A point of sail is a sailing craft's direction of travel under sail in relation to the true wind direction over the surface.
102-418: Wingtip devices are intended to improve the efficiency of fixed-wing aircraft by reducing drag . Although there are several types of wing tip devices which function in different manners, their intended effect is always to reduce an aircraft's drag. Wingtip devices can also improve aircraft handling characteristics and enhance safety for following aircraft. Such devices increase the effective aspect ratio of
204-457: A closed-surface Spiroid winglet on a Falcon 50 in 2010. Non-planar wingtips are normally angled upwards in a polyhedral wing configuration, increasing the local dihedral near the wing tip, with polyhedral wing designs themselves having been popular on free-flight model aircraft designs for decades. Non-planar wingtips provide the wake control benefit of winglets, with less parasitic drag penalty, if designed carefully. The non-planar wing tip
306-507: A parachute drop zone . The gliders were treated as disposable, constructed from inexpensive materials such as wood, though a few were re-used. By the time of the Korean War , transport aircraft had become larger and more efficient so that even light tanks could be dropped by parachute, obsoleting gliders. Even after the development of powered aircraft, gliders continued to be used for aviation research . The NASA Paresev Rogallo flexible wing
408-456: A pilot , but some are unmanned and controlled either remotely or autonomously. Kites were used approximately 2,800 years ago in China, where kite building materials were available. Leaf kites may have been flown earlier in what is now Sulawesi , based on their interpretation of cave paintings on nearby Muna Island . By at least 549 AD paper kites were flying, as recorded that year, a paper kite
510-581: A 170 ft (51.7 m) wingspan to fit in ICAO Aerodrome Reference Code D, as its wingspan was decreased by using blended winglets instead of raked wingtips ), and the Boeing 747-8 (February 8, 2010). The Embraer E-jet E2 and C-390 Millennium wings also have raked wingtips. The McDonnell Douglas MD-11 was the first aircraft with split-tip winglets in 1990. For the 737 Next Generation , third-party vendor Aviation Partners has introduced
612-488: A 6% decrease in in-flight noise from the use of winglets. Actual fuel savings and the related carbon output can vary significantly by plane, route and flight conditions. A wingtip fence refers to the winglets including surfaces extending both above and below the wingtip, as described in Whitcomb's early research. Both surfaces are shorter than or equivalent to a winglet possessing similar aerodynamic benefits. The Airbus A310-300
714-659: A Vickers Vimy in 1919 , followed months later by the U.S. Navy's NC-4 transatlantic flight ; culminating in May 1927 with Charles Lindbergh 's solo trans-Atlantic flight in the Spirit of St. Louis spurring ever-longer flight attempts. Airplanes had a presence in the major battles of World War II. They were an essential component of military strategies, such as the German Blitzkrieg or the American and Japanese aircraft carrier campaigns of
816-420: A beam reach is called a close reach . At 135° off the wind, a craft is on a broad reach . At 180° off the wind (sailing in the same direction as the wind), a craft is running downwind . A given point of sail (beating, close reach, beam reach, broad reach, and running downwind) is defined in reference to the true wind —the wind felt by a stationary observer. The motive power , and thus appropriate position of
918-412: A circle, starting with 0° directly into the wind. For many sailing craft 45° on either side of the wind is a no-go zone, where a sail is unable to mobilize power from the wind. Sailing on a course as close to the wind as possible—approximately 45°—is termed beating , a point of sail when the sails are close-hauled . At 90° off the wind, a craft is on a beam reach . The point of sail between beating and
1020-411: A combination of winglets and increased span to carry the additional load. The winglets increased the 747-400's range by 3.5% over the 747-300, which is otherwise aerodynamically identical but has no winglets. The 747-400D variant lacks the wingtip extensions and winglets included on other 747-400s since winglets would provide minimal benefits on short-haul routes while adding extra weight and cost, although
1122-417: A few degrees to one side of its course, necessitating sailing with the sail sheeted in for most points of sail. On conventional sail boats, the sails are set to create lift for those points of sail where it's possible to align the leading edge of the sail with the apparent wind. For a sailboat, point of sail significantly affects the lateral force to which the boat is subjected. The higher the boat points into
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#17328594598631224-497: A given bending moment, a near-vertical winglet offers a greater drag reduction compared to a horizontal span extension. Whitcomb's designs were flight-tested in 1979–80 by a joint NASA/Air Force team, using a KC-135 Stratotanker based at the Dryden Flight Research Center . A Lockheed L-1011 and McDonnell Douglas DC-10 were also used for testing, and the latter design was directly implemented by McDonnell Douglas on
1326-476: A given improvement in fuel efficiency correlates directly with the causal increase in the aircraft's lift-to-drag ratio. The initial concept dates back to 1897, when English engineer Frederick W. Lanchester patented wing end-plates as a method for controlling wingtip vortices. In the United States, Scottish-born engineer William E. Somerville patented the first functional winglets in 1910. Somerville installed
