Wing warping was an early system for lateral (roll) control of a fixed-wing aircraft. The technique, used and patented by the Wright brothers, consisted of a system of pulleys and cables to twist the trailing edges of the wings in opposite directions. In many respects, this approach is similar to that used to trim the performance of a paper airplane by curling the paper at the back of its wings. [1]
In 1900, Wilbur Wright wrote, "...my observations of the flight of birds convince me that birds use more positive and energetic methods of regaining equilibrium than that of shifting the center of gravity...they regain their lateral balance...by a torsion of the tips of the wings. If the rear edge of the right wing tip is twisted upward and the left downward the bird becomes an animated windmill and instantly begins to turn, a line from its head to its tail being the axis." After Wilbur demonstrated the method, Orville noted, "From this it was apparent that the wings of a machine of the Chanute double-deck type, with the fore-and-aft trussing removed, could be warped in like manner, so that in flying the wings on the right and left sides could be warped so as to present their surfaces to the air at different angles of incidence and thus secure unequal lifts on the two sides." [2]
Birds visibly use wing warping to achieve control. This was a significant influence on early aircraft designers. The Wright brothers were the first group to use warping wings. Their first plane mimicked the bird's flight patterns and wing form. [3]
In practice, since most wing warping designs involved flexing of structural members, they were difficult to control and liable to cause structural failure. Ailerons had begun to replace wing warping as the most common means of achieving lateral control as early as 1911, especially in biplane designs. Monoplane wings of the period were much more flexible, and proved more amenable to wing warping – but even for monoplane designs, ailerons became the norm after 1915.
Lateral (roll) control in early aircraft was problematic at best. An overly flexible, involuntarily twisting wing can cause involuntary rolling, but even worse, it can convert attempts at correction, either from wing warping or ailerons, into a counteracting "servo tab" effect. Once this was fully understood, wing structures were made progressively more rigid, precluding wing warping altogether – and aircraft became far more controllable in the lateral plane.
Current technology has allowed scientists to revisit the concept of wing warping (also known as morphing wings).
Wing warping was a common feature of early aircraft, including:
Several of the reproduction planes built for the film Those Magnificent Men in Their Flying Machines used the wing warping control systems of the original aircraft – with mixed results. The wing warping of the Avro Triplane proved surprisingly successful, whereas on the reproduction Antoinette, with its very flexible wing, wing warping offered little effective lateral control. Since the original Antoinette-style ailerons would have probably been even less effective, unobtrusive "modern" ailerons were inserted – even with these, lateral control remained very poor. [4]
Wing morphing is a modern-day extension of wing warping in which the aerodynamic shape of the wing is modified under computer control. Research into this field is mainly conducted by NASA such as with the Mission Adaptive Wing (MAW) trialed from 1985 on the General Dynamics–Boeing AFTI/F-111A Aardvark.
Many major companies and scientists are working on developing morphing wings. NASA is working to develop a morphing wing made of cells that will twist to mimic birds. The cells NASA is using to construct the wing are small black modules consisting of carbon fiber. Currently, NASA is focusing on unmanned drones. [5]
The appeal of shape-changing wings lies in the gapless and smooth nature of the resulting geometries. In contrast to conventional wings, relying on discrete, moveable parts (ailerons, flaps, slats...) to achieve variations of their shape – and hence of their aerodynamic properties – morphing wings attain these geometrical variations with continuous deformations of their outer surface. The absence of discrete curvature changes and of gaps has the potential of reducing the shape drag associated to the wing, thus increasing their aerodynamic efficiency. This characteristic makes adaptive wings well-suited to operate at various different operational conditions, as they can optimally adapt their shape and thus minimize the resulting drag.
A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane, which is capable of flight using aerodynamic lift. Fixed-wing aircraft are distinct from rotary-wing aircraft, and ornithopters. The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang gliders, variable-sweep wing aircraft, and airplanes that use wing morphing are all classified as fixed-wing aircraft.
