The Blériot VII was an early French aeroplane built by Louis Blériot .
75-477: Following the success with the tandem wing configuration of the Blériot VI , he continued this line of development. The rear wing of his new design was about half the span of the forward wing, a step towards the configuration that would later be adopted as the basis for the vast majority of aircraft. The tail surfaces could be moved together, to act as elevators , or independently to act as ailerons : one of
150-441: A hovercraft . A ground-effect vehicle needs some forward velocity to produce lift dynamically, and the principal benefit of operating a wing in ground effect is to reduce its lift-dependent drag . The basic design principle is that the closer the wing operates to an external surface such as the ground, when it is said to be in ground effect , the less drag it experiences. An airfoil passing through air increases air pressure on
225-789: A 50-seat passenger GEV named the WSH-500. in 2013 Estonian transport company Sea Wolf Express planned to launch passenger service in 2019 between Helsinki and Tallinn , a distance of 87 km taking only half an hour, using a Russian-built ekranoplan. The company ordered 15 ekranoplans with maximum speed of 185 km/h and capacity of 12 passengers, built by Russian RDC Aqualines. In 2021 Brittany Ferries announced that they were looking into using REGENT (Regional Electric Ground Effect Naval Transport) ground effect craft " seagliders " for cross English Channel services. Southern Airways Express also placed firm orders for seagliders with intent to operate them along Florida's east coast. Around mid-2022,
300-427: A GEV, as compared to an aircraft of similar capacity, will improve its fuel efficiency and, up to a point, its speed. GEVs are also much faster than surface vessels of similar power, because they avoid drag from the water. On the water the aircraft-like construction of GEVs increases the risk of damage in collisions with surface objects. Furthermore, the limited number of egress points make it more difficult to evacuate
375-472: A craft was soon recognized, and Alexeyev received support and financial resources from Soviet leader Nikita Khrushchev . Some manned and unmanned prototypes were built, ranging up to eight tonnes in displacement . This led to the development of a 550-tonne military ekranoplan of 92 m (302 ft) length. The craft was dubbed the Caspian Sea Monster by U.S. intelligence experts, after
450-479: A full-sized example at the end of 1912. Experimental tandem-wing aircraft continued to be built after World War I. The Caproni Ca.60 prototype flying boat comprised a long passenger-carrying hull to which were attached in tandem three stacks of triplane wings from the successful Ca.4 line of heavy bombers and airliners, earning it the nickname "Capronissimo". However it broke up on its first attempted takeoff in 1921. The first fully controllable tandem-wing type
525-643: A gulled forward wing and twin fins on the tips of the low-set and slightly shorter-span rear wing. He first built two examples of a smaller aerodynamic test aircraft, the Delanne 20-T , which flew in 1938. The Arsenal de l'Aéronautique then constructed a prototype fighter, the Arsenal-Delanne 10 . It was completed and test-flown after the German invasion of France, and was then taken to Germany for further testing. Meanwhile Westland Aircraft were considering
600-543: A huge, unknown craft was spotted on satellite reconnaissance photos of the Caspian Sea area in the 1960s. With its short wings, it looked airplane-like in planform, but would probably be incapable of flight. Although it was designed to travel a maximum of 3 m (10 ft) above the sea, it was found to be most efficient at 20 m (66 ft), reaching a top speed of 300–400 knots (560–740 km/h) in research flights. The Soviet ekranoplan program continued with
675-516: A modification of the Lysander light observation and liaison aircraft, by adding a rear gun turret to give it some protection from attack. The Lysander already had a suitable main wing, so to support the weight of the turret Westland thought of adding a Delanne-type rear wing. By now hostilities had started but France had not yet fallen. Chief Designer W. E. W. "Teddy" Petter and Chief Test Pilot Harald Penrose flew to Paris, where Penrose flew one of
750-474: A much higher speed. A GEV is sometimes characterized as a transition between a hovercraft and an aircraft , although this is not correct as a hovercraft is statically supported upon a cushion of pressurized air from an onboard downward-directed fan. Some GEV designs, such as the Russian Lun and Dingo , have used forced blowing under the wing by auxiliary engines to increase the high pressure area under
825-727: A need for reliable navigation. Minister Ustinov died in 1984, and the new Minister of Defence, Marshal Sokolov , cancelled funding for the program. Only three operational Orlyonok -class ekranoplans (with revised hull design) and one Lun -class ekranoplan remained at a naval base near Kaspiysk . Since the dissolution of the Soviet Union , ekranoplans have been produced by the Volga Shipyard in Nizhniy Novgorod . Smaller ekranoplans for non-military use have been under development. The CHDB had already developed
