
Wing warping was an early system for lateral (roll) control of a fixed-wing aircraft or kite. The technique, used and patented by the
Wright brothers
The Wright brothers, Orville Wright (August 19, 1871 – January 30, 1948) and Wilbur Wright (April 16, 1867 – May 30, 1912), were American aviation List of aviation pioneers, pioneers generally credited with inventing, building, and flyin ...
, 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.
Description
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."
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.
In practice, since most wing warping designs involved flexing of structural members, they were difficult to control and liable to cause structural failure.
Aileron
An aileron (French for "little wing" or "fin") 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 (or movement aroun ...
s had begun to replace wing warping as the most common means of achieving lateral control as early as 1911, especially in
biplane
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 ...
designs.
Monoplane
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings.
A monoplane has inherently the highest efficiency and lowest drag of any wing con ...
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).
Applications
Wing warping was a common feature of early aircraft, including:
*The
Albatross (1868)
*The
Wright Flyer
The ''Wright Flyer'' (also known as the ''Kitty Hawk'', ''Flyer'' I or the 1903 ''Flyer'') made the first sustained flight by a manned heavier-than-air powered and controlled aircraft on December 17, 1903. Invented and flown by brothers Wrigh ...
(1903)
*The
Santos-Dumont Demoiselle (1907), the first homebuilt.
*The
Antoinette V (1908), a wing-warping variant of the
Antoinette IV
*The
Blériot XI (1909), which made the first flight across a major body of water, namely the
English Channel
The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...
.
*The
Etrich Taube (1910) originally used a cable-warped horizontal stabilizer to give
elevator functionality as well
*The
Nieuport IV (1911) racing and sport monoplane used for the first loop.
*The
Bristol Coanda Monoplanes (1912), whose structural failures (along with those of a
Deperdussin monoplane) led to a ban on monoplanes with the
Royal Flying Corps
The Royal Flying Corps (RFC) was the air arm of the British Army before and during the First World War until it merged with the Royal Naval Air Service on 1 April 1918 to form the Royal Air Force. During the early part of the war, the RFC sup ...
.
*The early versions of the
Royal Aircraft Factory B.E.2 (1912) used wing warping, while the "C" variant and later used ailerons.
*The
Morane-Saulnier L (1913), the first fighter aircraft, and the first to shoot down another aircraft.
*The
Morane-Saulnier N (1914), a World War I French
scout
Scout may refer to:
Youth movement
*Scout (Scouting), a child, usually 10–18 years of age, participating in the worldwide Scouting movement
** Scouts (The Scout Association), section for 10-14 year olds in the United Kingdom
** Scouts BSA, sect ...
derived from the previous
G and
H
*The
Caudron G.4 (1915), a French biplane with twin engines.
*The
Fokker Eindecker
The Fokker ''Eindecker'' fighters were a series of German World War I monoplane single-seat fighter aircraft designed by Netherlands, Dutch engineer Anthony Fokker.Boyne 1988 Developed in April 1915, the first ''Eindecker'' ("Monoplane") was the ...
(1915), the first German fighter aircraft.
*The
Fokker D.III
The Fokker D.III (Fokker designation M.19) was a German single-seat fighter aircraft of World War I. It saw limited frontline service before being withdrawn from combat in December 1916.
Design and development
The M.19 began as an effort to imp ...
(1916), one of the last operational fighters with wing warping.
*The
Christmas Bullet (1919), whose wing warping and unbraced sprung steel spars contributed to its notoriety.
Modern re-assessment
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.
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
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
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.
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.
See also
*
Aileron
An aileron (French for "little wing" or "fin") 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 (or movement aroun ...
*
M. P. W. Boulton, the British inventor (1868) of the aileron
*
Elevon – a combination
elevator/aileron used on
Bleriot's earliest designs and more recently on
flying wing and
delta wing aircraft.
*
Sport kite
References
External links
NASA– interactive diagram of wing warping used on the Wright Flyer
Park Ranger demonstrates wing warping on a reproduction of the 1902 Flyer at the Wright Brothers National Memorial– illustration of Wilbur Wright invention of wing warping using a cardboard box
Aerospaceweb– Origins of Control Surfaces
PBS– What's Wing Warping?
Flight demo of Owl's Head Transportation Museum's Etrich Taube reproduction, demonstrating warping wingtips and stabilizer
{{Aircraft components
Aerodynamics
Aircraft wing design
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