
Model aircraft are flying or non-flying models of existing or imaginary aircraft using a variety of materials including plastic, diecast metal, polystyrene, balsa wood, foam and fibreglass...

(often called RC aircraft or RC plane) is controlled remotely by a hand-held 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...

 and a receiver
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...

 within the craft. The receiver controls the corresponding servo
Servomechanism
thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...

s that move the control surfaces based on the position of joysticks on the transmitter, which in turn affect the orientation of the plane.

Flying RC aircraft as a hobby
Hobby
A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...

 has been growing worldwide with the advent of more efficient motors (both electric
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...

 and miniature internal combustion or jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...

s), lighter and more powerful batteries
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

 and less expensive radio systems. A wide variety of models and styles is available.

Scientific, government and military organizations are also utilizing RC aircraft for experiments, gathering weather readings, aerodynamic
Aerodynamics
Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

 modeling and testing, and even using them as drone
Unmanned aerial vehicle
An unmanned aerial vehicle , also known as a unmanned aircraft system , remotely piloted aircraft or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously, that is, as a self-directing entity...

s or spy planes.
The earliest examples of electronically guided model aircraft were hydrogen-filled model airship
Airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

s of the late 19th century.
Encyclopedia
A radio-controlled
Radio control
Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...

 (model) aircraft
Model aircraft
Model aircraft are flying or non-flying models of existing or imaginary aircraft using a variety of materials including plastic, diecast metal, polystyrene, balsa wood, foam and fibreglass...

(often called RC aircraft or RC plane) is controlled remotely by a hand-held 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...

 and a receiver
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...

 within the craft. The receiver controls the corresponding servo
Servomechanism
thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...

s that move the control surfaces based on the position of joysticks on the transmitter, which in turn affect the orientation of the plane.

Flying RC aircraft as a hobby
Hobby
A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...

 has been growing worldwide with the advent of more efficient motors (both electric
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...

 and miniature internal combustion or jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...

s), lighter and more powerful batteries
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

 and less expensive radio systems. A wide variety of models and styles is available.

Scientific, government and military organizations are also utilizing RC aircraft for experiments, gathering weather readings, aerodynamic
Aerodynamics
Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

 modeling and testing, and even using them as drone
Unmanned aerial vehicle
An unmanned aerial vehicle , also known as a unmanned aircraft system , remotely piloted aircraft or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously, that is, as a self-directing entity...

s or spy planes.

History

The earliest examples of electronically guided model aircraft were hydrogen-filled model airship
Airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

s of the late 19th century. They were flown as a music hall act around theater auditoriums using a basic form of spark-emitted radio signal. In 1920s, the Royal Aircraft Establishment
Royal Aircraft Establishment
The Royal Aircraft Establishment , was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence , before finally losing its identity in mergers with other institutions.The first site was at Farnborough...

 of Britain built and tested the Larynx, a monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...

 with a 100 miles (160.9 km) range powered by a Lynx engine. It was not until the 1930s that the British came up with the Queen Bee, a modified de Havilland Tiger Moth
De Havilland Tiger Moth
The de Havilland DH 82 Tiger Moth is a 1930s biplane designed by Geoffrey de Havilland and was operated by the Royal Air Force and others as a primary trainer. The Tiger Moth remained in service with the RAF until replaced by the de Havilland Chipmunk in 1952, when many of the surplus aircraft...

, and similar target aircraft.

Types

There are many types of radio-controlled aircraft. For beginning hobbyists, there are park flyer
Park flyer
thumb|250px|This [[Grand Wing Servo-Tech]] [[GWS Slow Stick|Slow Stick]] is an example of an indoor/outdoor park flyerThe term park flyer denotes a class of small, primarily electric powered radio controlled aircraft, so named because their size enables some of them to be operated within the...

s and trainer
Trainer (aircraft)
A trainer is a class of aircraft designed specifically to facilitate in-flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristics and a simplified cockpit arrangement—allows...

s. For more advanced pilots there are glow plug
Glow plug (model engine)
A glow plug is a device, similar to a spark plug, used to help ignite the fuel in the very small internal combustion engines typically used in model aircraft, model cars and similar applications...

 engine, electric powered and sailplane aircraft. For expert flyers, jets, pylon racers, helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s, autogyro
Autogyro
An autogyro , also known as gyroplane, gyrocopter, or rotaplane, is a type of rotorcraft which uses an unpowered rotor in autorotation to develop lift, and an engine-powered propeller, similar to that of a fixed-wing aircraft, to provide thrust...

s, 3D aircraft, and other high-end competition aircraft provide adequate challenge. Some models are made to look and operate like a bird instead. Replicating historic and little known types and makes of full-size aircraft as "flying scale" models, which are also possible with control line
Control line
Control line is a simple and light way of controlling a flying model aircraft. The aircraft is connected to the operator by a pair of lines, attached to a handle, that work the elevator of the model. This allows the model to be controlled in the pitch axis...

 and free flight
Free flight (model aircraft)
The segment of model aviation known as free flight is the original form of the aeromodeling hobby, extending back centuries.- Description :...

 types of model aircraft, actually reach their maximum realism and behavior when built for radio control flying.

Radio control scale aircraft modeling

Perhaps the most realistic form of aeromodeling, in its main purpose to replicate full-scale aircraft designs from aviation history, for testing of future aviation designs, or even to realize never-built "proposed" aircraft, is that of radio control scale aeromodeling. RC Scale model aircraft can be of any type of steerable airship
Airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

 lighter-than-air (LTA) aviation craft, or more normally, of the heavier-than-air fixed wing glider/sailplane, fixed-wing single or multi-engine aircraft, or rotary-wing aircraft such as autogyros or helicopters.

Full-scale aircraft designs from every era of aviation, from the "Pioneer Era" up to World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

's start, through to the modern day in the 21st century, have been modeled as radio control scale model aircraft. Builders of RC Scale aircraft can enjoy the challenge of creating a controllable, miniature aircraft that merely "looks" like the full scale original in the air with no "fine details", such as a detailed cockpit, or go into seriously replicating many operable features of a selected full scale aircraft design, even down to having operable cable-connected flight control surfaces, illuminated navigation lighting on the aircraft's exterior, realistically retracting landing gear, etc. if the full-sized aircraft possessed such features as part of its design.

Various scale sizes of RC scale aircraft have been built in the decades since modern digital-proportional, miniaturized RC gear came on the market in the 1960s, and everything from indoor-flyable electric powered RC Scale models, to enormous "giant scale" RC Scale models, in scale size ranges that usually run from 20% to 25%, and upwards to 30 to 50% size of some smaller full scale aircraft designs, that can amazingly replicate some of the actual flight characteristics of the full scale aircraft they are based on, have been enjoyed, and continue to be built and flown, in sanctioned competition and for personal pleasure, as part of the RC scale aeromodeling hobby.