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#1732790169275900-782: A previous period of nearly 10 years of research and development: Bigger concepts are: 25-seater, 32-seater, 60-seater, 80-seater and bigger up to the size of a passenger airplane. Since the 1980s GEVs have been primarily smaller craft designed for the recreational and civilian ferry markets. Germany , Russia and the United States have provided most of the activity with some development in Australia , China , Japan , Korea and Taiwan . In these countries and regions, small craft with up to ten seats have been built. Other larger designs such as ferries and heavy transports have been proposed but have not been carried to completion. Besides
975-731: A ship designer whereas Lippisch worked as an aeronautical engineer. The influence of Alexeyev and Lippisch remains noticeable in most GEVs seen today. Led by Alexeyev , the Soviet Central Hydrofoil Design Bureau ( Russian : ЦКБ СПК ) was the center of ground-effect craft development in the USSR. The vehicle came to be known as an ekranoplan ( Russian : экранопла́н , экран screen + план plane , from Russian : эффект экрана , literally screen effect , or ground effect in English). The military potential for such
1050-501: A specialist and insider of German airplane industry from 1963 and a colleague of Alexander Lippisch and Hanno Fischer, was founded with a fundamental knowledge of wing in ground effect physics, as well as results of fundamental tests under different conditions and designs having begun in 1960. For over 30 years, Jörg built and tested 15 different tandem-airfoil flairboats in different sizes and made of different materials. The following tandem-airfoil flairboat (TAF) types had been built after
1125-413: A tandem design can offer a greater range of trim conditions, and hence of centre of gravity (CG) location than other layouts, which can offer a practical solution where weight loadings and distributions may vary during operations. However a wide CG range leads to other problems, including a compatible undercarriage layout and safe stalling characteristics. The joined wing is a tandem-wing layout in which
1200-421: A tandem design each wing is smaller and the outer load is absent. This allows the wing structure to be lighter overall. In a conventional design, the fuselage is supported only in one place, with the fore and aft fuselage sections cantilevered out from it. This creates significant bending stresses. A tandem wing supports the same fuselage in two places, reducing the bending stresses. However the torsion stresses on
1275-435: A tandem wing the lift forces on the two wings are separated longitudinally, allowing them to act together to achieve stability, control and trim. The mechanisms of stability and control for a tandem wing are similar to those for the tail-first or canard layout; the distinction is mainly in the relative size of the forward surface. However, the larger trim forces available compared to a smaller tailplane or foreplane mean that
1350-485: A tandem-wing model. Four sets of wings in tandem variously provided lift and propulsion, and Burraitni's cat became the first aeronaut to fly in a tandem design. Having also flown simpler fore-and-aft tandem models of up to 14 feet (4.3 m) in span, in 1903 Samuel Pierpont Langley built a full-size tandem-wing monoplane, the Aerodrome , and launched it from the roof of a houseboat. It failed to fly. After his death
1425-422: Is a vehicle that is able to move over the surface by gaining support from the reactions of the air against the surface of the earth or water. Typically, it is designed to glide over a level surface (usually over the sea) by making use of ground effect , the aerodynamic interaction between the moving wing and the surface below. Some models can operate over any flat area such as frozen lakes or flat plains similar to
1500-592: Is a wing configuration in which a flying craft or animal has two or more sets of wings set one behind another. All the wings contribute to lift . The tandem wing is distinct from the biplane in which the wings are stacked one above another, or from the canard or "tail-first" configuration where the forward surface is much smaller and does not contribute significantly to the overall lift. In aviation, tandem wings have long been experimented with, but few designs have ever been put into production. Tandem wings in nature occur only in insects and flying fish, although in
1575-568: Is also sometimes treated as an extreme staggered biplane and referred to as the Nénandovich biplane. Interference effects between the two wings can make a tandem layout less efficient in cruise than the equivalent conventional design, however examples such as the Scaled Composites Proteus are capable of exceptional efficiency. The tandem layout creates a "slot effect" in which the front wing deflects air downwards over
