1.
Glass cockpit
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A glass cockpit is an aircraft cockpit that features electronic flight instrument displays, typically large LCD screens, rather than the traditional style of analog dials and gauges. This simplifies aircraft operation and navigation and allows pilots to focus only on the most pertinent information and they are also popular with airline companies as they usually eliminate the need for a flight engineer, saving costs. In recent years the technology has become available in small aircraft. As aircraft displays have modernized, the sensors that feed them have modernized as well, traditional gyroscopic flight instruments have been replaced by electronic attitude and heading reference systems and air data computers, improving reliability and reducing cost and maintenance. GPS receivers are usually integrated into glass cockpits, glass cockpits originated in military aircraft in the late 1960s and early 1970s, an early example is the Mark II avionics of the F-111D, which featured a multi-function display. Prior to the 1970s, air operations were not considered sufficiently demanding to require advanced equipment like electronic flight displays. Also, computer technology was not at a level where sufficiently light, the increasing complexity of transport aircraft, the advent of digital systems and the growing air traffic congestion around airports began to change that. The success of the NASA-led glass cockpit work is reflected in the acceptance of electronic flight displays beginning with the introduction of the MD-80 in 1979. Airlines and their passengers alike have benefited, the safety and efficiency of flights have been increased with improved pilot understanding of the aircrafts situation relative to its environment. By the end of the 1990s, liquid-crystal display panels were increasingly favored among aircraft manufacturers because of their efficiency, earlier LCD panels suffered from poor legibility at some viewing angles and poor response times, making them unsuitable for aviation. The glass cockpit has become standard equipment in airliners, business jets and it was fitted into NASAs Space Shuttle orbiters Atlantis, Columbia, Discovery, and Endeavour, and the current Russian Soyuz TMA model spacecraft that was launched in 2002. By the end of the century glass cockpits began appearing in general aviation aircraft as well, in 2003, Cirrus Designs SR20 and SR22 became the first light aircraft equipped with glass cockpits, which they made standard on all Cirrus aircraft. The Lockheed Martin F-35 Lightning II features a panoramic cockpit display touchscreen that replaces most of the switches and toggles found in an aircraft cockpit and they look and behave very similarly to other computers, with windows and data that can be manipulated with point-and-click devices. They also add terrain, approach charts, weather, vertical displays, the improved concepts enable aircraft makers to customize cockpits to a greater degree than previously. All of the manufacturers involved have chosen to do so in one way or another—such as using a trackball, many of the modifications offered by the aircraft manufacturers improve situational awareness and customize the human-machine interface to increase safety. Modern glass cockpits might include Synthetic Vision or Enhanced Vision systems, Enhanced Vision systems add real-time information from external sensors, such as an infrared camera. All new airliners such as the Airbus A380, Boeing 787 and private jets such as Bombardier Global Express, many modern general aviation aircraft are available with glass cockpits. Systems such as the Garmin G1000 are now available on many new GA aircraft, many small aircraft can also be modified post-production to replace analogue instruments
2.
Flight instruments
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Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with information about the flight situation of that aircraft, such as altitude, airspeed and direction. They improve safety by allowing the pilot to fly the aircraft in level flight, visual flight rules require an airspeed indicator, an altimeter, and a compass or other suitable magnetic direction indicator. Instrument flight rules require a gyroscopic pitch-bank, direction and rate of turn indicator, plus a slip-skid indicator, adjustable altimeter. Flight into Instrument meteorological conditions require radio navigation instruments for precise takeoffs, the term is sometimes used loosely as a synonym for cockpit instruments as a whole, in which context it can include engine instruments, navigational and communication equipment. Many modern aircraft have electronic flight instrument systems, most regulated aircraft have these flight instruments as dictated by the US Code of Federal Regulations, Title 14, Part 91. They are grouped according to system, compass systems. It is adjustable for local barometric pressure which must be set correctly to obtain accurate altitude readings, as the aircraft ascends, the capsules expand and the static pressure drops, causing the altimeter to indicate a higher altitude. The opposite effect occurs when descending, with the advancement in aviation and increased altitude ceiling the altimeter dial had to be altered for use both at higher and lower altitudes. This modification was introduced in the early sixties after the recurrence of air caused by the confusion in the pilots mind. At higher altitudes the window will disappear, the airspeed indicator shows the aircrafts speed relative to the surrounding air. It works by measuring the pressure in the aircrafts Pitot tube relative to the ambient static pressure. The Indicated airspeed must be corrected for pressure and temperature in order to obtain the True airspeed. The instrument is color coded to indicate important airspeeds such as the speed, never-exceed airspeed. The VSI senses changing air pressure, and displays that information to the pilot as a rate of climb or descent in feet per minute, the compass shows the aircrafts heading relative to magnetic north. Errors include Variation, or the difference between magnetic and true direction, and Deviation, caused by the wiring in the aircraft. Additionally, the compass is subject to Dip Errors, while reliable in steady level flight it can give confusing indications when turning, climbing, descending, or accelerating due to the inclination of the Earths magnetic field. For this reason, the indicator is also used for aircraft operation. The attitude indicator shows the relation to the horizon
3.
