67-656: The Schweizer Aircraft Corporation was an American manufacturer of sailplanes , agricultural aircraft and helicopters located in Horseheads, New York . It was incorporated in 1939 by three Schweizer brothers (Paul, William, and Ernest), who built their first glider , the SGP 1-1 , in 1930. Previously the oldest privately owned aircraft company in the United States, Schweizer was acquired by Sikorsky Aircraft Corporation of Stratford, Connecticut in 2004, and became
134-413: 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
201-423: 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
268-401: A NACA airfoil. The 1-34 has no wing washout and instead uses a Wortmann FX 61-163 airfoil at the wing root , transitioning to a Wortmann FX 61-126 airfoil at the wing tip . The tip airfoil stalls at a higher angle of attack, ensuring that the wing root stalls first. The one company concession to the changing Standard Class rules was the development of a retractable landing gear version of
335-501: 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
402-595: A diversified aerospace company. Schweizer Aircraft ceased operations in 2012. It was sold to Schweizer RSG in 2018 and production lines were opened in Fort Worth, Texas . The company was producing two helicopter models in 2021. The 300C and 300CBI The company grew out of the Mercury Glider Club which produced the first two Schweizer gliders in the Schweizers' barn. The company was originally called
469-406: 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
536-491: A fuselage structure that is designed to progressively collapse in the event of a collision. In 1972 Schweizer hired David Thurston and production of his Thurston Teal was part of the agreement to work at Schweizer. The company produced three Schweizer TSC-1A1 Teals and nine TSC-1A2 Teal IIs before production was moved to Teal Aircraft in 1976. The development of the Schweizer SGM 2-37 two-place motor glider for
603-418: 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
670-423: 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
737-433: 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
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#1732793664597804-705: 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
871-728: 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
938-508: 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
1005-445: 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
1072-649: 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
1139-456: 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,
1206-417: 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
1273-471: 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
1340-445: 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
1407-447: 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
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#17327936645971474-757: The Hughes 269 for the United States Army , is one of the most widely used training helicopters in the world. In 1986, Schweizer acquired all rights to the helicopter from McDonnell Douglas, who had purchased Hughes Helicopters in 1984. After Schweizer acquired the FAA Type Certificate, the helicopter was known for a short time as the Schweizer-Hughes 300C and then simply, the Schweizer 300C. The basic design remained unchanged over
1541-573: The MQ-8 Fire Scout helicopter UAV . Schweizer participated in development of Sikorsky's X-2 Demonstrator , a prototype aircraft using co-axial rotor blades with a pusher propeller for extra forward thrust. United Technology Corporation (UTC), then parent company of Sikorsky, shut down Schweizer in December 2012. It was sold to a new company, Schweizer RSG , in 2018 and the production lines were restarted in Fort Worth, Texas . The company
1608-543: The Schweizer Metal Aircraft Company . Attorney Bob McDowell indicated to the Schweizers that they should move their manufacturing operation out of their father's barn and relocate to the Elmira, New York area. The Schweizers received the suggestion positively as they needed more space to produce gliders, but they had no money with which to make the move. McDowell convinced Elmira Industries Inc,
1675-508: 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
1742-766: The United States Air Force Academy in 1982 led to a new area of expertise for the company. In the mid-1960s Lockheed had used the Schweizer SGS 2-32 sailplane as the basis for its YO-3 quiet reconnaissance aircraft. Schweizer decided to develop the SGM 2-37 into a similar concept aircraft as the YO-3. The result was the SA 2-37A and B, known as the RG-8A in military use. The RG-8A was later developed by
1809-440: 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
1876-505: The 1-34 has proven to be a popular club aircraft and ideal for the completion of badge flights . If a greater number of 1-34s had been built, Schweizer indicated that it would have become another one-design class, similar to the 1-26. The 1-34 type certificate is currently held by K & L Soaring of Cayuta, New York . K & L Soaring now provides all parts and support for the Schweizer line of sailplanes. At least two 1-34s have been highly modified. Bob Park's 1-34R, registered N17974,
1943-606: The 1-34, designated as the SGS 1-34R. The 1-34 also features in-flight adjustable rudder pedals and a two-way adjustable seat to accommodate pilots of different heights. The 1-34 was flown in Standard Class competitions, but was out-performed by the new fiberglass European gliders, such as the Glasflügel H-201 Standard Libelle . During the protracted development process, Schweizer Aircraft
2010-474: The U.S. Schweizer produced the Grumman G-164 Ag Cat , a single-engine biplane agricultural aircraft originally developed by Grumman in the 1950s. Under the contract with Grumman the airplane was built almost continuously between 1957 and 1981. During this period of time Schweizer built 2,455 of the airplanes. In 1981 Schweizer bought the rights to the design and continued production under
2077-440: The aircraft was started the Standard Class was new and described a very simple aircraft with terminal velocity dive brakes, fixed landing gear and no water ballast. By the time the 1-34 had flown in 1969 the Standard Class rules had changed to allow essentially unrestricted sailplanes with a 15-metre (49.2 feet) wingspan. The SGS 1-34 is of all metal aluminum semi- monocoque construction. All surfaces are aluminum covered, with
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2144-477: The company in February 2009 included the 300C , 300CBi , and 333 . In 2011 and 2012 Sikorsky Aircraft Corporation laid off all the workers and closed the plant. After the sale of the company, helicopter production was restarted in Fort Worth, Texas in 2018. Schweizer is known for its popular line of gliders (sailplanes), the earliest of which (the model SGP 1-1 ) was produced in 1930. Although very few of
