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 affect the orientation of 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.
2. TYPES OF RC AIRCRAFT
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, auto gyros, 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 and free flight types of model aircraft, actually reach their maximum realism and behavior when built for radio control flying.
2.1 Radio control scale aircraft modeling
Perhaps the most realistic form of aero modeling, 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 aero modeling. RC Scale model aircraft can be of any type of steerable airship 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 auto gyros or helicopters.
Various scale sizes of RC scale aircraft have been built in the decades since modern digital-proportional, 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 aero modeling hobby.
2.2 Sailplanes and gliders
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.
Jets tend to be very expensive and commonly use a micro turbine or ducted fan to power them. Most airframes are constructed from fiber glass and carbon fiber. Inside the aircraft, wooden spars reinforce the body to make a rigid airframe. 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 200 mph. They require incredibly quick reflexes and very expensive equipment, so are usually reserved for the expert. Smaller turbines put out about 12 lbf (53 N) of thrust, while larger micro turbines 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.
2.4 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. The planes are primarily made of fiberglass with composites used at high load points. Wings are often hollow to save 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 have been designed to put out the maximum amount of power at a specific RPM using a specific fuel. 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, which have much cleaner aerodynamics and less wing area. These planes can fly in excess of 320 km/h (200 mph) on the course. Because of their limited wing area however, Q40 planes must fly a larger arc around the pylons to conserve energy.
Radio-controlled helicopters, although often grouped with RC aircraft, are in a class of their own because of the vast differences in construction, aerodynamics and flight training. 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.
2.6 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. Spectators are often surprised to see that such a model can really fly, and real birds are often surprised by these unexpected visitors in their aerial domain. These factors as well as the added building challenge add to the enjoyment of flying bird models, though some ARF (almost-ready-to-fly) models are available. Flapping-wing models are also known as ornithopters, the technical name for an aircraft whose driving airfoils oscillate instead of rotate.
3. CONTENTS OF THE PROJECT
The project mainly consists of the following for the purpose of surveillance
3.1 RC model
The above figure shows the parts of basic trainer RC model. The description of each parts are given below, Fuselage
Fuselage is the main structural element of the RC Airplane or the body of the RC Airplane. The Wing, Horizontal and Vertical Tail are connected to the fuselage. The Engine is also mounted to the fuselage. The fuselage is made up of bulk-heads. The bulk-heads are structural members which give strength and rigidity to the fuselage, support load and weight of the RC Airplane. The Engine bulk-head is made relatively stronger as compared to other bulk-heads of RC Airplane fuselage because it carriers the load of the engine as well as encounters vibrations during engine operation so it must be strong to resist all the loads.
The nose gear and main landing gear are also connected to the fuselage. The fuselage also houses all the electronic components necessary for RC Airplane flight including ESC (electronic speed controller) in case of electric RC Airplane, Receiver, Servos, Batteries and fuel tank in case of gas powered RC Airplane. External or internal payloads are also carried inside the fuselage. The fuselage can be used to connect an external camera for example or to carry some payload inside the RC Airplane.
Wings are the main lifting body of the RC Airplane providing the lift necessary for RC Airplane flight. The wing provides lift because of its aerodynamic shape which creates a pressure differential causing lift. If a cross-section of the wing is cut, a shape or profile is visible which is called an airfoil. Airfoil shape is the key to the wings ability to provide lift and is airfoil selection and design is an important criterion in the design of RC Airplanes. The front most edge of the wing is known as leading edge and the aft most edge of the wing is known as the trailing edge. There are typically three kinds of airfoils which are used on RC Airplanes namely, symmetrical airfoils, semi-symmetrical airfoils and heavily cambered airfoils. On the wing are mounted the flaps and ailerons.
Ailerons are roll-control control surfaces of the RC Airplanes. Ailerons provide roll by moving in opposite direction to each other. When one aileron moves down the other moves up thus providing more lift on one side as oppose to the other causing the RC Airplane to roll. Ailerons are at the trailing edge of RC Airplane wing and towards the wing tips.
Elevators are the pitch-control control surfaces of the RC Airplanes. Elevators provide pitch control by moving either up or down simultaneously causing the airplane to pitch about the center of gravity of RC Airplane. When elevator is moved up the nose of the airplane rises and is known as pitch up. When the elevator is moved down the nose of the RC Airplane moves down and is known as pitch down.
Rudder is the yaw-control control surface of the RC Airplanes. Rudder provides yaw control by moving to either side be it left or right. The rudder yaws the RC Airplane about the center of gravity cg of RC Airplane causing the RC Airplane nose to move right or to move left. A right rudder maneuver causes the RC Airplane to move to the right. A left rudder maneuver causes the RC Airplane to the left.
Nose gear is a member of the landing gear set on a typical conventional RC Airplane configuration. The nose gear is used to steer the RC Airplane nose to move RC Airplane right or left when on the ground. The servo which connects the nose gear is also connected to the rudder. So, the direction in which the rudder moves the nose gear also follows that direction. During takeoff the nose gear is used to steer the RC Airplane so that RC Airplane is centered to the runway. Without a steerable nose gear it is not possible to maneuver/ move on the ground without manually moving it. With a steerable nose gear the RC Airplane can be moved on the ground.
Main Gear or Landing Gear
The main gear or landing gear are the main landing wheels of the RC
Airplanes which takes the entire RC Airplane. Main gear have to be strong and yet flexible enough to provide safe takeoff and landing to RC Airplane. A rigid inflexible landing gear can damage the RC Airplane structure as the entire weight / reaction force would be carried by the fuselage. So, in order to avoid this landing gears are designed to be strong yet flexible enough so they bend slightly during landing or takeoff to disperse the load and provides safe and smooth landing. Landing gear or Main gears consist of a pair of wheels which are generally larger in diameter as compared to the nose gear wheel. The landing gear wheels are not steerable.
Engine is the main power-plant of RC Airplane. The power-plant of RC Airplanes can be electric motor, internal combustion gas engines and jet engines. The engine is mounted on the RC Airplanes and provides thrust to the RC Airplanes. Thrust is the forward force necessary for flight. The engines run a propeller.