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66-407: The Be-6 was a gull-winged aircraft with twin oval vertical stabilizers on top of a deep fuselage . The aircraft was of all-metal construction except for fabric covering the rudders and ailerons. The engines were installed in the bends of the wings, with the floats on an underwing cantilever rack. Each float was divided into four watertight compartments. The Be-6 was built from 1949 to 1957 at

132-413: A turn and slip indicator are used when there is zero visibility. Increasingly, anti-collision warning systems such as FLARM are also used and are even mandatory in some European countries. An Emergency Position-Indicating Radio Beacon ( ELT ) may also be fitted into the glider to reduce search and rescue time in case of an accident. Much more than in other types of aviation, glider pilots depend on

198-423: A variometer and an airband radio ( transceiver ), each of which may be required in some countries. A transponder may be installed to assist controllers when the glider is crossing busy or controlled airspace. This may be supplemented by ADS-B . Without these devices access to some airspace may become increasingly restricted in some countries. In countries where cloud-flying is allowed, an artificial horizon or

264-472: A 220 km (140 mi) flight between the Wasserkuppe and Magdeburg in late August 1930 that established a new world record, quickly encouraged numerous aircraft designers to perform their own investigations into the gull wing. Accordingly, numerous other gliders, as well as other platforms, would soon feature broadly similar wing configurations as well. Having become a trend of the glider industry during

330-573: A consequence of the rapid aeronautical advances made during the late 1930s, the P.11 was outclassed by newer fighters such as the Messerschmitt Bf 109 at the onset of the conflict. Examples: During the 1930s, a derivative of the standard design, known as the inverted gull wing , was developed. It was chiefly used on single engine military aircraft with increasingly powerful engines. Before contra-rotating propellers came into use, such powers required larger diameter propellers but clearance between

396-501: A day if the weather is suitable. Early gliders had no cockpit and the pilot sat on a small seat located just ahead of the wing. These were known as " primary gliders " and they were usually launched from the tops of hills, though they are also capable of short hops across the ground while being towed behind a vehicle. To enable gliders to soar more effectively than primary gliders, the designs minimized drag. Gliders now have very smooth, narrow fuselages and very long, narrow wings with

462-406: A flight and even, in some cases, for take-off . Some high-performance motor gliders (known as "self-sustaining" gliders) may have an engine-driven retractable propeller which can be used to sustain flight. Other motor gliders have enough thrust to launch themselves before the engine is retracted and are known as "self-launching" gliders. Another type is the self-launching "touring motor glider", where

528-418: A glider's contest ID when flying in close proximity to one another to alert them of potential dangers. For example, during gatherings of multiple gliders within thermals (known as "gaggles"), one pilot might report "Six-Seven-Romeo I am right below you". Fibreglass gliders are invariably painted white to minimise their skin temperature in sunlight. Fibreglass resin loses strength as its temperature rises into

594-423: A height of 300 metres (1,000 ft). Glide slope control devices are then used to adjust the height to assure landing at the desired point. The ideal landing pattern positions the glider on final approach so that a deployment of 30–60% of the spoilers/dive brakes/flaps brings it to the desired touchdown point. In this way the pilot has the option of opening or closing the spoilers/air-brakes to extend or steepen

660-433: A high aspect ratio and winglets . The early gliders were made mainly of wood with metal fastenings, stays and control cables. Later fuselages made of fabric-covered steel tube were married to wood and fabric wings for lightness and strength. New materials such as carbon-fiber , fiber glass and Kevlar have since been used with computer-aided design to increase performance. The first glider to use glass-fiber extensively

726-470: A high wing arrangement, because such wing could be thinnest by the fuselage, and in theory should limit pilot's view no more than A-pillars of a windscreen in a car body. Gliders were the first aircraft to feature the gull wing, starting with the Weltensegler in 1921; it was not until the record-breaking Fafnir at the end of that decade did the configuration gain popularity. Beyond becoming popular for