Sailplanes and gliders

Gliders
Glider (sailplane)
A glider or sailplane is a type of glider aircraft used in the sport of gliding. Some gliders, known as motor gliders are used for gliding and soaring as well, but have engines which can, in some cases, be used for take-off or for extending a flight...

 are planes that do not typically have any type of propulsion, as a general rule. Because most gliders are unpowered, flight must be sustained through exploitation of the natural lift produced from 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 or 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...

 hitting a slope. 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...

 is another popular way of providing energy to gliders that is becoming more and more common.

Jets

Jet
Jet aircraft
A jet aircraft is an aircraft propelled by jet engines. Jet aircraft generally fly much faster than propeller-powered aircraft and at higher altitudes – as high as . At these altitudes, jet engines achieve maximum efficiency over long distances. The engines in propeller-powered aircraft...

s tend to be very expensive and commonly use a micro turbine or ducted fan
Ducted fan
A ducted fan is a propulsion arrangement whereby a fan, which is a type of propeller, is mounted within a cylindrical shroud or duct. The duct reduces losses in thrust from the tip vortices of the fan, and varying the cross-section of the duct allows the designer to advantageously affect the...

 to power them. Most airframes are constructed from fiber glass and carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...

. Inside the aircraft, wooden spars reinforce the body to make a rigid airframe . They also have kevlar fuel tanks for the Jet A fuel that they run on. Most micro turbines start with propane, burn for a few seconds before introducing the jet fuel by solenoid. These aircraft can often reach speeds in excess of 320 km/h (200 mph). They require incredibly quick reflexes and very expensive equipment, so are usually reserved for the expert. The FAA heavily regulates flying of such aircraft to only approved AMA Academy of Model Aeronautics
Academy of Model Aeronautics
The Academy of Model Aeronautics, based in Muncie, Indiana, USA, is a non-profit organization dedicated to the promotion of model aviation as a recognized sport as well as a recreational activity. It is the largest organization of its kind with a current membership of more than 170,000...

 sites, in where certified turbine pilots may fly. Also, the AMA requires model aviation enthusiasts who wish to operate miniature gas turbine powered RC model aircraft, to be certified in the operation of the type of gas turbine engine, and all aspects of safety in operating such a turbine-powered model aircraft, that they need to know in flying their model.http://www.modelaircraft.org/files/510-d.pdf. Some military bases allow such high tech aircraft to fly within limited airspace such as Kaneohe Marine base in Hawaii, and Whidbey Island NAS in Washington State. An average turbine aircraft will cost between $150–$10,000 with more than $20,000 all-up becoming more common. Many manufactures sell airframes such as Yellow Aircraft and Skymaster. Turbines are produced from The Netherlands (AMT)to Mexico (Artes Jets). The average microturbine will cost between $2500 and $5000 depending on engine output. Smaller turbines put out about 12 lbf
Pound-force
The pound force is a unit of force in some systems of measurement including English engineering units and British gravitational units.- Definitions :...

 (53 N) of thrust, while larger microturbines can put out as much as 45 lbf (200 N) of thrust. Radio control jets require an on board FADEC (Full Authority Digital Engine Control) controller, this controls the turbine, just like a larger turbine. RC Jets also require electrical power. Most have a LIPO (Lithium Polymer pack) at 8-12 volts that control the FADEC. There is also a LIPO for the onboard servos that control ailerons, elevator, rudder, flaps and landing gear.

Of much less complexity are the types of RC jet aircraft that actually use an electric motor-driven ducted fan
Ducted fan
A ducted fan is a propulsion arrangement whereby a fan, which is a type of propeller, is mounted within a cylindrical shroud or duct. The duct reduces losses in thrust from the tip vortices of the fan, and varying the cross-section of the duct allows the designer to advantageously affect the...

 instead to power the aircraft. So called "EDF" models can be of much smaller size, and only need the same electronic speed contoller and rechargeable battery technology as propeller-driven RC electric powered aircraft use.

Pylon racers

Racers are small propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...

-driven aircraft that race around a 2, 3, or 4 pylon track. They tend to be hard to see and can often go over 240 kilometre per hour, though some people do pylon races with much slower aircraft. Although several different types of aircraft are raced across the world, those flown primarily in the US are; Q500 (424 or ARPRA, and 428), and Q40.
424 is designed as a starting point into the world of pylon racing. Inexpensive (under $200 for the airframe) kits with wing areas of 3200 square centimetres (496 sq in) are flown with .40 size engines that can be purchased for less than $100. The goal is for the planes to be not only inexpensive, but closely matched in performance. This places the emphasis on good piloting. APRA is a version of 424 with specific rules designed for consistency.
428 aircraft are similar to 424 in appearance. The difference is in engine performance and construction. The planes are primarily made of fiberglass with composites used at high load points. Wings are often hollow to save weight. (All aircraft must meet a minimum weight. A lighter wing moves more of the weight closer to the center of gravity. This requires less control deflection and its resulting drag to change the planes attitude.) They also use .40 cu in size engines but unlike 424 they are much more expensive. They have been designed to put out the maximum amount of power at a specific RPM using a specific fuel. Nelson manufactures the most predominantly used engine. Speeds are very fast in this class with planes capable of reaching 290 kilometre per hour.
Q40 is the highpoint of pylon racing, as their aircraft resemble full-size race planes. They are not limited to the simple shapes that Q500 planes are, which have much cleaner aerodynamics and less wing area. They use the same basic Nelson engine used in 428, but the engine is tuned to turn a much smaller prop at a much higher rpm. The planes accelerate much more slowly than 428, but their clean airframes allow them to reach higher speeds, and maintain them around the turns. These planes can fly in excess of 320 kilometre per hour on the course. Because of their limited wing area however, Q40 planes must fly a larger arc around the pylons to conserve energy. Although faster, they ultimately fly a larger course. Ironically the best times for a 10 lap 3 pylon Q40 race are very close to the same in 428.

Helicopters


Radio-controlled helicopter
Radio-controlled helicopter
Radio-controlled helicopters are model aircraft which are distinct from RC airplanes because of the differences in construction, aerodynamics, and flight training...

s, although often grouped with RC aircraft, are in a class of their own because of the vast differences in construction, aerodynamics and flight training
Flight training
Flight training is a course of study used when learning to pilot an aircraft. The overall purpose of primary and intermediate flight training is the acquisition and honing of basic airmanship skills....