1428-416: A glider) made out of paper or paperboard. Model glider aircraft are models of aircraft using lightweight materials such as polystyrene and balsa wood . Designs range from simple glider aircraft to accurate scale models , some of which can be very large. Glide bombs are bombs with aerodynamic surfaces to allow a gliding flight path rather than a ballistic one. This enables stand-off aircraft to attack
1530-400: A glider. Gliders and sailplanes that are used for the sport of gliding have high aerodynamic efficiency. The highest lift-to-drag ratio is 70:1, though 50:1 is common. After take-off, further altitude can be gained through the skillful exploitation of rising air. Flights of thousands of kilometers at average speeds over 200 km/h have been achieved. One small-scale example of a glider
1632-439: A greater angle, dispensing with the winglets entirely. The Schempp-Hirth Discus-2 and Schempp-Hirth Duo Discus use non-planar wingtips. Tamarack Aerospace Group, a company founded in 2010 by aerospace structural engineer Nicholas Guida, has patented an Active Technology Load Alleviation System (ATLAS), a modified version of a wingtip device. The system uses Tamarack Active Camber Surfaces (TACS) to aerodynamically "switch off"
1734-526: A limited propulsion system for takeoff, or to extend flight duration. As is the case with planes, gliders come in diverse forms with varied wings, aerodynamic efficiency, pilot location, and controls. Large gliders are most commonly born aloft by a tow-plane or by a winch . Military gliders have been used in combat to deliver troops and equipment, while specialized gliders have been used in atmospheric and aerodynamic research. Rocket-powered aircraft and spaceplanes have made unpowered landings similar to
1836-484: A marked dihedral angle . This became a standard feature of the approximately 320 completed He 162A jet fighters built, with hundreds more He 162A airframes going unfinished by V-E Day . The term "winglet" was previously used to describe an additional lifting surface on an aircraft, like a short section between wheels on fixed undercarriage. Richard Whitcomb's research in the 1970s at NASA first used winglet with its modern meaning referring to near-vertical extension of
1938-522: A production aircraft, either civilian or military. Learjet developed the winglet design without NASA assistance. Although the Model 28 was intended to be a prototype experimental aircraft, performance was such that it resulted in a production commitment from Learjet. Flight tests showed that the winglets increased range by about 6.5 percent and improved directional stability. Learjet's application of winglets to production aircraft continued with newer models including
2040-414: A reach. A variety of high-performance sailing craft sail fastest on a broad reach with the sails close-hauled at speeds several times the true windspeed. Depending on the angle of the true wind with respect to the course sailed, a reach may be close , beam , or broad , as follows: Sailing with the wind or running before the wind , the sails generate power primarily through drag (like a parachute) with
2142-399: A same-length winglet, its bending moment is greater. A 3 ft (91 cm) winglet gives the performance gain of a 2 ft (61 cm) span increase but has the bending force of a 1 ft (30 cm) span increase. Raked wingtips offer several weight-reduction advantages relative to simply extending the conventional main wingspan . At high load-factor structural design conditions,
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#17328594598632244-414: A similar design to the 737 MAX wingtip device known as the split scimitar winglet, with United Airlines as the launch customer. The Boeing 737 MAX uses a new type of wingtip device. Resembling a three-way hybrid of a winglet, wingtip fence, and raked wingtip, Boeing claims that this new design should deliver an additional 1.5% improvement in fuel economy over the 10-12% improvement already expected from
2346-581: A small improvement in efficiency is a significant competitive advantage. Many non-competition pilots fitted winglets for handling benefits such as increased roll rate and roll authority and reduced tendency for wing tip stall . The benefits are notable, because sailplane winglets must be removable to allow the glider to be stored in a trailer , so they are usually installed only at the pilot's preference. The Glaser-Dirks DG-303 , an early glider derivative design, incorporating winglets as factory standard equipment. Aviation Partners developed and flight tested
2448-520: A small, nearly right-angle, transition area. Once the performance of the winglet itself was optimized, attention was turned to the transition between the wing and winglet. A common application was tapering the transition area from the wing tip chord to the winglet chord and raking the transition area back, to place the winglet in the optimal position. If the tapered portion was canted upward, the winglet height could also be reduced. Eventually, designers employed multiple non-planar sections, each canting up at
2550-626: A spinning shaft generates lift), and ornithopters (in which the wings oscillate to generate lift). 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. Gliding fixed-wing aircraft, including free-flying gliders and tethered kites , can use moving air to gain altitude. Powered fixed-wing aircraft (airplanes) that gain forward thrust from an engine include powered paragliders , powered hang gliders and ground effect vehicles . Most fixed-wing aircraft are operated by
2652-454: A stop—it will be "in irons". The recognized points of sail are judged relative to the true wind direction. They include: The range of directions into the wind, where a sailing craft cannot sail is called the no-go zone . A sailing craft cannot sail directly into the wind, nor on a course that is too close to the direction from which the wind is blowing, because the sails cannot generate lift in this no-go zone. A craft passing through