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792-701: A higher speed at any given glide angle. This is an advantage in strong conditions when the gliders spend only a small amount of time climbing in thermals. The pilot can jettison the water ballast before it becomes a disadvantage in weaker thermal conditions. Another use of water ballast is to dampen air turbulence such as might be encountered during ridge soaring . To avoid undue stress on the airframe, gliders must jettison any water ballast before landing. Most gliders are built in Europe and are designed to EASA Certification Specification CS-22 (previously Joint Aviation Requirements -22). These define minimum standards for safety in

858-660: A large degree due to post-World War I regulations forbidding the construction and flight of motorised planes in Germany, so the country's aircraft enthusiasts often turned to gliders and were actively encouraged by the German government, particularly at flying sites suited to gliding flight like the Wasserkuppe . The sporting use of gliders rapidly evolved in the 1930s and is now their main application. As their performance improved, gliders began to be used for cross-country flying and now regularly fly hundreds or even thousands of kilometres in

924-532: A major innovation of the PZL P.1 was its relatively high-mounted gull wing. Seeking to protect his new wing arrangement, Puławski filed for an associated patent for this wing arrangement during the following year. The arrangement devised by Puławski has been referred to as the "Puławski Wing" or the "Polish Wing". The PZL P.1 led to a production model, the PZL P.7 , of which 149 were produced between 1932 and 1933. The gull wing

990-508: A minimum loss of height in between. Sailplanes have rigid wings and either skids or undercarriage . In contrast hang gliders and paragliders use the pilot's feet for the start of the launch and for the landing. These latter types are described in separate articles, though their differences from sailplanes are covered below. Sailplanes are usually launched by winch or aerotow, though other methods, auto tow and bungee, are occasionally used. These days almost all gliders are sailplanes, but in

1056-445: A separate control. Although there is only a single main wheel, the glider's wing can be kept level by using the flight controls until it is almost stationary. Pilots usually land back at the airfield from which they took off, but a landing is possible in any flat field about 250 metres long. Ideally, should circumstances permit, a glider would fly a standard pattern , or circuit , in preparation for landing, typically starting at

1122-676: A significant distance forward for a small decrease in altitude. In North America the term 'sailplane' is also used to describe this type of aircraft. In other parts of the English-speaking world, the word 'glider' is more common. Gliders benefit from producing very low drag for any given amount of lift, and this is best achieved with long, thin wings , a slender fuselage and smooth surfaces with an absence of protuberances. Aircraft with these features are able to soar – climb efficiently in rising air produced by thermals or hills. In still air, sailplanes can glide long distances at high speed with

1188-437: A whole decade. During 1930, Alexander Lippisch 's record-breaking Fafnir represented a high-profile comeback for the gull wing, which contributed to its resurgence shortly thereafter. Fafnir featured a laterally stabilising dihedral , an uncommon feature for gliders of the era, which spanned roughly 40 percent of the inner wing span. Lippisch had chosen to adopt this configuration for its increased wingtip clearance, as well as

1254-456: A wide range of characteristics such as controllability and strength. For example, gliders must have design features to minimize the possibility of incorrect assembly (gliders are often stowed in disassembled configuration, with at least the wings being detached). Automatic connection of the controls during rigging is the common method of achieving this. The two most common methods of launching sailplanes are by aerotow and by winch. When aerotowed,

1320-457: Is an aircraft wing configuration with a prominent bend in the wing inner section towards the wing root . Its name is derived from the seabirds which it resembles and from the Polish aircraft designer Zygmunt Puławski who started using this design in his planes. Numerous aircraft have incorporated such wings for a diverse range of purposes. The gull wing was commonly used to improve visibility in

1386-417: Is known as "soaring". By finding lift sufficiently often, experienced pilots fly cross-country , often on pre-declared tasks of hundreds of kilometers, usually back to the original launch site. Cross-country flying and aerobatics are the two forms of competitive gliding . For information about the forces in gliding flight, see lift-to-drag ratio . Pilots need some form of control over the glide slope to land

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1452-468: Is sometimes confusion about gliders/sailplanes, hang gliders and paragliders. In particular, paragliders and hang gliders are both foot-launched. The main differences between the types are: Eight competition classes of glider have been defined by the FAI . They are: A large proportion of gliders have been and are still made in Germany, the birthplace of the sport. In Germany there are several manufacturers but