. Hobbyists will often venture from planes, to jets and to helicopters as they enjoy the challenges, excitement and satisfaction of flying. Some radio-controlled helicopters have photo or video cameras installed and are used for aerial imaging or surveillance. Newer "3d" radio control helicopters can fly inverted with the advent of advanced swash heads, and servo linkage that enables the pilot to immediately reverse the pitch of the blades, creating a reverse in thrust.

Flying bird models, or ornithopters

Some RC models take their inspiration from nature. These may be gliders made to look like a real bird, but more often they actually fly by flapping wings
Ornithopter
An ornithopter is an aircraft that flies by flapping its wings. Designers seek to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, they are usually built on the same scale as these flying creatures. Manned ornithopters have also been built, and some...

. Spectators are often surprised to see that such a model can really fly. These factors as well as the added building challenge add to the enjoyment of flying bird models, though some ARF (almost-ready-to-fly
Almost Ready to Fly
Almost Ready to Fly is a term used for radio-controlled airplane kits that come partially built, usually just requiring final assembly to complete them. They normally include partially assembled wings, along with a fuselage and stabilizers already pre-covered in plastic film sheeting material such...

) models are available. Flapping-wing models are also known as ornithopter
Ornithopter
An ornithopter is an aircraft that flies by flapping its wings. Designers seek to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, they are usually built on the same scale as these flying creatures. Manned ornithopters have also been built, and some...

s, the technical name for an aircraft whose driving airfoils oscillate instead of rotate.

Toy-class RC

Since about 2004, new, more sophisticated toy RC airplanes, helicopters, and ornithopters have been appearing on toy store shelves. This new category of toy RC distinguishes itself by:
  • Proportional (vs. "on-off") throttle control which is critical for preventing the excitation of phugoid
    Phugoid
    A phugoid or fugoid is an aircraft motion where the vehicle pitches up and climbs, and then pitches down and descends, accompanied by speeding up and slowing down as it goes "uphill" and "downhill." This is one of the basic flight dynamics modes of an aircraft , and a classic example of a positive...

     oscillation ("porpoising") whenever a throttle change is made. It also allows for manageable and steady altitude control and reduction of altitude loss in turns.
  • Lithium polymer batteries for light weight and long flight time.
  • EPP (Expanded Polypropylene)
    EPP
    -Organisations:* Engineering and Public Policy, an academic department at Carnegie Mellon University* European People's Party, a European political party* European People's Party * European Public Prosecutor, a proposed EU agency...

     foam construction making them "indestructible" in normal crash-prone use.
  • Low flying speed and typically rear-mounted propeller(s) make them harmless when crashing into people and property.
  • Stable spiral mode resulting in simple turning control where "rudder" input results in a steady bank angle rather than a steady roll rate.


As of 2009, the toy class RC airplane typically has no elevator control. This is to manage costs, but it also allows for simplicity of control by unsophisticated users of all ages. The down side of lack of elevator control is a tendency for the airplane to phugoid
Phugoid
A phugoid or fugoid is an aircraft motion where the vehicle pitches up and climbs, and then pitches down and descends, accompanied by speeding up and slowing down as it goes "uphill" and "downhill." This is one of the basic flight dynamics modes of an aircraft , and a classic example of a positive...

. To damp the phugoid oscillation naturally, the planes are designed with high drag which reduces flight performance and flying time. The lack of elevator control also prevents the ability to "pull back" during turns to prevent altitude loss and speed increase.

Costs range from 20 to 40 USD. Crashes are common and inconsequential. Throttle control and turning reversal (when flying toward the pilot) rapidly become second-nature, giving a significant advantage when learning to fly a more costly hobby class RC aircraft.

3D flight

3D flight is a type of flying in which model aircraft have a thrust-to-weight ratio
Thrust-to-weight ratio
Thrust-to-weight ratio is a ratio of thrust to weight of a rocket, jet engine, propeller engine, or a vehicle propelled by such an engine. It is a dimensionless quantity and is an indicator of the performance of the engine or vehicle....

 of more than 1:1 (typically 1.5:1 or more), large control surfaces with extreme throws, low weight compared to other models of same size and relatively low wing loadings.

These elements allow for spectacular aerobatics such as hovering, 'harriers', torque rolling, blenders, rolling circles, and more, maneuvers that are performed below the stall speed of the model. The type of flying could be referred to as 'on the prop' as opposed to 'on the wing', which would describe more conventional flight patterns that make more use of the lifting surfaces of the plane.

3D has created a huge market for electric indoor 'profile' types similar to the Ikarus 'Shockflyers' designed to be able to fly inside a gym or outside in little wind. These generally make use of small brushless motors
Brushless DC electric motor
Brushless DC motors also known as electronically commutated motors are electric motors powered by direct-current electricity and having electronic commutation systems, rather than mechanical commutators and brushes...

 (often outrunners, but also geared inrunners) and lithium polymer batteries
Lithium ion polymer battery
Lithium-ion polymer batteries, polymer lithium ion, or more commonly lithium polymer batteries are rechargeable batteries...

. There are also many larger 3D designs designed for two and four stroke glow engines, two stroke gas engines and large electric power systems. The most common and which most pilots describe as the best size of a 3D plane is a 40%/150cc class.

Video piloting (first-person view)

First-person view (FPV) flight is a type of remote-control flying that has grown in popularity in recent years. It involves mounting a small video camera and analog television transmitter on an RC aircraft and flying by means of a live video down-link, commonly displayed on video goggles or a portable LCD screen. When flying FPV, the pilot sees from the aircraft's perspective, and does not even have to look at the model. As a result, FPV aircraft can be flown well beyond visual range, limited only by the range of the remote control and video transmitter. Video transmitters typically operate at a power level between 200 mW and 1500 mW. The most common frequencies used for video transmission are 900 MHz, 1.2 GHz, 2.4 GHz, and 5.8 GHz. Specialized long-range UHF control systems operating at 433 MHz or 869 MHz are commonly used to achieve greater control range, while the use of directional, high-gain antennas increases video range. Sophisticated setups are capable of achieving a range of 20-30 miles or more.

A basic FPV system consists of a camera, video transmitter, video receiver, and a display. More advanced setups commonly add in specialized hardware, including on-screen displays with GPS navigation and flight data, stabilization systems, and autopilot devices with "return to home" capability--allowing the aircraft to fly back to its starting point on its own in the event of signal loss. On-board cameras can be equipped with a pan
PAN
Pan and panning can have many meanings as listed below in various categories.-Prefix:* Pan- as a prefix , e.g.:** Pan American** Pan-Americanism...

 and tilt mount, which when coupled with video goggles and "head tracking" devices creates a truly immersive, first-person experience, as if the pilot was actually sitting in the cockpit of the RC aircraft.

