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.
Description
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.[1]
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).
Applications
Wing warping was a common feature of early aircraft, including:
The Wright Flyer (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 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 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 derived from the previous G and H
The Caudron G.4 (1915), a French biplane with twin engines.
The Fokker Eindecker (1915), the first German fighter aircraft.
The Fokker D.III (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.[2]
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 a General Dynamics F-111 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. The wings will one day be able to form civilian airplanes that fly in any conditions. Currently, NASA is focusing on unmanned drones. [3]
Inman is another company working on morphing wings. Inman works with bird biologists in the hope of fully mimicking the animals flight patterns. Car companies have invested in Inman for applying wing morphing techniques to cars to make them more fuel efficient.[4]
See also
Aileron
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.
References
"The Wright Brothers | Getting Acquainted with Aeronautics". airandspace.si.edu.
Wheeler, Allen H. Building Aeroplanes for "Those Magnificent Men.". London: G.T. Foulis, 1965.
"The 100-Year-Old Idea That Could Change Flight". www.pbs.org.
"The 100-Year-Old Idea That Could Change Flight". www.pbs.org.
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
Centennial of flight – 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
vte
Aircraft components and systems
Airframe structure
Aft pressure bulkhead Cabane strut Canopy Crack arrestor Cruciform tail Dope Empennage Fabric covering Fairing Flying wires Former Fuselage Hardpoint Interplane strut Jury strut Leading edge Lift strut Longeron Nacelle Rib Ring tail Spar Stabilizer Stressed skin Strut T-tail Tailplane Trailing edge Triple tail Twin tail Vertical stabilizer V-tail Y-tail Wing root Wing tip Wingbox
Flight controls
Aileron Airbrake Artificial feel Autopilot Canard Centre stick Deceleron Dive brake Electro-hydraulic actuator Elevator Elevon Flaperon Flight control modes Fly-by-wire Gust lock Rudder Servo tab Side-stick Spoiler Spoileron Stabilator Stick pusher Stick shaker Trim tab Wing warping Yaw damper Yoke
Aerodynamic and high-lift
devices
Active Aeroelastic Wing Adaptive compliant wing Anti-shock body Blown flap Channel wing Dog-tooth Flap Gouge flap Gurney flap Krueger flap Leading-edge cuff Leading-edge droop flap LEX Slats Slot Stall strips Strake Variable-sweep wing Vortex generator Vortilon Wing fence Winglet
Avionic and flight
instrument systems
ACAS Air data computer Airspeed indicator Altimeter Annunciator panel Attitude indicator Compass Course deviation indicator EFIS EICAS Flight management system Glass cockpit GPS Heading indicator Horizontal situation indicator INS Pitot-static system Radar altimeter TCAS Transponder Turn and slip indicator Variometer Yaw string
Propulsion controls,
devices and fuel systems
Autothrottle Drop tank FADEC Fuel tank Gascolator Inlet cone Intake ramp NACA cowling Self-sealing fuel tank Splitter plate Throttle Thrust lever Thrust reversal Townend ring Wet wing
Landing and arresting gear
Aircraft tire Arrestor hook Autobrake Conventional landing gear Drogue parachute Landing gear Landing gear extender Oleo strut Tricycle landing gear Tundra tire
Escape systems
Ejection seat Escape crew capsule
Other systems
Aircraft lavatory Auxiliary power unit Bleed air system Deicing boot Emergency oxygen system Flight recorder Entertainment system Environmental control system Hydraulic system Ice protection system Landing lights Navigation light Passenger service unit Ram air turbine Weeping wing
Hellenica World - Scientific Library
Retrieved from "http://en.wikipedia.org/"
All text is available under the terms of the GNU Free Documentation License