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#17327901692751650-536: Is based. However, in 2005, the IMO classified the WISE or GEV under the category of ships. The International Maritime Organization recognizes three types of GEVs: At the time of writing, those classes only applied to craft carrying 12 passengers or more, and (as of 2019) there was disagreement between national regulatory agencies about whether these vehicles should be classified, and regulated, as aircraft or as boats. By
1725-501: Is dangerous because the ground is uneven and the altitude called skimming permits no freedom of maneuver. But on large-sized aircraft, over water, the question may be attempted ..." By the 1960s, the technology started maturing, in large part due to the independent contributions of Rostislav Alexeyev in the Soviet Union and German Alexander Lippisch , working in the United States . Alexeyev worked from his background as
1800-412: Is more difficult for GEVs with short production runs to overcome. For the vehicle to work, its hull needs to be stable enough longitudinally to be controllable yet not so stable that it cannot lift off the water. The bottom of the vehicle must be formed to avoid excessive pressures on landing and taking off without sacrificing too much lateral stability, and it must not create too much spray, which damages
1875-433: Is now leading the way". However, the next flight trials, on 18 December, ended with a crash: the left wheel collapsed, causing the wing to dig in and the aircraft to turn over, resulting in its destruction. Blériot escaped without serious injury, his life possibly saved by the cabane structure, which acted as a roll bar. Data from Opdycke 1990, p.49 General characteristics Tandem wing A tandem wing
1950-493: Is the classification and legislation to be applied. The International Maritime Organization has studied the application of rules based on the International Code of Safety for High-Speed Craft (HSC code) which was developed for fast ships such as hydrofoils , hovercraft, catamarans and the like. The Russian Rules for classification and construction of small type A ekranoplans is a document upon which most GEV design
2025-609: The Odonata ( dragonflies and damselflies ), Lepidoptera ( butterflies and moths ) and some Thysanoptera or Thrips . Odonata species typically have long, thin wings and can synchronise the flapping of fore and aft pairs in various different modes, allowing them to be both fast and highly manoeuvrable. By comparison the Lepidoptera have wider wings which are flapped in synchrony and may even overlap in flight, and are better suited to endurance flying. Thrips are smaller insects and
2100-528: The Smithsonian Institution sought to prove that he had flown in the weeks before the Wright brothers , and employed successful planemaker Glenn Curtiss to secretly modify the aerodrome until it could fly, as "proof" that it had flown in 1903. Curtiss added floats and made other improvements, enabling it to undertake short hops as a true waterplane in 1914. The ruse was eventually exposed, yet
2175-408: The helicopter . Unlike the hydrofoil , it does not have any contact with the surface of the water when in "flight". The ground-effect vehicle constitutes a unique class of transportation. The Boston-based (United States) company REGENT proposed an electric-powered high-wing design with a standard hull for water operations, but also incorporated fore- and aft-mounted hydrofoil units designed to lift
2250-541: The 1920s, the ground effect phenomenon was well-known, as pilots found that their airplanes appeared to become more efficient as they neared the runway surface during landing. In 1934 the US National Advisory Committee for Aeronautics issued Technical Memorandum 771, Ground Effect on the Takeoff and Landing of Airplanes , which was a translation into English of a summary of French research on
2325-481: The 20-Ts and reported favourably on its handling. The tandem Lysander was not completed until 1941, when Penrose began test flights. Although it performed flawlessly – he wrote that "here was a military prototype that needed no alteration" – it was not ordered into production. George Miles saw the tandem Lysander at RAF Boscombe Down and realised its potential as a short-span, short-take-off Naval fighter. The ensuing Miles M.35 Libellula test aircraft differed from
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2400-571: The Black Sea and Baltic Sea fleets. A few Orlyonoks served with the Soviet Navy from 1979 to 1992. In 1987, the 400-tonne Lun -class ekranoplan was built as an anti-ship missile launch platform. A second Lun , renamed Spasatel , was laid down as a rescue vessel, but was never finished. The two major problems that the Soviet ekranoplans faced were poor longitudinal stability and
