Glider (aircraft)
There are a wide variety of types differing in the construction of their wings, aerodynamic efficiency, location of the pilot, controls and intended purpose.
[2] Early pre-modern accounts of flight are in most cases difficult to verify and it is unclear whether each craft was a glider, kite or parachute and to what degree they were truly controllable.
A 17th-century account reports an attempt at flight by the 9th-century poet Abbas Ibn Firnas near Córdoba, Spain which ended in heavy back injuries.
[5] Hezârfen Ahmed Çelebi is alleged to have flown a glider with eagle-like wings over the Bosphorus strait from the Galata Tower to Üsküdar district in Istanbul around 1630–1632.
[6][7][8] The first heavier-than-air (i.e. non-balloon) man-carrying aircraft that were based on published scientific principles were Sir George Cayley's series of gliders which achieved brief wing-borne hops from around 1849.
Thereafter gliders were built by pioneers such as Jean Marie Le Bris, John J. Montgomery, Otto Lilienthal, Percy Pilcher, Octave Chanute and Augustus Moore Herring to develop aviation.
[9] The Wright Brothers developed a series of three manned gliders after preliminary tests with a kite as they worked towards achieving powered flight.
A glider – the Colditz Cock – was even built secretly by POWs as a potential escape method at Oflag IV-C near the end of the war in 1944.
Charles Richards and Paul Bikle developed the concept producing a wing that was simple to build which was capable of slow flight and as gentle landing.
[13] After tests on Hunter Mountain, New York in September 1965, he went on to promote "slope soaring" as a summer activity for ski resorts (apparently without great success).
Gliders were mainly built of wood and metal but the majority now have composite materials using glass, carbon fibre and aramid fibers.
As technology and materials developed, the aspiration for the perfect balance between lift/drag, climbing ratio and gliding speed, made engineers from various producers create similar designs across the world.
Unlike a sailplane, a hang glider is capable of being carried, foot launched and landed solely by the use of the pilot's legs.
[17] In a hang glider the shape of the wing is determined by a structure, and it is this that distinguishes them from the other main type of foot-launched aircraft, paragliders, technically Class 3.
Due to their commonality of parts, construction and design, they are usually considered by aviation authorities to be hang gliders, even though they may use the engine for the entire flight.
The paraglider's light and simple design allows them to be packed and carried in large backpacks, and make them one of the simplest and economical modes of flight.
These aircraft were towed into the air and most of the way to their target by military transport planes, e.g. C-47 Dakota, or by bombers that had been relegated to secondary activities, e.g. Short Stirling.
By the time of the Korean War, transport aircraft had also become larger and more efficient so that even light tanks could be dropped by parachute, causing gliders to fall out of favor.
Traditional space capsules have little directional control while conventionally winged craft cannot handle the stresses of re-entry, whereas a lifting body combines the benefits of both.
The NASA Paresev Rogallo flexible wing glider was built to investigate alternative methods of recovering spacecraft.
Although this application was abandoned, publicity inspired hobbyists to adapt the flexible wing airfoil for modern hang gliders.
Recent examples of rocket glider include the privately funded SpaceShipOne which is intended for sub-orbital flight and the XCOR EZ-Rocket which is being used to test engines.
Most unpowered rotary-wing aircraft are kites rather than gliders, i.e. they are usually towed behind a car or boat rather than being capable of free flight.
Other methods of launching include towing aloft using a model powered aircraft, catapult-launching using an elastic bungee cord and hand-launching.