Variometer
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It can be calibrated in feet per minute, knots or metres per second, depending on country and type of aircraft. In powered flight the pilot makes frequent use of the VSI to ascertain that level flight is being maintained, in gliding, the instrument is used almost continuously during normal flight, often with an audible output, to inform the pilot of rising or sinking air. It is usual for gliders to be equipped with more than one type of variometer, the simpler type does not need an external source of power and can therefore be relied upon to function regardless of whether a battery or power source has been fitted. The electronic type with audio needs a source to be operative during the flight. The instrument is of little interest during launching and landing, with the exception of aerotow, variometers measure the rate of change of altitude by detecting the change in air pressure as altitude changes. A simple variometer can be constructed by adding a large reservoir to augment the capacity of a common aircraft rate-of-climb instrument. In its simplest electronic form, the instrument consists of an air bottle connected to the atmosphere through a sensitive air flow meter. The faster the aircraft is ascending, the faster the air flows, air flowing out of the bottle indicates that the altitude of the aircraft is increasing. Air flowing into the bottle indicates that the aircraft is descending and these designs tend to be smaller as they do not need the air bottle. They are more reliable as there is no bottle to be affected by changes in temperature, the term vertical speed indicator or VSI is most often used for the instrument when it is installed in a powered aircraft. The term variometer is most often used when the instrument is installed in a glider or sailplane, an Inertial-lead or Instantaneous VSI uses accelerometers to provide a quicker response to changes in vertical speed. Human beings, unlike birds and other flying animals, are not able directly to sense climb, before the invention of the variometer, sailplane pilots found it very hard to soar. Although they could readily detect abrupt changes in speed, their senses did not allow them to distinguish lift from sink. The actual climb/sink rate could not even be guessed at, unless there was some clear fixed visual reference nearby, being near a fixed reference means being near to a hillside, or to the ground. Except when hill-soaring, these are generally very unprofitable positions for glider pilots to be in, the most useful forms of lift are found at higher altitudes and it is very hard for a pilot to detect or exploit them without the use of a variometer. After the variometer was invented in 1929 by Alexander Lippisch and Robert Kronfeld, variometers also became important in foot-launch hang gliding, where the open-to-air pilot hears the wind but needs the variometer to help him or her to detect regions of rising or sinking air. In early hang gliding, variometers were not needed for the short flights or flights close to ridge lift, but the variometer became key as pilots began making longer flights. The first portable variometer for use in hang gliders was the Colver Variometer by Colver Soaring Instruments which served to extend the sport into cross-country thermal flying, as the sport of gliding developed, however, it was found that these very simple uncompensated instruments had their limitations
4.
Aircraft
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An aircraft is a machine that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the lift of an airfoil. The human activity that surrounds aircraft is called aviation, crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as type, aircraft propulsion, usage. Each of the two World Wars led to technical advances. Consequently, the history of aircraft can be divided into five eras, Pioneers of flight, first World War,1914 to 1918. Aviation between the World Wars,1918 to 1939, Second World War,1939 to 1945. Postwar era, also called the jet age,1945 to the present day, aerostats use buoyancy to float in the air in much the same way that ships float on the water. They are characterized by one or more large gasbags or canopies, filled with a relatively low-density gas such as helium, hydrogen, or hot air, which is less dense than the surrounding air. When the weight of this is added to the weight of the aircraft structure, a balloon was originally any aerostat, while the term airship was used for large, powered aircraft designs – usually fixed-wing. In 1919 Frederick Handley Page was reported as referring to ships of the air, in the 1930s, large intercontinental flying boats were also sometimes referred to as ships of the air or flying-ships. – though none had yet been built, the advent of powered balloons, called dirigible balloons, and later of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by an outer framework and separate aerodynamic skin surrounding the gas bags, were produced. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, then several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a balloon is an aerostat and an airship is a powered one. A powered, steerable aerostat is called a dirigible, sometimes this term is applied only to non-rigid balloons, and sometimes dirigible balloon is regarded as the definition of an airship. Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back and these soon became known as blimps. During the Second World War, this shape was adopted for tethered balloons, in windy weather
5.