Both helicopters and fixed-wing RC aircraft are used for FPV flight. The most commonly chosen airframes for FPV planes are larger models with sufficient payload space for the video equipment and large wings capable of supporting the extra weight. Pusher-propeller planes are preferred so that the propeller is not in view of the camera. "Flying wing" designs are also popular for FPV, as they provide the best combination of large wing surface area, speed, maneuverability, and gliding ability. FPV aircraft are frequently used for aerial photography and videography, and many videos of FPV flights can be found on popular video sites such as YouTube
YouTube
YouTube is a video-sharing website, created by three former PayPal employees in February 2005, on which users can upload, view and share videos....

 and Vimeo
Vimeo
Vimeo is a video-sharing website on which users can upload, share, and view videos. It was founded by Zach Klein and Jake Lodwick in November 2004...

.

Types of kits and construction

There are various ways to construct and assemble an RC aeroplane. Various kits are available, requiring different amounts of assembly, different costs and varying levels of skill and experience.

Some kits can be mostly foam or plastic, or may be all balsa
Balsa
Ochroma pyramidale, commonly known as the balsa tree , is a species of flowering plant in the mallow family, Malvaceae. It is a large, fast-growing tree that can grow up to tall. It is the source of balsa wood, a very lightweight material with many uses...

 wood. Construction consists of using former
Former
thumb|right|150px|Interior of an F-16B with the engine removed showing frames or formers.A former is a structural member of an aircraft fuselage, of which a typical fuselage has a series from the nose to the empennage, typically perpendicular to the longitudinal axis of the aircraft...

s and longeron
Longeron
In aircraft construction, a longeron or stringer or stiffener is a thin strip of wood, metal or carbon fiber, to which the skin of the aircraft is fastened. In the fuselage, longerons are attached to formers and run the longitudinal direction of the aircraft...

s for the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...

, and spar
Spar
In sailing, a spar is a pole of wood, metal or lightweight materials such as carbon fiber used on a sailing vessel. Spars of all types In sailing, a spar is a pole of wood, metal or lightweight materials such as carbon fiber used on a sailing vessel. Spars of all types In sailing, a spar is a...

s and rib
Rib
In vertebrate anatomy, ribs are the long curved bones which form the rib cage. In most vertebrates, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax...

s for the wings and tail surfaces. More robust designs often use solid sheets of wood to form these structures instead, or might employ a composite wing consisting of an expanded polystyrene core covered in a protective veneer of wood, often obechi. Such designs tend to be heavier than an equivalent sized model built using the traditional method, and would be much more likely to be found in a power model than a glider. The lightest models are suitable for indoor flight, in a windless environment. Some of these are made by bringing frames of balsa wood and carbon fiber up through water to pick up thin plastic films, similar to rainbow colored oil films. The advent of "foamies," or craft injection-molded from lightweight foam and sometimes reinforced with carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...

, have made indoor flight more readily accessible to hobbyists. "Crash proof" EPP (Expanded Polypropylene) foam planes are actually even bendable and usually sustain very little or no damage in the event of an accident, even after a nose dive. Some companies have developed similar material with different names, such as AeroCell or Elapor.

The late 1980s saw a range of models from the United States company US AirCore cleverly using twinwall polypropylene material. This double skinned 'Correx' or 'Coroplast' was commonly used in advertising and industry, being readily available in flat sheet form, easily printed and die cut. Models were pre-decorated and available in ARTF form requiring relatively straightforward, interlocking assembly secured with contact adhesive. The material thickness (usually 3~6mm) and corresponding density meant that models were quite weighty (upwards of 5 lb
Pound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...

 or 2 kg) and consequently had above average flying speeds. The range were powered using a clever (interchangeable) cartridge motor mount designed for the better, more powerful 0.40 cu in (6.6 cm³) glow engines. Aircore faded from the scene around the Millennium.

Coincidently this is when the material was used experimentally by Mugi-the small tough delta glider was invented. This rapidly developed into a high performance design-the Mugi Evo. Popular worldwide as the plans were immediately launched freely on the Internet. Any grade or thickness of the material can be used by appropriate scaling. However the optimum material is twinwalled polypropylene sheet in 2mm thickness and at 350gsm (density)

Amateur hobbyists have more recently developed a range of new model designs utilizing the corrugated plastic
Corrugated plastic
Corrugated plastic or corriboard - also known under the tradenames of Coroplast, IntePro, Correx, Twinplast, Corriflute or Corflute - refers to a wide range of extruded twinwall plastic-sheet products produced from high-impact polypropylene resin with a similar make-up to corrugated fiberboard. It...

 or "Coroplast" material. These models are collectively called "SPADs" which stands for Simple Plastic Airplane Design
Simple Plastic Airplane Design
Simple Plastic Airplane Design is term used to describe a type of radio controlled airplane.The R.C. aircraft is usually, though not always, built with the body consisting of a lightweight plastic material such as PVC gutter downspout or an aluminium rail...

. Fans of the SPAD concept tout increased durability, ease of building, and lower priced materials as opposed to balsa models, sometimes (though not always) at the expense of greater weight and crude appearance.

Flying models have to be designed according to the same principles
Aerodynamics
Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

 as full-sized aircraft, and therefore their construction can be very different from most static models. RC planes often borrow construction techniques from vintage full-sized aircraft (although they rarely use metal structures).

Ready to fly

Ready to fly (or RTF) planes come as pre-assembled kits that usually only require wing attachment or other basic assembly. Typically, everything that is needed is already in the kit. RTF planes can be up in the air in just a few minutes and have all but eliminated assembly time (at the expense of the model's configuration options.) Among traditional hobbyist builders, RTF models are a point of controversy, as many consider model assembly, fabrication and even design as integral to the hobby.

Almost ready to fly

Almost ready to fly (or ARF or ARTF) kits are similar to RTF kits; however usually require more assembly and sometimes basic construction. The average ARF aircraft can be built with less than 4 hours of labor, versus 20–50+ hours (depending on detail and desired results) for a traditional kit aircraft. The fuselage and appendages are normally already constructed. The kit will usually require separate purchase and installation of servos, choice of motor (gas, glow fuel, or electric), speed controller (electric) and occasionally control rod
Control rod
A control rod is a rod made of chemical elements capable of absorbing many neutrons without fissioning themselves. They are used in nuclear reactors to control the rate of fission of uranium and plutonium...

s. This is an advantage over RTF kits, as most model aircraft enthusiasts already own their equipment of choice, and only desire an airframe.