1518-445: Is sufficient wind blowing up the hill. Bungee launching was the predominant method of launching early gliders. Some modern gliders can self-launch by using retractable engines or just retractable propellers. (see motor glider ). These engines can use internal combustion or battery power. Once launched, gliders try to gain height using thermals , ridge lift , lee waves or convergence zones and can remain airborne for hours. This

1584-447: The variometer article for more information). Variometers are sometimes fitted with mechanical or electronic devices to indicate the optimal speed to fly for given conditions. The MacCready setting can be input electronically or adjusted using a ring surrounding the dial. These devices are based on the mathematical theory attributed to Paul MacCready though it was first described by Wolfgang Späte in 1938. MacCready theory solves

1650-510: The Junkers Ju 87 Stuka , a German ground attack aircraft used during the Second World War , is probably its inverted gull wing configuration. The gull wing was first implemented on a glider , specifically the Weltensegler , which performed its maiden flight in 1921. Its wings, which were externally braced, featured swept-back wingtips with negative incidence relative to the remainder of

1716-726: The People's Republic of China PLANAF proved useful in patrolling the long coastline and huge territorial waters off China's coast. During the 1970s the original Shvetsov radial engines began to wear out with no replacements available, so several aircraft were re-engined with WoJiang WJ-6 turboprop engines, in new nacelles, for a new lease of life and were redesignated Qing-6 . Data from The Osprey Encyclopedia of Russian Aircraft from 1875–1995 General characteristics Performance Armament Aircraft of comparable role, configuration, and era Gull wing The gull wing, also known as Polish wing or Puławski wing ,

1782-487: The Short Knuckleduster , Dornier Do 26 , and PBM Mariner , also adopted the gull wing configuration, primarily as it enabled the engines to be positioned higher above the water. A variant of the standard configuration, the inverted gull wing , has been used on numerous fighters to facilitate the use of shorter landing gear and to provide sufficient ground clearance for their propellers. The most distinctive feature of

1848-501: The Space Shuttle with a glide ratio of 4.5:1. High aerodynamic efficiency is essential to achieve a good gliding performance, and so gliders often have aerodynamic features seldom found in other aircraft. The wings of a modern racing glider are designed by computers to create a low-drag laminar flow airfoil . After the wings' surfaces have been shaped by a mould to great accuracy, they are then highly polished. Vertical winglets at

1914-440: The variometer , which is a very sensitive vertical speed indicator , to measure the climb or sink rate of the plane. This enables the pilot to detect minute changes caused when the glider enters rising or sinking air masses. Most often electronic 'varios' are fitted to a glider, though mechanical varios are often installed as back-up. The electronic variometers produce a modulated sound of varying amplitude and frequency depending on

1980-413: The 1930s, the gull wing remained a staple feature amongst high-performance sailplanes through to the 1950s. The gull wing design found its way into seaplanes by the early 1930s. As engine power increased, so did the need for large propellers that could effectively convert power to thrust. The gull wing allowed designers to ensure adequate propeller tip clearance over the water by placing the engines on

2046-471: The 1950s and the subsequent demise of the seaplane prevented widespread use of the gull wing, although it was still used in some post-war designs, like Beriev Be-12 Chaika (the name means 'gull' in Russian). Examples: During the late 1920s, the gull wing design found its way into landplanes. In 1928, the Polish aircraft designer Zygmunt Puławski developed the PZL P.1 , an experimental fighter aircraft ;

Beriev Be-6 - Misplaced Pages Continue

2112-714: The Beriev plant in Taganrog . The aircraft had 19 variants through its production cycle, and 123 aircraft were eventually built. Since requirements of Soviet naval aircraft did not change rapidly, the reliable Be-6 remained in service until the late 1960s. Some aircraft ended service as civilian unarmed transports in Arctic regions. One survivor is preserved at the Ukraine State Aviation Museum in Kyiv , Ukraine . Beriev Be-6s operated by

2178-425: The control stick, thus creating friction between the skid and the ground. The wing tips also have small skids or wheels to protect the wing tips from ground contact. In most high performance gliders the undercarriage can be raised to reduce drag in flight and lowered for landing. Wheel brakes are provided to allow stopping once on the ground. These may be engaged by fully extending the spoilers/air-brakes or by using

