Round-the-pole flying
Encyclopedia
Round-the-pole flying is a form of flying model aircraft
, in which the model is attached via a line from its wingtip or fuselage to a central support structure. Control signals can be passed to the model via wires alongside or integral with the attachment line. The operator can control the aircraft using a control console, situated outside the flying circle of the aircraft. Contrast this to control line
flying where the pilot/operator stands at the centre of the flying circle and directly supports the aircraft.
RTP can be used indoors or outdoors, though usually requires calm wind conditions if used outdoors. The power source for the model is usually an electric motor
, since the power can be supplied via the line and heavy batteries
need not be carried. This makes it particularly quiet, clean and suitable for indoor flying. Conventional engines
can be used outdoors.
The pole itself is usually a simple stand heavy enough to withstand the centrifugal force
s on it. The head of the pole needs to provide a freely rotating hub, and usually incorporates a ball bearing
race of some kind. In addition, where signals and power need to pass to the model, some form of slip ring
arrangement is required.
Models for RTP can range from the very simple, usually converted from rubber-band powered models, to sophisticated true scale designs. The use of electric power can permit sophisticated control effects such as retracting undercarriage, operating flaps, etc. However the limited degree of freedom of the tethered model precludes the use of full aerodynamic control. Climb and descent are usually effected using variations in power to the motors.
The control console can be nothing more than a simple rheostat allowing the current supplied to the model to be varied. More sophisticated control consoles can be envisaged.
Typical RTP set-ups allow multiple models to fly simultaneously on the same pole. This allows such activities as formation flying and dogfight
s to take place. A kill in a dogfight is achieved by damaging the opponent's model with the propeller
of the attacking model. Alternatively a paper streamer can be trailed behind each model and a kill is confirmed when the streamer has been successfully destroyed.
Other challenges such as flying under, over and between bars, popping balloons and loop the loop
can also be attempted.
A yearly RTP Contest is held in Lake Tahoe, California. Called the Aaroone Cup, it requires 0.020 engines and is a speed and Concours d'Elegance contest. Record speeds exceed 60 mph on the 10-foot steel line.
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...
, in which the model is attached via a line from its wingtip or fuselage to a central support structure. Control signals can be passed to the model via wires alongside or integral with the attachment line. The operator can control the aircraft using a control console, situated outside the flying circle of the aircraft. Contrast this to 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...
flying where the pilot/operator stands at the centre of the flying circle and directly supports the aircraft.
RTP can be used indoors or outdoors, though usually requires calm wind conditions if used outdoors. The power source for the model is usually an electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
, since the power can be supplied via the line and heavy 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...
need not be carried. This makes it particularly quiet, clean and suitable for indoor flying. Conventional engines
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...
can be used outdoors.
The pole itself is usually a simple stand heavy enough to withstand the centrifugal force
Centrifugal force
Centrifugal force can generally be any force directed outward relative to some origin. More particularly, in classical mechanics, the centrifugal force is an outward force which arises when describing the motion of objects in a rotating reference frame...
s on it. The head of the pole needs to provide a freely rotating hub, and usually incorporates a ball bearing
Ball bearing
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit...
race of some kind. In addition, where signals and power need to pass to the model, some form of slip ring
Slip ring
A slip ring is a method of making an electrical connection through a rotating assembly. Slip rings, also called rotary electrical interfaces, rotating electrical connectors, collectors, swivels, or electrical rotary joints, are commonly found in electric motors, electrical generators for AC...
arrangement is required.
Models for RTP can range from the very simple, usually converted from rubber-band powered models, to sophisticated true scale designs. The use of electric power can permit sophisticated control effects such as retracting undercarriage, operating flaps, etc. However the limited degree of freedom of the tethered model precludes the use of full aerodynamic control. Climb and descent are usually effected using variations in power to the motors.
The control console can be nothing more than a simple rheostat allowing the current supplied to the model to be varied. More sophisticated control consoles can be envisaged.
Typical RTP set-ups allow multiple models to fly simultaneously on the same pole. This allows such activities as formation flying and dogfight
Dogfight
A dogfight, or dog fight, is a form of aerial combat between fighter aircraft; in particular, combat of maneuver at short range, where each side is aware of the other's presence. Dogfighting first appeared during World War I, shortly after the invention of the airplane...
s to take place. A kill in a dogfight is achieved by damaging the opponent's model with the 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...
of the attacking model. Alternatively a paper streamer can be trailed behind each model and a kill is confirmed when the streamer has been successfully destroyed.
Other challenges such as flying under, over and between bars, popping balloons and loop the loop
Aerobatic maneuver
Aerobatic maneuvers are flight paths putting aircraft in unusual attitudes, in air shows, dog fights or competition aerobatics. Aerobatics can be performed by a single aircraft or in formation with several others...
can also be attempted.
A yearly RTP Contest is held in Lake Tahoe, California. Called the Aaroone Cup, it requires 0.020 engines and is a speed and Concours d'Elegance contest. Record speeds exceed 60 mph on the 10-foot steel line.