Balsa kit

Balsa kit
Kit
-Animals:* kit, a young ferret* a short form of kitten, a young cat* Kit fox, a relatively common North American fox* Kit, a group of domestic pigeons trained to perform together in competitions-Companies and organisations:...

s come in many sizes and skill levels. The balsa wood may either be cut with a die-cut or laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

. Laser cut kits have a much more precise construction and much tighter tolerance
Tolerance (engineering)
Engineering tolerance is the permissible limit or limits of variation in# a physical dimension,# a measured value or physical property of a material, manufactured object, system, or service,# other measured values ....

s, but tend to cost more than die-cut kits.

The kit usually contains most of the raw material needed for an unassembled plane, a set of (sometimes elaborate) assembly instructions, and a few spare parts to allow for builder error. Assembling a model from plans or a kit can be very labor-intensive. In order to complete the construction of a model, the builder typically spends many hours assembling the frame, covering it, and polishing/refining the control surfaces for correct alignment. The kit does not include necessary tools, and these have to be purchased separately. A single overlooked error during assembly could compromise the model's airworthiness, leading to a crash that destroys the model.

Smaller balsa kits will often come complete with the necessary parts for the primary purpose of non-flying modeling or rubber band flight. These kits will usually also come with conversion instructions to fly as glow (gas powered) or electric and can be flown free-flight
Free flight (model aircraft)
The segment of model aviation known as free flight is the original form of the aeromodeling hobby, extending back centuries.- Description :...

 or radio-controlled. Converting a kit requires additional and substitution parts to get it to fly properly such as the addition of servos, hinges, speed controls, control rods and better landing gear mechanisms and wheels.

Many kits will come with a tissue paper covering that then gets covered with multiple layers of plane dope
Aircraft dope
thumb|right|[[United Kingdom military aircraft serials|2699]] a [[World War I]] [[Royal Aircraft Factory B.E.2]] finished in a clear dopeAircraft dope is a plasticised lacquer that is applied to fabric-covered aircraft...

 which coats and strengthens the fuselage and wings in a plastic-like covering. It has become more common to cover planes with heat-shrinking plastic films backed with heat-sensitive adhesive. These films are generally known as 'iron-on covering' since a hand-held iron allows the film to be attached to the frame; a higher temperature then causes the film to tighten. This plastic covering is more durable and makes for a quick repair. Other varieties of heat shrinkable coverings are also available, that have fibrous reinforcements within the plastic film, or are actual woven heat shrinkable fabrics.

It is common to leave landing gear off smaller planes (roughly 36" or smaller) in order to save on weight, drag and construction costs. The planes can then be launched by hand-launching, as with smaller free-flight models, and can then land in soft grass.

From plans or scratch

Planes can be built from published plan
Plan
A plan is typically any diagram or list of steps with timing and resources, used to achieve an objective. See also strategy. It is commonly understood as a temporal set of intended actions, through which one expects to achieve a goal...

s, often supplied as full-sized drawings with included instructions. Parts normally need to be cut out from sheet wood using supplied templates. Once all of the parts have been made, the project builds up just like another kit. A model plane built from scratch ends up with more value because you created the project from the plans. There is more choice of plans and materials than with kits, and the latest and more specialized designs are usually not available in kit form. The plans can be scaled to any desired size with a computer or copy machine, usually with little or no loss in aerodynamic efficiency.

Hobbyists that have gained some experience in constructing and flying from kits and plans will often venture into building custom planes from scratch. This involves finding drawings of full-sized aircraft and scaling these down, or even designing the entire airframe from scratch. It requires a solid knowledge of aerodynamics and a plane's control surfaces. Plans can be drawn up on paper or done with CAD software. Many CAD packages exist for the specific purpose of designing planes and perfecting airfoils.

Construction

Several materials are commonly used for construction of the airframe of model radio controlled aircraft.

The earliest model radio controlled aircraft were constructed of wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 covered with paper. Later, plastic film came to be widely used as a covering material. Wood has relatively low cost, high specific Young's modulus
Young's modulus
Young's modulus is a measure of the stiffness of an elastic material and is a quantity used to characterize materials. It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke's Law holds. In solid mechanics, the slope of the stress-strain...

 (stiffness per unit weight), good workability and strength, and can be assembled with adhesives of various types. Light-weight strong varieties such as balsa wood are preferred; basswood, pine and spruce
Spruce
A spruce is a tree of the genus Picea , a genus of about 35 species of coniferous evergreen trees in the Family Pinaceae, found in the northern temperate and boreal regions of the earth. Spruces are large trees, from tall when mature, and can be distinguished by their whorled branches and conical...

 are also used.

Carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...

, in rod or strip form, supplements wood in more recent models to reinforce the structure, and replaces it entirely in some cases (such as high performance turbine engine powered models and helicopters).

Expanded polystyrene
Polystyrene
Polystyrene ) also known as Thermocole, abbreviated following ISO Standard PS, is an aromatic polymer made from the monomer styrene, a liquid hydrocarbon that is manufactured from petroleum by the chemical industry...

 (Styrofoam
Styrofoam
Styrofoam is a trademark of The Dow Chemical Company for closed-cell currently made for thermal insulation and craft applications. In 1941, researchers in Dow's Chemical Physics Lab found a way to make foamed polystyrene...

) came to be used more recently for the construction of the entire airframe. Depron (the type of foam used for meat trays) blends rigidity with flexibility, allowing aircraft to absorb the stress of flying. Expanded polypropylene (EPP) is an extremely resilient variety of foam, often used in basic trainers, which take considerable abuse from beginners.

High wing

The easiest planes to fly are typically ones that have a high wing, or a wing that is on top or above the plane's fuselage. Wing dihedrals (bend or change of angle in wing relative to fuselage) or polyhedrals are also common. Most trainers and park flyers have this configuration.

These planes hold most of their weight under the canopy of the wing structure and tend to react more like a glider. For this reason, they are very stable and easy to fly. If a high wing plane is out of control, stability can often be regained by returning the controls to a neutral position, allowing the plane to naturally fall back into a gliding position.

High wings are typical of many vintage private planes, such as the Piper Cub and the Cessna 170
Cessna 170
|-See also:-External links:* *...

.

Low wing

Low wing planes offer a higher level of flying difficulty because the weight of the plane sits on top of the wing structure, making the balance a bit top heavy. Most wing configurations provide a slight dihedral to provide a bit more balance during flight.

The weight distribution and wing position of a low wing plane provides a good balance of stability and maneuverability. The plane's moment of inertia about the rotation axis is lower because it is closer to the wing, therefore rolls require much less torque and are more rapid than a high wing plane.