2211-731: The company into the twin piston-engined and twin-boom SA 2-38 Condor with the US military designation of RU-38A Twin Condor. This design was further refined into the turboprop -powered RU-38B Twin Condor . The RU-38 was still in production in 2008. It is believed the US Drug Enforcement Administration purchased aircraft designated Shadowhawk from Schweizer. The aircraft had a poor operational history. They may be designated SA 38B. In partnership with Northrop Grumman (formerly Ryan Aeronautical ), Schweizer developed
2278-425: 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
2345-439: 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
2412-620: The early gliders were built, later models gained popularity, such as the SGS 2-8 and 2-12 , which were adopted by the U.S. Army Air Corps for training as the TG-2 and TG-3 , respectively. The Schweizer SGS 1-23 was a world class competition and record setting glider between its first flight in 1948 and the end of its production in 1967. In the 1950s and 1960s the Schweizer Aircraft Corporation designed and manufactured
2479-401: 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
2546-416: The exception of the rudder which is covered in aircraft fabric. The 1-34 has air brakes capable of limiting the terminal velocity in a vertical dive to the maximum safe speed as specified in the original Standard Class rules. Developing and testing these proved expensive and time-consuming and this also extended the aircraft's development time. The 1-34 was the first Schweizer design to depart from using
2613-558: 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
2680-622: 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
2747-409: 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
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2814-427: 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
2881-469: 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
2948-462: 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,
3015-721: The local business development corporation, to provide space for the Schweizers on the second floor of the Elmira Knitting Mill Building in return for stock in the company. This resulted in the Schweizer Metal Aircraft Company becoming the Schweizer Aircraft Corporation, with a sale of shares to Elmira Industries, local businessmen and soaring pilots. Schweizer primarily produced light, piston-engined helicopters for use in utility and flight-training roles. The Schweizer 300CBi , originally designed and manufactured by Hughes aircraft as
3082-508: The name Schweizer Ag Cat . In 1995 Schweizer sold the rights to the Ag Cat to Ag-Cat Corp. of Malden, Texas . In February 2001 the design was sold to Allied Ag-Cat Productions Inc. of Walnut Ridge, Arkansas . Allied Ag-Cat is not producing new aircraft although a related company operates a large fleet of Ag-Cats. The basic airframe incorporates many safety innovations, including a pressurized cockpit to keep pesticides out, air conditioning and
3149-534: 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
3216-568: 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
3283-413: 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
3350-485: 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
3417-456: 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
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#17327936645973484-399: 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
3551-798: The three principal companies are: Germany also has Stemme and Lange Aviation . Elsewhere in the world, there are other manufacturers such as Jonker Sailplanes in South Africa, Sportinė Aviacija in Lithuania, Allstar PZL in Poland, Let Kunovice and HpH in the Czech Republic and AMS Flight in Slovenia. Schweizer SGS 1-34 The Schweizer SGS 1-34 is a United States Standard Class , single-seat, high-wing glider built by Schweizer Aircraft of Elmira, New York . The 1-34
3618-707: 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
3685-506: The very popular SGS 1-26 and SGS 2-33 gliders. In the 1970s the single place SGS 1-34 (and 1-34R retractable gear version) was introduced. They are easy to fly, with simple construction, and are quite rugged and forgiving. Later in the 1970s and 1980s the higher performance t-tail SGS 1-35 and SGS 1-36 Sprite were introduced. A powered light aircraft , the Schweizer SA 1-30 was tested, but did not go into production. The 2-33
3752-423: 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
3819-448: 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
3886-400: 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
3953-465: 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
4020-643: 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
4087-614: The years. Between Hughes and Schweizer, nearly 3,000 copies of the Model 269/300 have been built and flown over the last 50 years. Schweizer continued to develop the Model 300 by adding a turbine and redesigning the body to create the Schweizer 330 , and then further developments led to the development of the Schweizer 333 . An improved version in the series, the Sikorsky S-434 , was released in 2008. Helicopter products offered by
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#17327936645974154-516: Was adopted by the United States Air Force Academy as the TG-4, for use in introductory airmanship training. The Academy used over a dozen such gliders until 2002 when they were replaced by more modern sailplanes. The Royal Canadian Air Cadets continue to operate a fleet of over seventy 2-33As. The popular Schweizer gliders the single-seat SGS 1-26 , the two-seat 2-33 , and the two or three-seat SGS 2-32 can still be found at many gliding clubs across
4221-403: Was aware that the 1-34 would be overtaken by the changes in class rules and also by the performance of the newer European fiberglass sailplanes, but continued development of the SGS 1-34 anyway. The company identified that there was demand from private owners and especially clubs and commercial operations for a simple, rugged single seat glider with greater performance than the 1-26 . In service
4288-420: Was damaged when a hurricane passed through Georgia and resulted in a hangar collapse. The 1-34R was rebuilt with a V-tail and ballast tanks mounted in the wings that hold 230 lbs (105 kg) of water. The aircraft was subsequently registered in the experimental Racing – Exhibition category. A modified SGS 1-34 airframe with tricycle landing gear and powered by a Lycoming TIO-360 piston engine
4355-413: Was designed over a number of years in the mid-1960s and first flew in 1969. By the time the 1-34 was introduced it was no longer competitive in the Standard Class, but has proven very successful as a club aircraft, being a great "step-up" sailplane for post-solo students and accomplished pilots. The 1-34 was designed over several years to spread out the development costs. At the time the design work on
4422-430: Was producing three models in 2021, the 300C , 300CBi , and 333 . 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 a significant distance forward for
4489-547: 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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