2754-635: A streamlined fuselage and long narrow wings incorporating a high aspect ratio . Single-seat and two-seat gliders are available. Initially, training was done by short "hops" in primary gliders , which have no cockpit and minimal instruments. Since shortly after World War II, training is done in two-seat dual control gliders, but high-performance two-seaters can make long flights. Originally skids were used for landing, later replaced by wheels, often retractable. Gliders known as motor gliders are designed for unpowered flight, but can deploy piston , rotary , jet or electric engines . Gliders are classified by
2856-465: A successful passenger-carrying glider in 1853. In 1856, Frenchman Jean-Marie Le Bris made the first powered flight, had his glider L'Albatros artificiel towed by a horse along a beach. In 1884, American John J. Montgomery made controlled flights in a glider as a part of a series of gliders he built between 1883 and 1886. Other aviators who made similar flights at that time were Otto Lilienthal , Percy Pilcher , and protégés of Octave Chanute . In
2958-452: A target from a distance. A kite is a tethered aircraft held aloft by wind that blows over its wing(s). High pressure below the wing deflects the airflow downwards. This deflection generates horizontal drag in the direction of the wind. The resultant force vector from the lift and drag force components is opposed by the tension of the tether . Kites are mostly flown for recreational purposes, but have many other uses. Early pioneers such as
3060-405: A technical paper published in 1952 that called for drooped wingtips whose pointed rear tips focused the resulting wingtip vortex away from the upper wing surface. Drooped wingtips are often called "Hoerner tips" in his honor. Gliders and light aircraft have made use of Hoerner tips for many years. The earliest-known implementation of a Hoerner-style downward-angled "wingtip device" on a jet aircraft
3162-409: A vessel sails alternately in the directions 45° from the downwind direction, it will sail √ 2 (≈1.4) times farther than it would if it sailed dead downwind. However, as long as it can sail faster than 1.4 times its dead downwind speed, the indirect route will allow it to arrive at a chosen point sooner. Craft running downwind increase power from the sails by increasing total area presented to
Wingtip device - Misplaced Pages Continue
3264-402: A wing , relying on lift to propel the craft forward on a course as close to the wind as the sail can provide lift. This point of sail lets the sailing craft travel upwind, diagonally to the wind direction. The smaller the angle between the direction of the true wind and the course of the sailing craft, the higher the craft is said to point . A craft that can point higher or sail faster upwind
3366-423: A wing without greatly increasing the wingspan . Extending the span would lower lift-induced drag , but would increase parasitic drag and would require boosting the strength and weight of the wing. At some point, there is no net benefit from further increased span. There may also be operational considerations that limit the allowable wingspan (e.g., available width at airport gates ). Wingtip devices help prevent
3468-437: A winglet-equipped 15-meter class limited wingspan glider, exceeding the highest speed in the unlimited span Open Class , an exceptional result. Masak went on to win the 1993 U.S. 15 Meter Nationals gliding competition, using winglets on his prototype Masak Scimitar . The Masak winglets were originally retrofitted to production sailplanes, but within 10 years of their introduction, most high-performance gliders were equipped from
3570-404: Is a lightweight, free-flying, foot-launched glider with no rigid body. The pilot is suspended in a harness below a hollow fabric wing whose shape is formed by its suspension lines. Air entering vents in the front of the wing and the aerodynamic forces of the air flowing over the outside power the craft. Paragliding is most often a recreational activity. A paper plane is a toy aircraft (usually
3672-419: Is a zone of approximately 45° on either side of the true wind, where a sail cannot generate lift, called the "no-go zone". The angle encompassed by the no-go zone depends on the airfoil efficiency of the craft's sails and the craft's lateral resistance on the surface (from hydrofoils , outriggers , or a keel in the water, runners on ice , or wheels on land ). A craft remaining in its no-go zone will slow to
3774-408: Is capable of taking off and landing (alighting) on water. Seaplanes that can also operate from dry land are a subclass called amphibian aircraft . Seaplanes and amphibians divide into two categories: float planes and flying boats . Many forms of glider may include a small power plant. These include: A ground effect vehicle (GEV) flies close to the terrain, making use of the ground effect –
3876-442: Is now at the tip of the winglet. The fuel economy improvement from winglets increases with the mission length. Blended winglets allow a steeper angle of attack reducing takeoff distance. Richard T. Whitcomb , an engineer at NASA 's Langley Research Center , further developed Hoerner's concept in response to the sharp increase in the cost of fuel after the 1973 oil crisis . With careful aeronautical design he showed that, for
3978-527: Is often swept back like a raked wingtip and may also be combined with a winglet . A winglet is also a special case of a non-planar wingtip. Aircraft designers employed mostly planar wing designs with simple dihedral after World War II, prior to the introduction of winglets. With the wide acceptance of winglets in new sailplane designs of the 1990s, designers sought to further optimize the aerodynamic performance of their wingtip designs. Glider winglets were originally retrofitted directly to planar wings, with only