Low wings are typical of 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...

 war planes and many newer passenger planes and commercial jets.

Mid-wing

Mid-wing planes are usually considered the most difficult to fly. The wings are usually located right in the vertical middle of the fuselage, near the bulk mass of the aircraft. Very little leverage is needed to turn and rotate the plane's weight.

Mid-wings are often straight without any dihedral providing an almost symmetrical aerodynamic structure. This allows the plane to be relatively balanced whether right-side-up, upside-down, or any other position. This is great for military jets, sport planes and aerobatic planes, but less advantageous for the learning pilot. Because of this symmetry, the plane does not really have any natural or stable flying position, like the high wing planes, and will not automatically return to a stable gliding position.

Number of channels

The number of channels
Channel (communications)
In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...

 a plane requires is normally determined by the number of mechanical servos
Servomechanism
thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...

 that have been installed (with a few exceptions such as the aileron servos, where two servos can operate via a single Y harness (with one of the two servos rotating in the opposite direction)). On smaller models, usually one servo per control surface (or set of surfaces in the case of ailerons or a split elevator surface) is sufficient.
  • Aileron
    Aileron
    Ailerons are hinged flight control surfaces attached to the trailing edge of the wing of a fixed-wing aircraft. The ailerons are used to control the aircraft in roll, which results in a change in heading due to the tilting of the lift vector...

    s - controls roll.
  • Elevator
    Elevator (aircraft)
    Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's orientation by changing the pitch of the aircraft, and so also the angle of attack of the wing. In simplified terms, they make the aircraft nose-up or nose-down...

     - controls pitch (up and down).
  • Throttle
    Throttle
    A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases , but usually decreased. The term throttle has come to refer, informally and incorrectly, to any mechanism by which...

     or, if electric, motor speed.
  • Rudder (or vertical stabilizer)- controls yaw (left and right).
  • Gear/retracts - controls retractable landing gear
    Landing Gear
    Landing Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...

     (usually in conjunction with gear doors).
  • Flaps
    Flap (aircraft)
    Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...

     - Increase lift, but also increase drag. Using flaps, an aircraft can fly slower before stalling. Flaps are often used to steepen the landing approach angle and let the plane land at a slower touchdown speed (as well as letting the aircraft lift off at a slower takeoff speed). In both cases, flaps enable using a shorter runway than would otherwise be required.
  • Auxiliary control - Additional channels can control additional servos for propeller pitch (such as on 3D planes), or control surfaces such as spoilerons, flaperon
    Flaperon
    A flaperon is a type of aircraft control surface that combines aspects of both flaps and ailerons. In addition to controlling the roll or bank of an aircraft as do conventional ailerons, both flaperons can be lowered together to function similarly to a dedicated set of flaps...

    s, or elevon
    Elevon
    Elevons are aircraft control surfaces that combine the functions of the elevator and the aileron , hence the name. They are frequently used on tailless aircraft such as flying wings. An elevon that is not part of the main wing, but instead is a separate tail surface, is a stabilator...

    s.
  • Misc - bomb bay doors, lights, remote camera shutter can be assigned to extra channels. Additionally, if there is a flight assist or autopilot module on the craft (more common on the multi-rotor copters), features such as gyro-based stabilization, GPS location hold, height hold, return home, etc., can be controlled.


Three channels (controlling rudder, elevator and throttle) are common on trainer aircraft. Four channel aircraft add aileron control.

For complex models and larger scale planes, multiple servos may be used on control surfaces. In such cases, more channels may be required to perform various functions such as deploying retractable landing gear, opening cargo doors, dropping bombs, operating remote cameras, lights, etc.

The right and left ailerons move in opposite directions. However, aileron control will often use two channels to enable mixing of other functions on the transmitter. For example, when they both move downward they can be used as flaps (flaperons), or when they both move upward, as spoilers
Spoiler (aeronautics)
In aeronautics, a spoiler is a device intended to reduce lift in an aircraft. Spoilers are plates on the top surface of a wing which can be extended upward into the airflow and spoil it. By doing so, the spoiler creates a carefully controlled stall over the portion of the wing behind it, greatly...

 (spoileron
Spoileron
In aeronautics spoilerons are flight control surfaces, specifically spoilers that can be used asymmetrically to achieve the effect of ailerons, i.e. to roll an aircraft by reducing the lift of one wing but unlike ailerons not increasing the lift of the other wing...

s). Delta wing
Delta wing
The delta wing is a wing planform in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta .-Delta-shaped stabilizers:...

ed aircraft designs commonly lack a separate elevator, its function being mixed with the ailerons and the combined control surfaces being known as elevons. V-tail mixing, needed for such full-scale aircraft designs as the Beechcraft Bonanza
Beechcraft Bonanza
The Beechcraft Bonanza is an American general aviation aircraft introduced in 1947 by The Beech Aircraft Corporation of Wichita, Kansas. , it is still being produced by Hawker Beechcraft, and has been in continuous production longer than any other airplane in history...

, when modeled as RC scale miniatures, is also done in a similar manner as elevons and flaperons.

Tiny ready to fly RC indoor or indoor/outdoor toy aircraft often have two speed controllers and no servos, as very small and inexpensive servos are not yet available. There can be one motor for propulsion and one for steering or twin motors with the sum controlling the speed and the difference controlling the turn (yaw).

Some .049 glow models use two controls: elevator and rudder with no throttle control. The plane is flown until it runs out of fuel then landed like a glider.

Turning

Turning is generally accomplished by rolling the plane left or right and applying the correct amount of up-elevator ("back pressure").

A three channel RC plane will typically have an elevator and a throttle control, and either an aileron or rudder control but not both.
If the plane has ailerons, rolling the wings left or right is accomplished directly by them. If the plane has a rudder instead, it will be designed with a greater amount of Dihedral Effect, which is the tendency for the airplane to roll in response to sideslip angle created by the rudder deflection. Dihedral Effect in model airplane design is usually increased by increasing the Dihedral Angle of the wing (V-bend in the wing). The rudder will yaw
Yaw
The word yaw can refer to:* Yaw angle, one of the Tait-Bryan angles, describing the heading of a vehicle or machine, and some other related elements:**Yaw system, component responsible for the orientation of a wind turbine towards the wind....

 the plane so that it has a left or right sideslip, dihedral effect will then cause the plane to roll in the same direction. Many trainers, electric park fliers, and gliders use this technique.

