A radio-controlled aircraft (often called RC aircraft or RC plane) is a model aircraft that is controlled remotely, typically with a hand-held transmitter and a receiver within the craft. The receiver controls the corresponding servos that move the control surfaces based on the position of joysticks on the transmitter, which in turn move the plane.
Flying RC aircraft as a hobby has been growing worldwide with the advent of more efficient motors (both electric and miniature internal combustion or jet engines), lighter and more powerful batteries 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 modeling and testing, and even using them as drones or spy planes.
There are many types of radio-controlled aircraft. For beginning hobbyists, there are park flyers and trainers. For more advanced pilots there are glow plug engine, electric powered and sailplane aircraft. For expert flyers, jets, pylon racers, helicopters, autogyros, 3D aircraft, and other high end competition aircraft provide adequate challenge. You can also build scale models of manned aircraft. Some models are made to look and operate like a bird instead. Other sport aircraft are designated for scale-like flying referred to as "scale". Scale is a very demanding but rewarding aspect of the hobby.
[edit] Sailplanes and gliders
F3A Pattern Ship - ZNline Alliance by CPLR
Shinden by Bryan Hebert
Main article: radio-controlled glider
Gliders 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 thermals or wind hitting a slope. Dynamic soaring is another popular way of providing propulsion to gliders and is commonly employed today.
[edit] Jets
Jets tend to be very expensive and commonly use a micro turbine or ducted fan to power them. Airframes are constructed from fiber glass and carbon 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. The micro turbines start with kerosene, then burn for a few seconds before introducing the jet fuel by solenoid. These aircraft can often reach speeds in excess of 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 (Aeronautical Modelers Association) sites, in where certified turbine pilots may fly. 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 $5000-$20,000. 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 (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 Ion Polymer pack) at 8-12 volts that control the FADEC. There is also a LIPO for the onboard servos that control ailerons, rudder, flaps and landing gear. The Federal Government has recently prohibited such use of RC Jets in urban areas (2006).
[edit] Pylon racers
Racers are small propeller aircraft that race around a 2, 3, or 4 pylon track. They tend to be hard to see and can often go over 240 km/h (150 mph), 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 3,200 square centimetres (500 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 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 km/h (180 mph). 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, with 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 km/h (200 mph) on the course. Because of their limited wing area however, Q50 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.