4080-480: Is on the Boeing 747 Shuttle Carrier Aircraft . Located on the 747's horizontal stabilizers, the devices increase the tailplane's effectiveness under the weight of the Space Shuttle orbiter , though these were more for directional stability than for drag reduction. Learjet exhibited the prototype Learjet 28 at the 1977 National Business Aviation Association convention. It employed the first winglets ever used on
4182-427: Is said to be more weatherly . Pinching occurs as a craft's point of sail approaches the no-go zone and its speed falls off sharply. In order to sail upwind, sailing craft must zig-zag across the direction of the oncoming wind, called beating to windward . The higher a vessel that can point into the wind, the shorter its "course made good" to an upwind destination. Beating upwind, a vessel alternates between having
Wingtip device - Misplaced Pages Continue
4284-526: Is sport and recreation. Gliders were developed in the 1920s for recreational purposes. As pilots began to understand how to use rising air, sailplane gliders were developed with a high lift-to-drag ratio . These allowed the craft to glide to the next source of " lift ", increasing their range. This gave rise to the popular sport of gliding . Early gliders were built mainly of wood and metal, later replaced by composite materials incorporating glass, carbon or aramid fibers. To minimize drag , these types have
4386-645: Is the paper airplane. An ordinary sheet of paper can be folded into an aerodynamic shape fairly easily; its low mass relative to its surface area reduces the required lift for flight, allowing it to glide some distance. Gliders and sailplanes share many design elements and aerodynamic principles with powered aircraft. For example, the Horten H.IV was a tailless flying wing glider, and the delta-winged Space Shuttle orbiter glided during its descent phase. Many gliders adopt similar control surfaces and instruments as airplanes. The main application of modern glider aircraft
4488-732: The A320neo , the A330neo and the A350 . They are also offered as a retrofit option. Raked wingtips, where the tip has a greater wing sweep than the rest of the wing, are featured on some Boeing Commercial Airplanes to improve fuel efficiency , takeoff and climb performance. Like winglets, they increase the effective wing aspect ratio and diminish wingtip vortices , decreasing lift-induced drag. In testing by Boeing and NASA, they reduce drag by as much as 5.5%, compared to 3.5% to 4.5% for conventional winglets. While an increase in span would be more effective than
4590-500: The Citation X . Conventional winglets were fitted to Rutan's Rutan Voyager , the first aircraft to circumnavigate the world without refueling in 1986. The aircraft's wingtips were damaged, however, when they dragged along the runway during takeoff, removing about 1 foot (30 cm) from each wingtip, so the flight was made without benefit of winglets. The average commercial jet sees a 4-6 percent increase in fuel efficiency and as much as
4692-544: The FAI for competitions into glider competition classes mainly on the basis of wingspan and flaps. A class of ultralight sailplanes, including some known as microlift gliders and some known as airchairs, has been defined by the FAI based on weight. They are light enough to be transported easily, and can be flown without licensing in some countries. Ultralight gliders have performance similar to hang gliders , but offer some crash safety as
4794-993: The Learjet 55 , 31 , 60 , 45 , and Learjet 40 . Gulfstream Aerospace explored winglets in the late 1970s and incorporated winglets in the Gulfstream III , Gulfstream IV and Gulfstream V . The Gulfstream V range of 6,500 nmi (12,000 km) allows nonstop routes such as New York–Tokyo, it holds over 70 world and national flight records. The Rutan combined winglets-vertical stabilizer appeared on his Beechcraft Starship business aircraft design that first flew in 1986. Winglets are also applied to other business aircraft, reducing take-off distance to operate from smaller airports, and allowing higher cruise altitudes. Along winglets on new designs, aftermarket vendors developed retrofits. Winglet Technology, LLC of Wichita, Kansas should have tested its elliptical winglets designed to increase payload-range on hot and high departures to retrofit
4896-725: The Piper PA-42 Cheyenne and several other fixed-wing aircraft types by bending the blade tips back at a 90-degree angle to get the same thrust from a reduced diameter propeller disk; the reduced propeller tip speed reduces noise, according to the manufacturer. Modern scimitar propellers have increased sweepback at the tips, resembling a raked tip on an aircraft wing. Some ceiling fans have wingtip devices. Fan manufacturer Big Ass Fans has claimed that their Isis fan, equipped with wingtip devices, has superior efficiency. However, for certain high-volume, low-speed designs, wingtip devices may not improve efficiency. Another application of
4998-498: The Wright Brothers and J.W. Dunne sometimes flew an aircraft as a kite in order to confirm its flight characteristics, before adding an engine and flight controls. Kites have been used for signaling, for delivery of munitions , and for observation , by lifting an observer above the field of battle, and by using kite aerial photography . Points of sail The principal points of sail roughly correspond to 45° segments of
5100-521: The Wright Flyer III was capable of fully controllable, stable flight for substantial periods. In 1906, Brazilian inventor Alberto Santos Dumont designed, built and piloted an aircraft that set the first world record recognized by the Aéro-Club de France by flying the 14 bis 220 metres (720 ft) in less than 22 seconds. The flight was certified by the FAI. The Bleriot VIII design of 1908