A more complex four channel model can have both rudder and ailerons and is usually turned like a full-sized aircraft. That is, the ailerons are used primarily to directly roll the wings, and the rudder is used to "coordinate" (to keep the sideslip angle near-zero during the rolling motion). Sideslip otherwise builds up during an aileron-driven roll because of adverse yaw
Adverse yaw
Adverse yaw is a yaw moment on an aircraft which results from an aileron deflection and a roll rate, such as when entering or exiting a turn. It is called "adverse" because it acts opposite to the yaw moment needed to execute the desired turn. Adverse yaw has three mechanisms, listed below in...

. Often, the transmitter is programmed to automatically apply rudder in proportion to aileron deflection to coordinate the roll.

When an airplane is in a small to moderate bank (roll angle) a small amount of 'back pressure' is required to maintain height. This is required because the lift vector, which would be pointing vertically upwards in level flight, is now angled inwards so some of the lift is turning the aircraft. A higher overall amount of lift is required so that the vertical component remains sufficient for a level turn.

Many radio controlled aircraft, especially the toy class models, are designed to be flown with no movable control surfaces at all. Some model planes are designed this way because it is often cheaper and lighter to control the speed of a motor than it is to provide a moving control surface. Instead, "rudder" control (control over sideslip angle) is provided by differing thrust on two motors, one on each wing. Total power is controlled by increasing or decreasing the power on each motor equally. Usually, the planes only have only these two control channels (total throttle and differential throttle) with no elevator control. Turning a model with differential thrust is equivalent to and just as effective as turning a model with rudder. Lack of elevator control is sometimes problematic if the phugoid
Phugoid
A phugoid or fugoid is an aircraft motion where the vehicle pitches up and climbs, and then pitches down and descends, accompanied by speeding up and slowing down as it goes "uphill" and "downhill." This is one of the basic flight dynamics modes of an aircraft , and a classic example of a positive...

 oscillation isn't well-damped leading to unmanageable "porpoising". See "Toy class RC" section.

V-tail systems

A V-Tail
V-tail
In aircraft, a V-tail is an unconventional arrangement of the tail control surfaces that replaces the traditional fin and horizontal surfaces with two surfaces set in a V-shaped configuration when viewed from the front or rear of the aircraft...

 is a way of combining the control surfaces of the standard "+" configuration of rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...

 and elevator
Elevator (aircraft)
Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's orientation by changing the pitch of the aircraft, and so also the angle of attack of the wing. In simplified terms, they make the aircraft nose-up or nose-down...

 into a V shape. These ruddervators are controlled with two channels and mechanical or electronic mixing. An important part of the V-Tail configuration is the exact angle of the two surfaces relative to each other and the wing, otherwise the ratio of elevator and rudder outputs will be incorrect.

The mixing works as follows: When receiving rudder input, the two servos work together, moving both control surfaces to the left or right, inducing yaw. On elevator input, the servos work opposite, one surface moves to the "left" and the other to the "right" which gives the effect of both moving up and down, causing pitch changes in the aircraft.

V-Tails are very popular in Europe, especially for gliders. In the US, the T-Tail
T-tail
thumb|right|Grob motor gliderA T-tail is an aircraft tail stabilizer configuration in which the horizontal surfaces are mounted to the top of the vertical stabilizer. Traditionally, the horizontal control surfaces are mounted to the fuselage at the base of the vertical stabilizer...

 is more common. V-Tails have the advantage of being lighter and creating less drag. They also are less likely to break at landing or take-off due to the tail striking something on the ground like an ant mound or a rock.

Powerplants

Most planes need a powerplant
PowerPlant
PowerPlant is an object-oriented GUI toolkit, application framework and set of class libraries for Mac OS, created by Metrowerks. The framework was fairly popular at the height of the Classic Mac OS era, and was primarily used with CodeWarrior...

 to drive them, the exception being gliders. The most popular types for radio-controlled aircraft are internal combustion engines, electric motors, jet, and rocket engines. Three types of internal combustion engines are available being small 2 and 4 stoke engines. Glowplug engines which use nitro-methanol as fuel, compressive ignition ('diesel') burn paraffin with ether as an ignition agent. Larger engines can be glowplug but increasingly common gasoline is the fuel of choice.

In recent years electric powered models have increased in popularity due to the reducing cost and weight of components and improvements in technology, especially Lithium-ion polymer batteries and the choice of brushed motors and brushless motors. Electric systems are quieter and as they do not require fuel/exhaust, are cleaner. The advantage of electric power is the ease of starting the motor as compared to the starting of engines; Electric motors that are comparable to engines are cheaper. On the flip side, the modeller needs to take care of the Lithium Polymer (Lipo) batteries as these batteries need special chargers to charge them. Further, Lipo batteries are cost prohibitive and the beginner needs to know the correct method to charge them. All Lipo batteries in one pack have to be charged simultanously with the same charge or else there is a risk of explosion.

Frequency

Frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...

 determines the line of communication between a receiver and transmitter. The transmitter and receiver must both be on the same frequency so the plane can be controlled.

Reserved frequencies

Many countries reserve specific frequency bands (ranges) for radio control use. Due to the longer range and potentially worse consequences of radio interference
Electromagnetic interference
Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...

, model aircraft have exclusive use of their own frequency allocation
Frequency allocation
Use of radio frequency bands of the electromagnetic spectrum is regulated by governments in most countries, in a Spectrum management process known as frequency allocation or spectrum allocation. Radio propagation does not stop at national boundaries...

 in some countries.

USA and Canada reserved frequency bands
  • 72 MHz: aircraft only (France also uses US/Canada channels 21 through 35).
  • 75 MHz: surface vehicles.
  • 50 MHz: on the 6-meter band
    6-meter band
    The 6-meter band is a portion of the VHF radio spectrum allocated to amateur radio use. Although located in the lower portion of the VHF band, it nonetheless occasionally displays propagation mechanisms characteristic of the HF bands. This normally occurs close to sunspot maximum, when solar...

     for all vehicles, with the operator holding a valid amateur radio
    Amateur radio
    Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

     (FCC in the USA) license.
  • 27 MHz: general use, toys.
  • 2.400-2.485 GHz: Spread Spectrum band for general use (amateur radio license holders have 2.39-2.45 GHz licensed for their general use in the USA) and using both frequency-hopping spread spectrum
    Frequency-hopping spread spectrum
    Frequency-hopping spread spectrum is a method of transmitting radio signals by rapidly switching a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver...

     and direct-sequence spread spectrum
    Direct-sequence spread spectrum
    In telecommunications, direct-sequence spread spectrum is a modulation technique. As with other spread spectrum technologies, the transmitted signal takes up more bandwidth than the information signal that is being modulated. The name 'spread spectrum' comes from the fact that the carrier signals...

     RF technology to maximize the number of available frequencies on this band, especially at organized events in North America.