2244-439: The descent to reach the touchdown point. This gives the pilot wide safety margins should unexpected events occur. If such control devices are not sufficient, the pilot may utilize maneuvers such as a forward slip to further steepen the glider slope. Most gliders require assistance to launch, though some have an engine powerful enough to launch unaided. In addition, a high proportion of new gliders have an engine which will sustain

2310-401: The ends of the wings decrease drag and so improve wing efficiency. Special aerodynamic seals are used at the ailerons , rudder and elevator to prevent the flow of air through control surface gaps. Turbulator devices in the form of a zig-zag tape or multiple blow holes positioned in a span-wise line along the wing are used to trip laminar flow air into turbulent flow at a desired location on

2376-433: The era in addition to its high-mounted gull wing, has been described as being the most advanced fighter aircraft of its kind in the world upon its introduction. The PZL P.11 served as Poland's primary fighter aircraft during the mid to late 1930s, while its further development, the PZL P.24 , served in the air forces of several countries and was a major success of the Polish aircraft industry. Various flying boats , such as

2442-512: The era in addition to the high-mounted gull wing, such as its all-metal structure and its metal exterior; according to aviation author Jerzy Cynk, the P.11 was commonly considered to have been the most advanced fighter aircraft of its kind in the world upon its introduction. The P.11 served as Poland's primary fighter aircraft during the mid to late 1930s, participating in the Polish campaign of 1939 to resist an invasion by neighbouring Nazi Germany . As

2508-545: The glass-fiber Libelle of the 1960s increased that to 36:1, and modern flapped 18 meter gliders such as the ASG29 have a glide ratio of over 50:1. The largest open-class glider, the Eta , has a span of 30.9 meters and has a glide ratio over 70:1. Compare this to the Gimli Glider , a Boeing 767 which ran out of fuel mid-flight and was found to have a glide ratio of 12:1, or to

2574-678: The glider in the air, but is insufficiently powerful to launch the glider. Compared with self-launchers these lower powered engines have advantages in weight, lower costs and pilot licensing. The engines can be electric, jet, or two-stroke gasoline. Gliders in continental Europe use metric units, like km/h for airspeed and m/s for lift and sink rate . In the United States, United Kingdom, Australia and some other countries gliders use knots and ft / min in common with commercial aviation worldwide. In addition to an altimeter , compass , and an airspeed indicator , gliders are often equipped with

2640-409: The glider to Earth in a short distance. Early glider designs used skids for landing, but modern types generally land on wheels. Some of the earliest gliders used a dolly with wheels for taking off and the dolly was jettisoned as the glider left the ground, leaving just the skid for landing. A glider may be designed so the center of gravity (CG) is behind the main wheel so the glider sits nose high on

2706-427: The glider. In powered aircraft, this is done by reducing engine thrust. In gliders, other methods are used to either reduce the lift generated by the wing, increase the drag of the entire glider, or both. Glide slope is the distance traveled for each unit of height lost. In a steady wings-level glide with no wind, glide slope is the same as the lift/drag ratio (L/D) of the glider, called "L-over-D". Reducing lift from

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2772-521: The ground. Other designs may have the CG forward of the main wheel so the nose rests on a nose-wheel or skid when stopped. Skids are now mainly used only on training gliders such as the Schweizer SGS 2–33 . Skids are around 100 millimetres (4 in) wide by 900 mm (3 ft) long and run from the nose to the main wheel. Skids help with braking after landing by allowing the pilot to put forward pressure on

2838-561: The highest point of the wing. The alternative was placing the engine on a pylon. The first flying boat to utilize the gull wing configuration may have been the Short Knuckleduster , which first flew in 1933. The Dornier Do 26 , a high-speed airliner and transport platform, of which six aircraft were built, made its first flight during 1938. The configuration was also used on the US Navy 's PBM Mariner and P5M Marlin maritime patrol aircraft . The emergence of long range, land-based jets in