5202-452: The wing tips . The upward angle (or cant ) of the winglet, its inward or outward angle (or toe ), as well as its size and shape are critical for correct performance and are unique in each application. The wingtip vortex, which rotates around from below the wing, strikes the cambered surface of the winglet, generating a force that angles inward and slightly forward, analogous to a sailboat sailing close hauled . The winglet converts some of
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#17328594598635304-411: The yardarms , to create a larger sail area for points of sail, ranging from downwind to a close reach. Sails for a fore-and-aft rig and a square rig in use downwind True wind ( V T ) combines with the sailing craft's velocity ( V B ) to be the apparent wind velocity ( V A ); the air velocity experienced by instrumentation or crew on a moving sailing craft. Apparent wind velocity provides
5406-479: The -400D may be converted to the long-range version if needed. Winglets are preferred for Boeing derivative designs based on existing platforms, because they allow maximum re-use of existing components. Newer designs are favoring increased span, other wingtip devices or a combination of both, whenever possible. The Ilyushin Il-96 was the first Russian and modern jet to feature winglets in 1988. The Bombardier CRJ-100 /200
5508-455: The 1890s, Lawrence Hargrave conducted research on wing structures and developed a box kite that lifted the weight of a man. His designs were widely adopted. He also developed a type of rotary aircraft engine, but did not create a powered fixed-wing aircraft. Sir Hiram Maxim built a craft that weighed 3.5 tons, with a 110-foot (34-meter) wingspan powered by two 360-horsepower (270-kW) steam engines driving two propellers. In 1894, his machine
5610-462: The 18th and 19th centuries kites were used for scientific research. Around 400 BC in Greece , Archytas was reputed to have designed and built the first self-propelled flying device, shaped like a bird and propelled by a jet of what was probably steam, said to have flown some 200 m (660 ft). This machine may have been suspended during its flight. One of the earliest attempts with gliders
5712-502: The 737 MAX. In 1987, mechanical engineer Peter Masak called on aerodynamicist Mark D. Maughmer , an associate professor of aerospace engineering at the Pennsylvania State University , about designing winglets to improve performance on his 15-meter (49 ft) wingspan racing sailplane . Others had attempted to apply Whitcomb's winglets to gliders before, and they did improve climb performance, but this did not offset
5814-527: The Pacific. Military gliders were developed and used in several campaigns, but were limited by the high casualty rate encountered. The Focke-Achgelis Fa 330 Bachstelze (Wagtail) rotor kite of 1942 was notable for its use by German U-boats . Before and during the war, British and German designers worked on jet engines . The first jet aircraft to fly, in 1939, was the German Heinkel He 178 . In 1943,
5916-506: The United States and Canada in 1919. The so-called Golden Age of Aviation occurred between the two World Wars, during which updated interpretations of earlier breakthroughs. Innovations include Hugo Junkers ' all-metal air frames in 1915 leading to multi-engine aircraft of up to 60+ meter wingspan sizes by the early 1930s, adoption of the mostly air-cooled radial engine as a practical aircraft power plant alongside V-12 liquid-cooled aviation engines, and longer and longer flights – as with
6018-414: The apparent wind perpendicular to its surface, acts substantially like a parachute with the drag on the sail as the dominant force. As a sailing craft transitions from close-hauled to running downwind, the lifting force decreases and the drag force increases. At the same time, the resistance to sidewards motion needed to keep the craft on course also decreases, along with the sideways tipping force. There
6120-447: The bending moment on the inboard wing. However, the relative aft-movement of the center of pressure accentuates flutter . Raked wingtips are installed on the Boeing 767 -400ER (first flight on October 9, 1999), all generations of Boeing 777 (June 12, 1994) including the upcoming 777X , the 737-derived Boeing P-8 Poseidon (25 April 2009), all variants of the Boeing 787 (December 15, 2009) (the cancelled Boeing 787-3 would have had
6222-534: The derivative MD-11 , which was rolled out in 1990. In May 1983, a high school student at Bowie High School in Maryland won a grand prize at the 34th International Science and Engineering Fair in Albuquerque, New Mexico for the result of his research on wingtip devices to reduce drag. The same month, he filed a U.S. patent for "wingtip airfoils", published in 1986. NASA's most notable application of wingtip devices
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#17328594598636324-419: The devices on his early biplane and monoplane designs. Vincent Burnelli received US Patent no: 1,774,474 for his "Airfoil Control Means" on August 26, 1930. Simple flat end-plates did not cause a reduction in drag, because the increase in profile drag was greater than the decrease in induced drag. Following the end of World War II, Dr. Sighard F. Hoerner was a pioneer researcher in the field, having written
6426-434: The effects of the wingtip device when the aircraft is experiencing high-g events such as large gusts or severe pull-ups. TACS are movable panels, similar to flaps or ailerons , on the trailing edge of the wing extension. The system is controlled by the aircraft's electrical system and a high-speed servo which is activated when the aircraft senses an oncoming stress event, essentially simulating an actuating wingtip. However,