2475-548: The Delanne design in having wings of approximately equal span, but with the rear wing given a longer chord and swept back. Although the design was rejected, it flew well enough to prompt development of the larger M.39B , a subscale test aircraft for the proposed M.39 high-speed bomber to meet Specification B.11/41. This time the fore wing was smaller and mounted low, while the swept rear wing was high-mounted with twin engine nacelles slung beneath. Flying in 1943 it performed well, but
2550-663: The FS-8 carried six persons. The FS-8 was to be developed by Fischer Flugmechanik for a Singapore-Australian joint venture called Flightship. Powered by a V8 Chevrolet automobile engine rated at 337 kW, the prototype made its first flight in February 2001 in the Netherlands. The company no longer exists but the prototype craft was bought by Wigetworks, a company based in Singapore and renamed as AirFish 8. In 2010, that vehicle
2625-698: The GEV in a shipyard in southern Iran. The GEV has two engines and no armament. In Singapore, Wigetworks obtained certification from Lloyd's Register for entry into class. On 31 March 2011, AirFish 8-001 became one of the first GEVs to be flagged with the Singapore Registry of Ships, one of the largest ship registries. Wigetworks partnered with National University of Singapore 's Engineering Department to develop higher capacity GEVs. Burt Rutan in 2011 and Korolev in 2015 showed GEV projects. In Korea, Wing Ship Technology Corporation developed and tested
2700-477: The Peyret glider of 1922. However the rear wing is usually placed either above or below the fore wing, in order to avoid its turbulent wake. One wing is often made a little smaller than the other, according to the details of the design. Indeed, there are no clear dividing lines between the conventional vs. tandem, or the tandem vs. canard configurations. The high-mounted fore wing and low-mounted aft wing arrangement
2775-538: The Smithsonian still sought to claim that the 1902 version had been "capable of flight". It would be many more years before they recanted. Several pioneers had long made successful gliders. In 1905 John J. Montgomery flew a tandem monoplane glider, confirming that the aerodynamic principle was sound. Powered flight followed two years later. In 1906 Louis Blériot built his third aeroplane with tandem elliptical closed wings, later modifying it as his type IV with
2850-555: The US Defense Advanced Research Projects Agency (DARPA) launched its Liberty Lifter project, with the goal of creating a low-cost seaplane that would use the ground-effect to extend its range. The program aims to carry 90 tons over 6,500 nautical miles (12,000 km), operate at sea without ground-based maintenance, all using low-cost materials. In May 2024, Ocean Glider announced a deal with UK-based investor MONTE to finance $ 145m of
2925-847: The United States Defense Advanced Research Projects Agency (DARPA) studied the Aerocon Dash 1.6 wingship . Universal Hovercraft developed a flying hovercraft, first flying a prototype in 1996. Since 1999, the company has offered plans, parts, kits and manufactured ground effect hovercraft called the Hoverwing. Iran deployed three squadrons of Bavar 2 two-seat GEVs in September 2010. This GEV carries one machine gun and surveillance gear, and incorporates features to reduce its radar signature. In October 2014, satellite images showed
3000-400: The ability of hovercraft or hydrofoils, which are closer to the water surface. Like conventional aircraft, greater power is needed for takeoff, and, like seaplanes, ground-effect vehicles must get on the step before they can accelerate to flight speed. Careful design, usually with multiple redesigns of hullforms, is required to get this right, which increases engineering costs. This obstacle
3075-417: The aerodynamics of the flapping main wing. Flying fish have enlarged pectoral fins and are capable of gliding flight, though not of true flapping flight. Some species, such as the band-wing, also have sufficiently enlarged pelvic fins , further back along their bodies, to form a tandem layout. Microraptor was a genus of tandem-winged dinosaurs , possibly only a single species. It is known only from
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3150-621: The airframe and the engines. The Russian ekranoplans show evidence of fixes for these problems in the form of multiple chines on the forward part of the hull undersides and in the forward location of the jet engines. Finally, limited utility has kept production levels low enough that it has been impossible to amortize development costs sufficiently to make GEVs competitive with conventional aircraft. A 2014 study by students at NASA's Ames Research Center claims that use of GEVs for passenger travel could lead to cheaper flights, increased accessibility and less pollution. One obstacle to GEV development
3225-616: The bomber requirement was subsequently cancelled. After WWII, interest returned to the Flying Flea's tilting forewing concept and, with its worst dangers now understood and fixed, designers have continued to develop the idea, typically still for home construction. The Curtiss-Wright X-19 of 1963 marked the entry of the tandem wing configuration into the VTOL arena, as a quadrotor convertiplane, with large tilting proprotors mounted on each wing tip. It proved overly complex and unreliable for