2904-409: The ill-founded belief that it would improve its stability during turns; however, studies have shown that normal gull wing configurations result in significantly less severe and more easily recoverable stalls. Inverted gull wings exhibit the opposite stall behaviour, but both normal and inverted gull wings impede lift-to-drag ratio and climb performance. The performance demonstrated by Fafnir, such as

2970-456: The improvements in aerodynamics , the performance of gliders has increased. One measure of performance is the glide ratio . A ratio of 30:1 means that in smooth air a glider can travel forward 30 meters while losing only 1 meter of altitude. Comparing some typical gliders that might be found in the fleet of a gliding club – the Grunau Baby from the 1930s had a glide ratio of just 17:1,

3036-472: The main-plane. The Weltensegler also used a unique control system, consisting of a various pulleys and springs connected to a single control stick for the pilot, which warped the wing-tips as directed by the pilot. This unorthodox method relied upon the incidence changing with the increase and release of tension, and was also expected to confer increased stability in pitch and roll by automatic changes in wing-tip incidence; however, it gave no direct control over

3102-507: The mainwheels atop the lower gear strut ends) , the latter factor improving internal wing space. The anhedral of the wing's center-section also permitted the wing and fuselage to meet at the optimum angle for minimizing drag , without using wing root fairings or other measures. Another reason for having an inverted gull wing is to permit clearance for a large external bomb load, as on the Junkers Ju 87 Stuka . The inverted gull wing has been described by aviation author Manfred Griehl as being

3168-449: The most distinctive feature of the Ju 87. These wings, which comprised conventional Junkers double-wing construction, reportedly gave the Ju 87 a considerable advantage over its contemporaries during take-off; relatively large lift forces were created through the aerofoil even when flown at a shallow angle, reducing take-off and landing runs. They also provided a high level of ground visibility to

3234-454: The next three decades amongst high-performance gliders, various ground-based aircraft and flying boats also adopted various forms of gull wings. It rose to particular prominence in Poland, where the Polish aviation designer Zygmunt Puławski developed a range of fighter aircraft during the late 1920s and early 1930s; in particular, the PZL P.11 , which possessed various cutting-edge features for

3300-526: The past many gliders were not. These types did not soar . They were simply engine-less aircraft towed by another aircraft to a desired destination and then cast off for landing. The prime example of non-soaring gliders were military gliders (such as those used in the Second World War). They were often used just once and then usually abandoned after landing, having served their purpose. Motor gliders are gliders with engines which can be used for extending

3366-561: The pilot can switch the engine on and off in flight without retracting the propeller. Sir George Cayley 's gliders achieved brief wing-borne hops from around 1849. In the 1890s, Otto Lilienthal built gliders using weight shift for control. In the early 1900s, the Wright Brothers built gliders using movable surfaces for control. In 1903, they successfully added an engine. After World War I gliders were first built for sporting purposes in Germany. Germany's strong links to gliding were to

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3432-417: The pilot, as well as enabling the use of a shorter undercarriage. Examples: Glider (sailplane) A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplanes are aerodynamically streamlined and so can fly

3498-413: The problem of how fast a pilot should cruise between thermals, given both the average lift the pilot expects in the next thermal climb, as well as the amount of lift or sink encountered in cruise mode. Electronic variometers make the same calculations automatically, after allowing for factors such as the glider's theoretical performance , water ballast, headwinds/tailwinds and insects on the leading edges of

3564-491: The propeller tip and ground had to be maintained. Long landing gear legs are heavy, bulky, and weaker than their shorter counterparts. The Vought F4U Corsair , designed from the onset as a carrier-based fighter, not only had the largest propeller of any U.S. fighter, but was also expected to face rough landings aboard a pitching carrier deck. By adopting the inverted gull wing, the landing gear could be shorter and allowed to retract straight back (while twisting through 90º to place

3630-481: The range achievable in direct sun on a hot day. Color is not used except for a few small bright patches on wing tips; these patches (typically orange or red) improving a glider's visibility to other airborne aircraft. Such patches are obligatory for mountain flying in France. Non-fibreglass gliders made of aluminum or wood are not so subject to deterioration at higher temperatures and are often quite brightly painted. There

