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BFW M.20

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The BFW M.20 (also known as the Messerschmitt M.20 after the designer's surname) was a German single-engine, high-wing monoplane ten-seat passenger transport aircraft , developed in the late 1920s and early 1930s. Deutsche Luft Hansa used it throughout the 1930s on a variety of routes.

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65-442: The M 20 was designed by Willy Messerschmitt at Bayerische Flugzeugwerke , primarily for use with Luft Hansa which had ordered two in advance of the first flight. It was a development of the BFW M.18d eight-seater, equipped with a single 375 kW (500 hp) upright inline water-cooled BMW VIa engine. It had a high, cantilever wing based around a robust D-section box formed from

130-413: 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

195-423: 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

260-452: A clear focus on performance, especially by striving for lightweight construction, but also by minimizing parasitic drag from aerodynamic surfaces. His critics accused him of taking this approach too far in some designs. His falling out with Harth had been over designs Harth felt to be dangerously unstable, and the Me 210 displayed instability, too, which could be cured only by enlarging the airframe and

325-674: 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 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

390-418: 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

455-423: 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

520-433: 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

585-701: 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

650-445: 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

715-401: A single dural spar and dural skin, forward to the leading edge . The fuselage was all-metal, with a mostly dural frame, covered with metal sheeting providing rectangular cross-section accommodation, with four square windows each side, for eight passengers. The single-axle main undercarriage was strutted vertically to the wing. The aircraft made its maiden flight on 26 February 1928, but

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780-657: A tailless aircraft safely controllable, defeated this purpose by increasing drag to the original level and above. Messerschmitt was appointed Honorary Professor by the Munich Technical College in 1930, and the Vice-President of the Deutsche Akademie für Luftfahrtforschung (German Academy of Aeronautical Research). The German government also awarded him the title of Wehrwirtschaftsführer (defense industry leader). In 1938, Adolf Hitler bestowed upon Messerschmitt

845-456: 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,

910-714: A world duration record (albeit unofficially) and they went into partnership for a while running a flying school. The same year, the first plane entirely designed by Messerschmitt flew – the S9 glider. In 1923 Messerschmitt graduated from the Munich Institute of Technology . The same year Harth and Messerschmitt had a falling out and went their separate ways, with Messerschmitt founding his own aircraft company at Augsburg . At first, Messerschmitt built sailplanes, but within two years had progressed via motor gliders to small powered aircraft - sports and touring types. These culminated in

975-450: 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 a minimum loss of height in between. Sailplanes have rigid wings and either skids or undercarriage . In contrast hang gliders and paragliders use

1040-417: 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

1105-518: 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

1170-445: 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

1235-447: 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

1300-600: The German National Prize for Art and Science . In 1979, Messerschmitt was inducted into the International Air & Space Hall of Fame at the San Diego Air & Space Museum . 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

1365-709: The Messerschmitt Kabinenroller . Exporting his talents to Francoist Spain , he designed the Hispano HA-200 jet trainer for Hispano Aviación in Spain in 1952 before eventually being allowed to return to aircraft manufacturing in Germany to licence-produce the Fiat G91 and then Lockheed F-104 Starfighter for the West German Luftwaffe. He designed the later Helwan HA-300 , a light supersonic interceptor, for

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1430-581: The Messerschmitt M 17 and Messerschmitt M 18 designs, which Messerschmitt sold to BFW in 1927, when the Bavarian state government encouraged a merger between the two companies. These were followed by the Messerschmitt M20 light transport in 1928, which proved a disaster for BFW and Messerschmitt himself. Two Deutsche Luft Hansa M20s were involved in serious crashes very soon after purchase, and this led

1495-501: 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

1560-510: 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 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

1625-440: 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

1690-654: The Bf 108 into the Bf 109 fighter. In 1936, the Messerschmitt Bf 109 won the RLM's single-seat fighter contest, and became one of the main Luftwaffe aircraft types. Messerschmitt and his factory thus took an important role in the RLM's armament plans. This role expanded even further when the Messerschmitt Bf 110 also won the multi-purpose fighter contest. On 11 July 1938, Messerschmitt was appointed chairman and managing director of BFW and

1755-541: The Egyptian air forces. This was his last aircraft design. Messerschmitt saw his company through mergers first with Bölkow in 1968 and then Hamburger Flugzeugbau in 1969, at which point it became MBB ( Messerschmitt-Bölkow-Blohm , that became part of EADS now named Airbus ) with Messerschmitt as chairman until 1970 when he retired. He died eight years later, on 15 September 1978 in a Munich hospital in undisclosed circumstances. Messerschmitt's designs were characterized by

1820-714: The German army in 1914 and while he was away at war, Messerschmitt continued work on one of Harth's designs, the S5 glider. In 1917, Messerschmitt himself signed up for military service. Following the war, the two were reunited and continued to work together while Messerschmitt commenced study at the Munich Technical College and Harth built aircraft at the Bayerische Flugzeugwerke (BFW – Bavarian Aircraft Works). The S8 glider they designed and built together in 1921 broke

1885-470: 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 a day if the weather is suitable. Early gliders had no cockpit and

1950-685: The German rearmament programs and Messerschmitt's friendship with Hugo Junkers prevented a stagnation of the careers of himself and BFW, which was started again in 1933. Milch still prevented Messerschmitt's takeover of BFW until 1938, hence the designation "Bf" of early Messerschmitt designs. Data from Messerschmitt: an aircraft album, 'Flugzeug-Typenbuch 1936 , Flight 281028 General characteristics Performance Related development Aircraft of comparable role, configuration, and era Willy Messerschmitt Wilhelm Emil "Willy" Messerschmitt ( German pronunciation: [ˈmɛsɐʃmɪt] ; 26 June 1898 – 15 September 1978)