US frequency chart available at http://www.modelaircraft.org/events/frequencies.aspx,
Canadian frequency chart available at http://www.maac.ca/freq_chart.php

European reserved frequency bands
  • 35 MHz: aircraft only.
  • 40 MHz: surface vehicles or aircraft.
  • 27 MHz: general use, toys, citizens band radio.
  • 2.4 GHz spread spectrum: surface vehicles.


Within the 35 MHz range, there are designated A and B bands. Some European countries allow use only in the A band, whereas others allow use in both bands.

Singapore reserved frequency bands
  • 29 MHz: aircraft only


Australian reserved frequency bands
  • 36 MHz: aircraft and water-craft (odd channels for aircraft only)
  • 29 MHz: general use
  • 27 MHz: light electric aircraft, general use
  • 2.400-2.485 GHz: Spread Spectrum band for general use (ACMA references available at http://www.acma.gov.au/)


New Zealand reserved frequency bands
  • 35 MHz: aircraft only
  • 40 MHz: aircraft only
  • 27 MHz: general use
  • 29 MHz: general use
  • 36 MHz: general use
  • 72 MHz: general use (US 72 MHz "even-numbered" channels 12 through 56, at 40 kHz spacing)
  • 2.400-2.4835 GHz: general use

The frequencies are permitted under legislation, provided equipment meets the appropriate standards, bears the New Zealand supplier's Supplier Code Number and has the correct compliance documentation (Radio Spectrum Management information available on the RSM website)

Detailed information, including cautions for transmitting on some of the 'general use' frequencies, can be found on the NZMAA website.

Amateur radio license reserved frequency bands
  • 50 MHz in the USA and Canada
  • 433–434 MHz in Germany (some of these German "ham RC" UHF band channels are also usable by "hams" in Switzerland)

Channels

Traditionally most RC aircraft in the USA utilized a 72 MHz frequency band for communication. The transmitter radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

 broadcasts using AM
Amplitude modulation
Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...

 or FM
Frequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

 using PPM or PCM. Each aircraft needs a way to determine which transmitter to receive communications from, so a specific channel
Channel (communications)
In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...

 within the frequency band is used for each aircraft (except for 2.4 GHz systems which use spread spectrum
Spread spectrum
Spread-spectrum techniques are methods by which a signal generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth...

 modulation, described below).

Most systems use crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

s to set the operating channel in the receiver and transmitter. It is important that each aircraft uses a different channel, otherwise interference could result. For example, if a person is flying an aircraft on channel 35, and someone else turns their radio on the same channel, the aircraft's control will be compromised and the result is almost always a crash. For this reason, when flying at RC airfields, there is normally a board where hobbyists can post their channel flag, so everyone knows what channel they are using, avoiding such incidents.

A modern computer radio transmitter and receiver can be equipped with synthesizer technology, using a phase-locked loop
Phase-locked loop
A phase-locked loop or phase lock loop is a control system that generates an output signal whose phase is related to the phase of an input "reference" signal. It is an electronic circuit consisting of a variable frequency oscillator and a phase detector...

 (PLL), with the advantage of giving the pilot the opportunity to select any of the available channels with no need of changing a crystal. This is very popular in flying clubs where a lot of pilots have to share a limited number of channels. Latest receivers now available use synthesiser technology and are 'locked' to the transmitter being used. Double conversion radio reception is normal and can offer the advantage of a built-in 'failsafe' mode too. Using sythesised receivers saves on crystal costs and enables full use of the bandwidth available, for example the 35MHz band.

Newer Transmitters use spread spectrum
Spread spectrum
Spread-spectrum techniques are methods by which a signal generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth...

 technology in the 2.4 GHz frequency for communication. Spread spectrum technology allows many pilots to transmit in the same band (2.4 GHz) in close proximity to each other with little fear of conflicts. Receivers in this band are virtually immune to most sources of electrical interference. Amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

 licensees in the United States also have general use of an overlapping band in this same area, which exists from 2.39 to 2.45 GHz.

Military usage

Radio-controlled aircraft are also used for military purposes, with their primary task being intelligence-gathering reconnaissance. These are usually vehicles not designed to contain a human pilot (see unmanned aerial vehicle
Unmanned aerial vehicle
An unmanned aerial vehicle , also known as a unmanned aircraft system , remotely piloted aircraft or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously, that is, as a self-directing entity...

). Remotely controlled drone aircraft were used to train gun crews.

See also

  • 3D Aerobatics
    3D Aerobatics
    3D Aerobatics or 3D flying is a form of flying using flying aircraft to perform specific aerial maneuvers. They are usually performed when the aircraft had been intentionally placed in a stalled position.- Introduction :...

  • British Model Flying Association
    British Model Flying Association
    The British Model Flying Association is the body elected by the Royal Aero Club to be responsible for all aspects of flying model aircraft in the UK.-History:...

  • Bruce Simpson
    Bruce Simpson
    For the Canadian pole vaulter with the same name see Bruce Simpson Bruce Simpson is an internet celebrity and activist from New Zealand best known for his long running blog and his 2003 attempt to build a missile with parts ordered from internet retailers.-Aardvark Daily:Simpson's personal website...

     who used RC flight control systems in the construction of a homemade cruise missile
  • Discus Launch Glider
  • Hotliner
    Hotliner
    In radio-controlled aircraft, Hotliner is a term used to describe a fast sailplane with an electric motor. The range of what is often described as a hotliner varies from a sailplane with ailerons to 7000 watt competition F5b planes...

  • International Miniature Aerobatic Club
    International Miniature Aerobatic Club
    International Miniature Aerobatic Club is a non-profit organization devoted to flying scale aerobatic model aircraft. IMAC is the main governing body responsible for hosting precision aerobatic contests with hundreds of pilots across the United States and Eastern Canada...

  • Model Aeronautics Association of Canada
    Model Aeronautics Association of Canada
    The Model Aeronautics Association of Canada is the official organization for all forms of the aeromodeling hobby, for model aircraft hobbyists living in Canada. Based in Burlington, Ontario, it was founded in 1949, and presently has over 13,000 members. MAAC is responsible for instituting official...

  • Radio-controlled model
    Radio-controlled model
    A radio-controlled model is a model that is steerable with the use of radio control. All types of vehicles imaginable have had RC systems installed in them, including cars, boats, planes, and even helicopters and scale railway locomotives....

  • RC Aircraft Kit Manufacturers
  • RC flight simulator
    RC flight simulator
    An RC flight simulator is a computer program that allows pilots of radio-controlled aircraft to practice on a computer, without the risk and expense of a damaging a real model. Besides the obvious use of training beginners, they are also used for practising new aerobatics, evaluating a model before...


External links

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