3696-456: The sailplane is towed behind a powered aircraft using a rope about 60 metres (200 ft) long. The sailplane pilot releases the rope after reaching the desired altitude. However, the rope can be released by the towplane also in case of emergency. Winch launching uses a powerful stationary engine located on the ground at the far end of the launch area. The sailplane is attached to one end of 800 to 1,200 metres (2,600 to 3,900 ft) of cable and

3762-399: The strength of the lift or sink, so that the pilot can concentrate on centering a thermal, watching for other traffic, on navigation, and weather conditions. Rising air is announced to the pilot as a rising tone, with increasing pitch as the lift increases. Conversely, descending air is announced with a lowering tone, which advises the pilot to escape the sink area as soon as possible. (Refer to

3828-685: The underside of a single wing, and also on the fin and rudder . Registration marks are assigned by gliding associations such as the US Soaring Society of America , and are unrelated to national registrations issued by entities such as the US Federal Aviation Administration . This need for visual ID has somewhat been supplanted by GPS position recording. Insignias are useful in two ways: First, they are used in radio communications between gliders, as pilots use their competition number as their call signs . Secondly, to easily tell

3894-423: The water ballast is advantageous if the lift is likely to be strong, and may also be used to adjust the glider's center of mass . Moving the center of mass toward the rear by carrying water in the vertical stabilizer reduces the required down-force from the horizontal stabilizer and the resultant drag from that down-force. Although heavier gliders have a slight disadvantage when climbing in rising air, they achieve

3960-448: The winch rapidly winds it in. The sailplane can gain about 270 to 910 metres (900 to 3,000 ft) of height with a winch launch, depending on the headwind. Less often, automobiles are used to pull sailplanes into the air, either by pulling them directly or through the use of a reverse pulley in a similar manner to the winch launch. Elastic ropes (known as bungees ) are occasionally used at some sites to launch gliders from slopes, if there

4026-456: The wing-tips. The flying career of the Weltensegler was very brief, it being destroyed during the 1921 Rhön gliding competition after the wing failed during a sharp spiralling dive at excessive speed, resulting in the death of Willy Leusch, the Weltensegler's company test pilot. Following the Weltensegler's tragic loss, the gull wing was avoided by the majority of aircraft designers for almost

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4092-400: The wing. This flow control prevents the formation of laminar flow bubbles and ensures the absolute minimum drag. Bug-wipers may be installed to wipe the wings while in flight and remove insects that are disturbing the smooth flow of air over the wing. Modern competition gliders carry jettisonable water ballast (in the wings and sometimes in the vertical stabilizer). The extra weight provided by

4158-462: The wings and/or increasing drag will reduce the L/D allowing the glider to descend at a steeper angle with no increase in airspeed. Simply pointing the nose downwards only converts altitude into a higher airspeed with a minimal initial reduction in total energy. Gliders, because of their long low wings, create a high ground effect which can significantly increase the glide angle and make it difficult to bring

4224-640: The wings. Soaring flight computers running specialized soaring software, have been designed for use in gliders. Using GPS technology in conjunction with a barometric device these tools can: After the flight the GPS data may be replayed on computer software for analysis and to follow the trace of one or more gliders against a backdrop of a map, an aerial photograph or the airspace. So that ground-based observers may identify gliders in flight or in gliding competition , registration marks ("insignias" or "competition numbers" or "contest ID") are displayed in large characters on

4290-534: Was the Akaflieg Stuttgart FS-24 Phönix which first flew in 1957. This material is still used because of its high strength to weight ratio and its ability to give a smooth exterior finish to reduce drag. Drag has also been minimized by more aerodynamic shapes and retractable undercarriages. Flaps are fitted to the trailing edges of the wings on some gliders to optimise lift and drag at a wide range of speeds. With each generation of materials and with

4356-458: Was used to improve visibility in a high wing arrangement, because such wing could be thinnest by the fuselage, and in theory should limit pilot's view no more than A-pillars of a windscreen in a car body. It was used on multiple fighter aircraft, including the PZL P.11 and Soviet Polikarpov I-15 . The PZL P.11 was a further improvement of the PZL P.7 that was in production throughout the early 1930s. It possessed various cutting-edge features for

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