6528-416: The efficiency of a sailing craft's sails and its resistance to sideways motion in the water (using a keel or foils) on ice or on land, typically at an angle between 30 and 50 degrees from the wind. A craft stopped in the no-go zone is said to be in irons. A square-rigged vessel in irons by accident is taken aback with the sails blown against the mast or laid aback if deliberate. In either case,
6630-463: The factory with winglets or other wingtip devices. It took over a decade for winglets to first appear on a production airliner, the original application that was the focus of the NASA development. Yet, once the advantages of winglets were proven in competition, adoption was swift with gliders. The point difference between the winner and the runner-up in soaring competition is often less than one percent, so even
6732-693: The first operational jet fighter, the Messerschmitt Me 262 , went into service with the German Luftwaffe . Later in the war the British Gloster Meteor entered service, but never saw action – top air speeds for that era went as high as 1,130 km/h (700 mph), with the early July 1944 unofficial record flight of the German Me 163B V18 rocket fighter prototype. In October 1947, the Bell X-1
6834-466: The first shipset was installed on 14 February 2001 and entered revenue service with Hapag-Lloyd Flug on 8 May 2001. The Aviation Partners/Boeing 8 ft (2.4 m) extensions decrease fuel consumption by 4% for long-range flights and increase range by 130 or 200 nmi (240 or 370 km) for the 737-800 or the derivative Boeing Business Jet as standard. Also offered for the 737 Classic , many operators have retrofitted their fleets with these for
6936-479: The flow around the wingtip of higher pressure air under the wing flowing to the lower pressure surface on top at the wingtip, which results in a vortex caused by the forward motion of the aircraft. Winglets also reduce the lift-induced drag caused by wingtip vortices and improve lift-to-drag ratio . This increases fuel efficiency in powered aircraft and increases cross-country speed in gliders , in both cases increasing range . U.S. Air Force studies indicate that
7038-420: The following wind, sometimes by putting out sails that adapt well to the purpose, such as a spinnaker on a fore-and-aft rigged vessel. Another technique is to place the jib to windward (opposite to the main sail)—called "wing on wing" or one of several other terms—for a fore-and-aft vessel going dead downwind. In light winds, certain square-rigged vessels may set studding sails , sails that extend outwards from
7140-611: The fuel savings. Aviation Partners Boeing also offers blended winglets for the 757 and 767-300ER . In 2006 Airbus tested two candidate blended winglets, designed by Winglet Technology and Airbus for the Airbus A320 family . In 2009 Airbus launched its "Sharklet" blended winglet, designed to enhance the payload-range of its A320 family and reduce fuel burn by up to 4% over longer sectors. This corresponds to an annual CO 2 reduction of 700 tonnes per aircraft. The A320s fitted with Sharklets were delivered beginning in 2012. They are used on
7242-579: The ground surface during taxiing , takeoff , and hover , these devices can reduce damage from dirt and small stones picked up in the vortices. The main rotor blades of the AgustaWestland AW101 (formerly the EH101) have a distinctive tip shape; pilots have found that this rotor design alters the downwash field and reduces brownout which limits visibility in dusty areas and leads to accidents. Hartzell Propeller developed their "Q-tip" propeller used on
7344-559: The interaction between the wings and the surface. Some GEVs are able to fly higher out of ground effect (OGE) when required – these are classed as powered fixed-wing aircraft. A glider is a heavier-than-air craft whose free flight does not require an engine. A sailplane is a fixed-wing glider designed for soaring – gaining height using updrafts of air and to fly for long periods. Gliders are mainly used for recreation but have found use for purposes such as aerodynamics research, warfare and spacecraft recovery. Motor gliders are equipped with
7446-490: The motive power for the sails on any given point of sail. The apparent wind is equal to the true wind velocity for a stopped craft; it may be faster than the true wind speed on some points of sail, or it may be slower e.g. when a sailing craft sails dead downwind. Sailing craft A is close-hauled. Sailing craft B is on a beam reach. Sailing craft C is on a broad reach. Boat velocity (in black) generates an equal and opposite apparent wind component (not shown), which adds to
7548-400: The no-go zone to change tacks from one side to the other, must maintain momentum until its sails can draw power on the other side. If it remains in the no-go zone, it will slow to a stop and be in irons . This is called missing stays . To recover, that craft typically must return to its original tack and pick up sufficient speed to complete the maneuver. The span of the no-go zone depends on
7650-570: The otherwise-wasted energy in the wingtip vortex to an apparent thrust . This small contribution can be worthwhile over the aircraft's lifetime, provided the benefit offsets the cost of installing and maintaining the winglets. Another potential benefit of winglets is that they reduce the intensity of wake vortices . Those trail behind the plane and pose a hazard to other aircraft. Minimum spacing requirements between aircraft operations at airports are largely dictated by these factors. Aircraft are classified by weight (e.g. "Light", "Heavy", etc.) because
7752-458: The parasitic drag penalty in high-speed cruise. Masak was convinced it was possible to overcome this hurdle. By trial and error, they ultimately developed successful winglet designs for gliding competitions , using a new PSU–90–125 airfoil , designed by Maughmer specifically for the winglet application. At the 1991 World Gliding Championships in Uvalde, Texas , the trophy for the highest speed went to