2015-588: The absolute world airspeed record and held the world speed record for propeller-driven aircraft until 1969. Messerschmitt's firm also produced the first jet-powered fighter to enter service – the Messerschmitt Me 262 . He was born in Frankfurt am Main , the son of Baptist Ferdinand Messerschmitt (1858–1916) and his second wife, Anna Maria Schaller (1867–1942). As a young man, Messerschmitt befriended German sailplane pioneer Friedrich Harth . Harth joined

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2080-494: The aerodynamic surfaces, increasing drag and weight. Messerschmitt's design philosophy also is evident in his arguments with Alexander Lippisch , who was designing the tailless Me 163 rocket fighter for production at the Messerschmitt works. While Lippisch maintained that the tailless design had an advantage, in principle, with regard to total drag, Messerschmitt pointed out that the design compromises, which are necessary to make

2145-452: The airline to cancel their order for the type. This caused a serious cashflow problem for the company and led to its bankruptcy in 1931. The M20 crashes also created a powerful enemy for Messerschmitt in the person of Erhard Milch , the head of Luftwaffe, who had lost a close friend in one of the crashes. The ties that Messerschmitt had formed with leading Nazis Rudolf Hess and Hermann Göring (through Theo Croneiss ) saved him from sharing

2210-470: The atmosphere to gain altitude. Sailplanes are aerodynamically streamlined and so can fly 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

2275-445: The company was renamed after him to Messerschmitt AG . This same year, the company began work on what would eventually become the Me 262 , and on the Messerschmitt Me 210 , planned as successor for the Bf 110. The Me 210 turned out to be plagued by massive development problems that were solved only by evolving the type into the Messerschmitt Me 410 . The resulting problems and delays again put

2340-425: 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

2405-439: 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

2470-401: 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

2535-399: The engine is retracted and are known as "self-launching" gliders. Another type is the self-launching "touring motor glider", where 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,

2600-567: The fate of Milch's other great enemy, Hugo Junkers . To stay in business in the face of Milch ensuring that he would get no government contracts, Messerschmitt had signed agreements with Romania for sales of the M35 and a transport plane, the Messerschmitt M 36 . When Milch learned of this, he publicly denounced Messerschmitt as a traitor, and the Gestapo was sent to question him and other BFW officials. Probably due to Croneiss' intervention, no further action

2665-545: 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

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2730-678: 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

2795-409: 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

2860-427: 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

2925-521: 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

2990-456: 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,

3055-410: The only M.20 to survive the war Hans Hackmack, who died in the first flight of the M 20, was a close friend of Erhard Milch , the head of Luft Hansa and the German civil aviation authorities. Milch was upset by the lack of response from Messerschmitt and this led to a lifelong hatred towards him. Milch eventually cancelled all contracts with Messerschmitt and forced BFW into bankruptcy in 1931. However,

3120-428: 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

3185-481: 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 the past many gliders were not. These types did not soar . They were simply engine-less aircraft towed by another aircraft to

3250-413: 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

3315-481: 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

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3380-556: The reputation of both Messerschmitt and his namesake company in jeopardy. Following World War II, Messerschmitt was tried by a denazification court for using slave labor, and in 1948 was convicted of collaborating with the Nazi regime. After two years in prison, he was released and resumed his position as head of his company. Since Germany was forbidden to manufacture aircraft until 1955, he turned his company to manufacturing prefabricated buildings, sewing machines , and small cars – most notably

3445-456: 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

3510-399: 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

3575-685: 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

3640-423: 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

3705-448: 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

3770-510: The wing and a more rounded vertical tail . The Luft Hansa M.20s entered service in 1929 on routes that went from Switzerland via Germany to the Netherlands and from Stuttgart via Marseille to Barcelona . From the mid-1930s, they were operating German internal and holiday routes. Two were still flying such routes in 1942. One former Luft Hansa airframe went to Brazil in 1937, flying with Varig as PP-VAK , until it crashed on 7 March 1948,

3835-400: 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

3900-462: 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

3965-640: 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

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4030-628: Was a German aircraft designer and manufacturer. In 1934, in collaboration with Walter Rethel , he designed the Messerschmitt Bf 109 , which became the most important fighter aircraft in the Luftwaffe as Germany rearmed prior to World War II . It remains the second most-produced warplane in history, with some 34,000 built, behind the Soviet Ilyushin Il-2 . Another Messerschmitt aircraft, first called "Bf 109R", purpose-built for record setting, but later redesignated Messerschmitt Me 209 , broke

4095-415: Was lost when pilot Hans Hackmack bailed out at low altitude and was killed, after the surface stripped from part of the wing. A second M.20 was flown on 3 August 1928, and became the first of two M.20a series to fly with Luft Hansa. Encouraged by their performance, Luft Hansa ordered 12 more, enlarged, M.20b aircraft. These carried ten passengers in a fuselage with five windows each side. It had dihedral on

4160-725: Was taken. The establishment of the Reichsluftfahrtministerium ("Reich Aviation Ministry" – RLM) by the Nazi government in 1933, headed by Milch, led to a resurgence in the German aircraft industry and the resurrection of BFW. Collaborating with Robert Lusser , Messerschmitt designed the flagship product of the relaunched company. This was a low-wing four seater monoplane called the Messerschmitt M37, but better known by its later RLM designation of Bf 108 . The following year, Messerschmitt incorporated many advanced design features of

4225-534: 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

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