A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a biplane wing structure has a structural advantage over a monoplane, it produces more drag than a monoplane wing. Improved structural techniques, better materials and higher speeds made the biplane configuration obsolete for most purposes by the late 1930s.
The Wright brothers, Orville Wright and Wilbur Wright, were American aviation pioneers generally credited with inventing, building, and flying the world's first successful airplane. They made the first controlled, sustained flight of an engine-powered, heavier-than-air aircraft with the Wright Flyer on December 17, 1903, four miles (6 km) south of Kitty Hawk, North Carolina, at what is now known as Kill Devil Hills. In 1904 the Wright brothers developed the Wright Flyer II, which made longer-duration flights including the first circle, followed in 1905 by the first truly practical fixed-wing aircraft, the Wright Flyer III.
An aileron is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll, which normally results in a change in flight path due to the tilting of the lift vector. Movement around this axis is called 'rolling' or 'banking'.
Aircraft flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude.
In aviation, an aircraft is said to have relaxed stability if it has low or negative stability.
Control reversal is an adverse effect on the controllability of aircraft. The flight controls reverse themselves in a way that is not intuitive, so pilots may not be aware of the situation and therefore provide the wrong inputs; in order to roll to the left, for instance, they have to push the control stick to the right, the opposite of the normal direction.
The Etrich Taube, also known by the names of the various later manufacturers who built versions of the type, such as the Rumpler Taube, was a pre-World War I monoplane aircraft. It was the first military aeroplane to be mass-produced in Germany.
A conventional fixed-wing aircraft flight control system (AFCS) consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered flight controls as they change speed.
The Wright Flyer made the first sustained flight by a manned heavier-than-air powered and controlled aircraft—an airplane—on December 17, 1903. Invented and flown by brothers Orville and Wilbur Wright, it marked the beginning of the pioneer era of aviation.
Early flying machines include all forms of aircraft studied or constructed before the development of the modern aeroplane by 1910. The story of modern flight begins more than a century before the first successful manned aeroplane, and the earliest aircraft thousands of years before.
In aeronautics, spoilerons are spoilers that can be used asymmetrically as flight control surfaces to provide roll control.
The X-53 Active Aeroelastic Wing (AAW) development program is a completed American research project that was undertaken jointly by the Air Force Research Laboratory (AFRL), Boeing Phantom Works and NASA's Dryden Flight Research Center, where the technology was flight tested on a modified McDonnell Douglas F/A-18 Hornet. Active Aeroelastic Wing Technology is a technology that integrates wing aerodynamics, controls, and structure to harness and control wing aeroelastic twist at high speeds and dynamic pressures. By using multiple leading and trailing edge controls like "aerodynamic tabs", subtle amounts of aeroelastic twist can be controlled to provide large amounts of wing control power, while minimizing maneuver air loads at high wing strain conditions or aerodynamic drag at low wing strain conditions. This program was the first full-scale proof of AAW technology.
The Antoinette IV was an early French monoplane.
In aeronautics, a tailless aircraft is an aircraft with no other horizontal aerodynamic surface besides its main wing. It may still have a fuselage, vertical tail fin, and/or vertical rudder.
The wing configuration of a fixed-wing aircraft is its arrangement of lifting and related surfaces.
In aeronautics, a flexible wing is an airfoil or aircraft wing which can deform in flight.
The Wright brothers patent war centers on the patent that the Wright brothers received for their method of airplane flight control. They were two Americans who are widely credited with inventing and building the world's first flyable airplane and making the first controlled, powered, and sustained heavier-than-air human flight on December 17, 1903.
The Avro Burga was built by Avro for R.F. Burga to test his unique system of lateral control. It was a single-engined two-seat monoplane, fitted with differentially operated surfaces above and below the central fuselage.
The pioneer era of aviation was the period of aviation history between the first successful powered flight, generally accepted to have been made by the Wright Brothers on 17 December 1903, and the outbreak of the First World War in August 1914.