7854-693: The pilot can strap into an upright seat within a deform-able structure. Landing is usually on one or two wheels which distinguishes these craft from hang gliders. Most are built by individual designers and hobbyists. Military gliders were used during World War II for carrying troops ( glider infantry ) and heavy equipment to combat zones. The gliders were towed into the air and most of the way to their target by transport planes, e.g. C-47 Dakota , or by one-time bombers that had been relegated to secondary activities, e.g. Short Stirling . The advantage over paratroopers were that heavy equipment could be landed and that troops were quickly assembled rather than dispersed over
7956-414: The pilot is suspended in a harness suspended from the air frame , and exercises control by shifting body weight in opposition to a control frame. Hang gliders are typically made of an aluminum alloy or composite -framed fabric wing. Pilots can soar for hours, gain thousands of meters of altitude in thermal updrafts, perform aerobatics, and glide cross-country for hundreds of kilometers. A paraglider
8058-401: The sails, is determined by the apparent wind : the wind relative to an observer on the sailing craft. The apparent wind is the combined effect of the velocities of the true wind and of the sailing craft. A sail with the airflow parallel to its surface, while angled into the apparent wind, acts substantially like a wing with lift as a force acting perpendicular to its surface. A sail with
8160-404: The same principle was introduced to the keel of the "America's Cup"- winning Australian yacht Australia II of 1982, designed by Ben Lexcen . Fixed-wing aircraft A fixed-wing aircraft is a heavier-than-air aircraft , such as an airplane , which is capable of flight using aerodynamic lift . Fixed-wing aircraft are distinct from rotary-wing aircraft (in which a rotor mounted on
8262-445: The smaller chords of the wingtip are subjected to less load, and they result in less induced loading on the outboard main wing. Additionally, the leading-edge sweep results in the center of pressure being located farther aft than for simple extensions of the span of conventional main wings. At high load factors, this relative aft location of the center of pressure causes the raked wingtip to be twisted more leading-edge down, reducing
8364-505: The stopped vessel will be blown backwards, which with proper positioning of the rudder allows the vessel to point outside the no-go zone and resume forward motion, once the sails can draw power. Iceboats are often parked in irons with a brake applied to the ice to prevent motion. To commence sailing, the craft is guided to one side and boarded, once the sail can draw power. A sailing craft is said to be sailing close-hauled when its sails are trimmed in tightly and are acting substantially like
8466-409: The surface of the wing. Wingtip vortices create turbulence, originating at the leading edge of the wingtip and propagating backwards and inboard. This turbulence 'delaminates' the airflow over a small triangular section of the outboard wing, which destroys lift in that area. The fence/winglet drives the area where the vortex forms upward away from the wing surface, since the center of the resulting vortex
8568-420: The true wind directly from behind the sailing craft. A sailing craft running more downwind than a broad reach cannot attain a speed faster than the true wind. However, higher-performance sailing craft achieve a higher velocity made good downwind, by sailing on whatever broad reach is most efficient on that particular craft, and jibing as needed. The longer course is offset by the faster speed. For instance, if
8670-413: The true wind to become apparent wind. The speed of sailboats through the water is limited by the resistance that results from hull drag in the water. Ice boats typically have the least resistance to forward motion of any sailing craft; consequently, a sailboat experiences a wider range of apparent wind angles than does an ice boat, whose speed is typically great enough to have the apparent wind coming from
8772-505: The use of aircraft as weapons and observation platforms. The earliest known aerial victory with a synchronized machine gun -armed fighter aircraft occurred in 1915, flown by German Luftstreitkräfte Lieutenant Kurt Wintgens . Fighter aces appeared; the greatest (by number of air victories) was Manfred von Richthofen . Alcock and Brown crossed the Atlantic non-stop for the first time in 1919. The first commercial flights traveled between
8874-417: The vortex strength grows with the aircraft lift coefficient , and thus, the associated turbulence is greatest at low speed and high weight, which produced a high angle of attack . Winglets and wingtip fences also increase efficiency by reducing vortex interference with laminar airflow near the tips of the wing, by 'moving' the confluence of low-pressure (over wing) and high-pressure (under wing) air away from
8976-482: The wind come on the port and starboard sides (the port and starboard tack). Changing from one tack to the other, by steering through the wind direction, is called tacking , or going about . A craft sailing with the true wind on its side (within limits) is reaching . Wind is flowing over the surface of the sail, creating lift (like a wing) to propel the craft. Because lift is more powerful than drag on this point of sail, sailing craft achieve their highest speeds on
9078-423: The wind, the stronger the lateral force, which results in both increased leeway and heeling. Leeway, the effect of the boat moving sideways through the water, can be counteracted by a keel or other underwater foils, including daggerboard, centerboard, skeg and rudder. Lateral force also induces heeling in a sailboat, which is resisted by the shape and configuration of the hull (or hulls, in the case of catamarans) and