3300-437: The centre section between the wings are greater. Because it is more compact, the tandem-wing structure is stiffer overall, meaning that less allowance needs to be made for bending, and a smaller safety margin in stress levels is possible, allowing yet further weight and cost reduction. The tandem wing configuration predates successful manned flight. As far back as the fifteenth century, Tito Livio Burraitni experimented with
3375-499: The conventional high-aspect-ratio entries, it proved more controllable and manoeuvrable. This enabled the pilot M. Maneyrol to remain in updraughts for longer than the others. Although Peyret continued to develop the design, in both gliders and powered types, they remained a curiosity. The SFCA continued the work of Peyret after he died, adopting his control system. Their Taupin first flew in 1933. Its design proved practical and some 52 examples were produced. Meanwhile Henri Mignet
3450-509: The craft out of the water during takeoff run, to facilitate lower liftoff speeds. Used by the Russian Rostislav Alexeyev for his ekranoplan. The wings are significantly shorter than those of comparable aircraft, and this configuration requires a high aft-placed horizontal tail to maintain stability. The pitch and altitude stability comes from the lift slope difference between a front low wing in ground-effect (commonly
3525-409: The development of appropriate design and structural configuration, automatic control and navigation systems have been developed. These include altimeters with high accuracy for low altitude flight and lesser dependence on weather conditions. "Phase radio altimeters " have become the choice for such applications beating laser altimeter , isotropic or ultrasonic altimeters . With Russian consultation,
3600-695: The eight-seat Volga-2 in 1985, and Technologies and Transport is developing a smaller version called the Amphistar. Beriev proposed a large craft of the type, the Be-2500, as a "flying ship" cargo carrier, but nothing came of the project. In Germany, Lippisch was asked to build a very fast boat for American businessman Arthur A. Collins . In 1963 Lippisch developed the X-112 , a revolutionary design with reversed delta wing and T-tail. This design proved to be stable and efficient in ground effect, and even though it
3675-415: The first known examples of what would later become called elevons . On 5 October Blériot began taxying trials at Issy-les-Moulineaux . The aircraft was difficult to control on the ground, and the tests ended when the undercarriage collapsed. Bleriot addressed this issue by redesigning the undercarriage, coming up with the arrangement that was used on nearly all of his subsequent aircraft designs. Each wheel
3750-426: The flying species have relatively stiff wings. Due to their small size, they generate lift via clap and fling flapping rather than the usual leading-edge vortex generation of most insects. Many flying beetles, such as the ladybird , have forward wing cases which open out in flight but do not flap significantly. While on the ground they protect the delicate main, hind wings, while in the air they may be used to modify
3825-574: The fore wing converted into a conventional biplane. But it was not until the next year that his type VI , a wheeled tandem monoplane of broadly similar configuration to Langley's Aerodrome, became the first tandem-wing aeroplane to fly. Between 1907 and 1911, the aerodynamics studies of Gustave Eiffel showed that the tandem layout was inherently less aerodynamically efficient that the more conventional. Overlapping with Eiffel's work, Stefan Driezewicki developed and wind-tunnel tested an inherently stable tandem-wing design. He then built and successfully flew
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#17327901692753900-497: The fossil record, principally in China. Both fore and hind limbs were covered in flight feathers and it is thought to have been capable of true flapping flight as well as gliding. Its flight mode is not known. Ground-effect vehicle A ground-effect vehicle ( GEV ), also called a wing-in-ground-effect (WIGE or WIG ), ground-effect craft , wingship , flarecraft or ekranoplan ( Russian : экранопла́н – "screenglider" ),
3975-422: The front wing sweeps back and/or the rear wing sweeps forwards such that they join at or near the tips to form a continuous surface in a hollow diamond or triangle shape. The joined wing is also an example of a closed wing . The Ligeti Stratos is a rare example to have flown. In a conventional layout, the moment arm of the outer section's lifting load is large, and this stresses the root section. However, in
4050-565: The fuselage high enough for a propeller. The high-mounted rear wing had compensating dihedral. The Quickie first flew in 1977 and the next year won the EAA's Outstanding New Design Award at Oshkosh. It became popular, and several variants subsequently appeared. Rutan set up Scaled Composites and some of the company's later designs were also tandems. Several orders of flying insects employ tandem wings, each with its characteristic anatomy and flight modes. Insects with tandem flapping wings include
4125-470: The main wing) and an aft, higher-located second wing nearly out of ground-effect (generally named a stabilizer). Developed by Alexander Lippisch , this wing allows stable flight in ground-effect through self-stabilization. This is the main Class B form of GEV. Tandem wings can have three configurations: Given similar hull size and power, and depending on its specific design, the lower lift-induced drag of
4200-455: The much larger wing on a transport aircraft, though it can do this only when close to the earth's surface. Once sufficient speed has built up, some GEVs may be capable of leaving ground effect and functioning as normal aircraft until they approach their destination. The distinguishing characteristic is that they are unable to land or take off without a significant amount of help from the ground effect cushion, and cannot climb until they have reached
4275-402: The particular wing. This is the primary reason gliders have long wings. Placing the same wing near a surface such as the water or the ground has the same effect as increasing the aspect ratio because the ground prevents wingtip vortices from expanding, but without having the complications associated with a long and slender wing, so that the short stubs on a GEV can produce just as much lift as
4350-619: The past there have been tandem-wing flying reptiles. A tandem wing configuration has two main wing planes, with one located forward and the other to the rear. The difference is greater than the wing chord, so there is a clear gap between them and the aircraft centre of gravity (CG) lies between the wings. Compared to the conventional layout, where the tailplane exerts little or no vertical force in cruising flight, both tandem wings contribute substantially to lift. The basic tandem configuration uses wings which are equal in size and in line with each other. Examples have flown successfully, such as
4425-420: The project ended before it could be modified. The next breakthrough to manufacture came once again in the homebuilt market. Up-and-coming maverick designer Burt Rutan was working on a low-powered but highly efficient plane for home construction. The tandem layout offered a low-drag fixed undercarriage installation, by placing the main wheels in housings at the tips of the fore wing and applying anhedral to raise
4500-420: The rear wing, reducing the angle of attack (AoA) of the rear. At high aircraft AoA, this causes the front wing to stall first, allowing safer flight at low speeds than the equivalent conventional layout. It also offers good STOL performance. Tandem wings have also been used on ground-effect vehicles , where the front wing is used to direct air downwards beneath the rear wing to create a lifting air cushion. In
4575-460: The same time as the Taupin, it became a craze, hundreds were built and variations developed in many countries. However stability issues relating to the variable front wing could lead to lethal crashes in the hands of the novice pilot, and the type eventually fell out of favour. During the late 1930s, Maurice Delanne was working on tandem-wing designs. He proposed a fighter, the Delanne 10, featuring
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#17327901692754650-421: The subject. The French author Maurice Le Sueur had added a suggestion based on this phenomenon: "Here the imagination of inventors is offered a vast field. The ground interference reduces the power required for level flight in large proportions, so here is a means of rapid and at the same time economic locomotion: Design an airplane which is always within the ground-interference zone. At first glance this apparatus
4725-501: The support of Minister of Defence Dmitriy Ustinov . It produced the most successful ekranoplan so far, the 125-tonne A-90 Orlyonok . These craft were originally developed as high-speed military transports and were usually based on the shores of the Caspian Sea and Black Sea . The Soviet Navy ordered 120 Orlyonok -class ekranoplans , but this figure was later reduced to fewer than 30 vessels, with planned deployment mainly in
4800-464: The technology of the day. Other tandem approaches such as the Delanne were largely forgotten, until David Lockspeiser conceived of his Land Development Aircraft, a low-cost utility transport. It was to utilise three interchangeable wing component; one each mounted high up for the left and right rear wings, and a third fore wing mounted centrally beneath the nose. His prototype LDA-01 flew in 1971. It proved successful enough to develop for production, but