9180-519: The wing/winglet junction. A sharp interior angle in this region can interact with the boundary layer flow causing a drag inducing vortex, negating some of the benefit of the winglet. Seattle -based Aviation Partners develops blended winglets as retrofits for the Gulfstream II , Hawker 800 and the Falcon 2000 . On February 18, 2000, blended winglets were announced as an option for the Boeing 737-800 ;
9282-977: The wingtip itself is fixed and the TACS are the only moving part of the wingtip system. Tamarack first introduced ATLAS for the Cessna Citation family aircraft, and it has been certified for use by the Federal Aviation Administration and European Union Aviation Safety Agency . There has been research into actuating wingtip devices, including a filed patent application, though no aircraft currently uses this feature as described. The XB-70 Valkyrie 's wingtips were capable of drooping downward in flight, to facilitate Mach 3 flight using waveriding . Wingtip devices are also used on rotating propeller , helicopter rotor , and wind turbine blades to reduce drag, reduce diameter, reduce noise and/or improve efficiency. By reducing aircraft blade tip vortices interacting with
9384-568: The world. Some of the hundreds of versions found other purposes, like the AC-47 , a Vietnam War era gunship, which is still used in the Colombian Air Force . An airplane (aeroplane or plane) is a powered fixed-wing aircraft propelled by thrust from a jet engine or propeller . Planes come in many sizes, shapes, and wing configurations. Uses include recreation, transportation of goods and people, military, and research. A seaplane (hydroplane)
9486-421: Was an early aircraft design that had the modern monoplane tractor configuration . It had movable tail surfaces controlling both yaw and pitch, a form of roll control supplied either by wing warping or by ailerons and controlled by its pilot with a joystick and rudder bar. It was an important predecessor of his later Bleriot XI Channel -crossing aircraft of the summer of 1909. World War I served initiated
9588-441: Was by 11th-century monk Eilmer of Malmesbury , which failed. A 17th-century account states that 9th-century poet Abbas Ibn Firnas made a similar attempt, though no earlier sources record this event. In 1799, Sir George Cayley laid out the concept of the modern airplane as a fixed-wing machine with systems for lift, propulsion, and control. Cayley was building and flying models of fixed-wing aircraft as early as 1803, and built
9690-400: Was developed to investigate alternative methods of recovering spacecraft. Although this application was abandoned, publicity inspired hobbyists to adapt the flexible-wing airfoil for hang gliders. Initial research into many types of fixed-wing craft, including flying wings and lifting bodies was also carried out using unpowered prototypes. A hang glider is a glider aircraft in which
9792-539: Was during World War II. This was the so-called "Lippisch-Ohren" (Lippisch-ears), allegedly attributed to the Messerschmitt Me 163 's designer Alexander Lippisch , and first added to the M3 and M4 third and fourth prototypes of the Heinkel He 162 A Spatz jet light fighter for evaluation. This addition was done in order to counteract the dutch roll characteristic present in the original He 162 design, related to its wings having
9894-558: Was in commercial service for more than 50 years, from 1958 to 2010. The Boeing 747 was the world's largest passenger aircraft from 1970 until it was surpassed by the Airbus A380 in 2005. The most successful aircraft is the Douglas DC-3 and its military version, the C-47 , a medium sized twin engine passenger or transport aircraft that has been in service since 1936 and is still used throughout
9996-535: Was tested with overhead rails to prevent it from rising. The test showed that it had enough lift to take off. The craft was uncontrollable, and Maxim abandoned work on it. The Wright brothers ' flights in 1903 with their Flyer I are recognized by the Fédération Aéronautique Internationale (FAI), the standard setting and record-keeping body for aeronautics , as "the first sustained and controlled heavier-than-air powered flight". By 1905,
10098-635: Was the first aircraft to exceed the speed of sound, flown by Chuck Yeager . In 1948–49, aircraft transported supplies during the Berlin Blockade . New aircraft types, such as the B-52 , were produced during the Cold War . The first jet airliner , the de Havilland Comet , was introduced in 1952, followed by the Soviet Tupolev Tu-104 in 1956. The Boeing 707 , the first widely successful commercial jet,
10200-637: Was the first airliner with wingtip fences in 1985. Other Airbus models followed with the A300-600 , the A320ceo , and the A380 . Other Airbus models including the Airbus A320 Enhanced , A320neo , A350 and A330neo have blended winglets rather than wingtip fences. The Antonov An-158 uses wingtip fences. Boeing announced a new version of the 747 , the 747-400 , in 1985, with an extended range and capacity, using
10302-412: Was the first regional airliner to feature winglets in 1992. The A340 / A330 followed with canted winglets in 1993/1994. The Tupolev Tu-204 was the first narrowbody aircraft to feature winglets in 1994. The Airbus A220 (née CSeries), from 2016, has canted winglets. A blended winglet is attached to the wing with a smooth curve instead of a sharp angle and is intended to reduce interference drag at
10404-446: Was used as a message for a rescue mission. Ancient and medieval Chinese sources report kites used for measuring distances, testing the wind, lifting men, signaling, and communication for military operations. Kite stories were brought to Europe by Marco Polo towards the end of the 13th century, and kites were brought back by sailors from Japan and Malaysia in the 16th and 17th centuries. Although initially regarded as curiosities, by
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