4875-407: The underside, while decreasing pressure across the top. The high and low pressures are maintained until they flow off the ends of the wings, where they form vortices which in turn are the major cause of lift-induced drag —normally a significant portion of the drag affecting an aircraft. The greater the span of a wing, the less induced drag created for each unit of lift and the greater the efficiency of
4950-738: The vehicle in an emergency. Since most GEVs are designed to operate from water, accidents and engine failure typically are less hazardous than in a land-based aircraft, but the lack of altitude control leaves the pilot with fewer options for avoiding collision, and to some extent that negates such benefits. Low altitude brings high-speed craft into conflict with ships, buildings and rising land, which may not be sufficiently visible in poor conditions to avoid. GEVs may be unable to climb over or turn sharply enough to avoid collisions, while drastic, low-level maneuvers risk contact with solid or water hazards beneath. Aircraft can climb over most obstacles, but GEVs are more limited. In high winds, take-off must be into
5025-422: The wind, which takes the craft across successive lines of waves, causing heavy pounding, stressing the craft and creating an uncomfortable ride. In light winds, waves may be in any direction, which can make control difficult as each wave causes the vehicle to both pitch and roll. The lighter construction of GEVs makes their ability to operate in higher sea states less than that of conventional ships, but greater than
5100-423: The wing to assist the takeoff; however they differ from hovercraft in still requiring forward motion to generate sufficient lift to fly. Although the GEV may look similar to the seaplane and share many technical characteristics, it is generally not designed to fly out of ground effect. It differs from the hovercraft in lacking low-speed hover capability in much the same way that a fixed-wing airplane differs from
5175-460: The wing was moved from its position immediately above the lower longerons to a position about two thirds of the way up the fuselage, and a tubular steel cabane structure was added to take the wing's bracing wires. In this configuration the aircraft was flown by Blériot on 6 December. On this occasion he succeeded in making a U-turn in the air, and the performance of the aircraft was impressive enough for Patrick Alexander to write "I think Blériot
5250-577: Was developed during his consultancy period in South Africa. It was a simple and low-cost design of a first 4-seater tandem-airfoil flairboat completely constructed of aluminium. The prototype was in the SAAF Port Elizabeth Museum from 4 July 2007 until 2013, and is now in private use. Pictures of the museum show the boat after some years outside the museum and without protection against the sun. The consultancy of Günther Jörg,
5325-425: Was mounted on a castering trailing arm which was free to slide up and down along the round cross-section vertical members of a fixed, four-sided "bedstead" frame, the movement being sprung by bungee cords . The aircraft was first flown on 16 November, when Blériot made a flight of around 500 m (1,600 ft), and further flights were made during November. At the end of November further modifications were made:
5400-550: Was registered as a ship in the Singapore Registry of Ships. The University of Duisburg-Essen is supporting an ongoing research project to develop the Hoverwing . German engineer Günther Jörg, who had worked on Alexeyev's first designs and was familiar with the challenges of GEV design, developed a GEV with two wings in a tandem arrangement, the Jörg-II. It was the third, manned, tandem-airfoil boat, named "Skimmerfoil", which
5475-611: Was successfully tested, Collins decided to stop the project and sold the patents to the German company Rhein Flugzeugbau (RFB), which further developed the inverse delta concept into the X-113 and the six-seat X-114 . These craft could be flown out of ground effect so that, for example, peninsulas could be overflown. Hanno Fischer took over the works from RFB and created his own company, Fischer Flugmechanik, which eventually completed two models. The Airfisch 3 carried two persons, and
5550-404: Was taking a very different approach to flight control. Intended for amateurs to build at home, his Pou-du-Ciel (flying flea) had a novel two-axis control system to make it easy to fly. No ailerons were needed because when the rudder was operated, yaw-roll coupling ensured that the plane banked into a turn. For pitch control the whole front wing tilted to act as a canard elevator. Introduced at much
5625-479: Was the French-built Peyret tandem glider , which won the first British gliding competition in 1922. Peyret's novel control system comprised full-span trailing edge surfaces on all four wings. These operated in pairs on each side as ailerons, in pairs fore and aft as elevators, and synchronously as flaps for low-speed flight. The system proved effective and, despite the glider being less efficient than
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