Space Shuttle
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The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U. S. National Aeronautics and Space Administration, as part of the Space Shuttle program. Its official program name was Space Transportation System, taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development, the first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. Five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, the Shuttle fleets total mission time was 1322 days,19 hours,21 minutes and 23 seconds. Shuttle components included the Orbiter Vehicle, a pair of solid rocket boosters. The Shuttle was launched vertically, like a rocket, with the two SRBs operating in parallel with the OVs three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, at the conclusion of the mission, the orbiter fired its OMS to de-orbit and re-enter the atmosphere. The orbiter then glided as a spaceplane to a landing, usually at the Shuttle Landing Facility of KSC or Rogers Dry Lake in Edwards Air Force Base. After landing at Edwards, the orbiter was back to the KSC on the Shuttle Carrier Aircraft. The first orbiter, Enterprise, was built in 1976 for use in Approach, four fully operational orbiters were initially built, Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in accidents, Challenger in 1986 and Columbia in 2003, with a total of fourteen astronauts killed. A fifth operational orbiter, Endeavour, was built in 1991 to replace Challenger, the Space Shuttle was retired from service upon the conclusion of Atlantiss final flight on July 21,2011. Nixons post-Apollo NASA budgeting withdrew support of all components except the Shuttle. The vehicle consisted of a spaceplane for orbit and re-entry, fueled by liquid hydrogen and liquid oxygen tanks. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982, all launched from the Kennedy Space Center, Florida. The system was retired from service in 2011 after 135 missions, the program ended after Atlantis landed at the Kennedy Space Center on July 21,2011. Major missions included launching numerous satellites and interplanetary probes, conducting space science experiments, the first orbiter vehicle, named Enterprise, was built for the initial Approach and Landing Tests phase and lacked engines, heat shielding, and other equipment necessary for orbital flight. A total of five operational orbiters were built, and of these and it was used for orbital space missions by NASA, the US Department of Defense, the European Space Agency, Japan, and Germany. The United States funded Shuttle development and operations except for the Spacelab modules used on D1, sL-J was partially funded by Japan
6.
United States Patent and Trademark Office
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The USPTO is unique among federal agencies because it operates solely on fees collected by its users, and not on taxpayer dollars. The USPTO is based in Alexandria, Virginia, after a 2005 move from the Crystal City area of neighboring Arlington, the head of the USPTO is Michelle K. Lee. She took up her new role on January 13,2014, on March 13, she formally took office as Director after being nominated by President Barack Obama and confirmed by the U. S. Senate. She formerly served as the Director of the USPTOs Silicon Valley satellite office, the USPTO cooperates with the European Patent Office and the Japan Patent Office as one of the Trilateral Patent Offices. The USPTO mission is to maintain a permanent, interdisciplinary historical record of all U. S. patent applications in order to fulfill objectives outlined in the United States Constitution. The legal basis for the United States patent system is Article 1, Section 8, an additional building in Arlington, Virginia, was opened in 2009. The USPTO was expected by 2014 to open its first ever satellite offices in Detroit, Dallas, Denver, the first satellite office opened in Detroit on July 13,2012. In 2013, due to the sequestration, the satellite office for Silicon Valley. However, renovation and infrastructure updates continued after the sequestration, and the Silicon Valley location is due to open in San Jose City Hall in mid-2015. As of September 30,2009, the end of the U. S. governments fiscal year, of those,6,242 were patent examiners and 388 were trademark examining attorneys, the rest are support staff. They are generally newly graduated scientists and engineers, recruited from universities around the nation. They hold degrees in scientific disciplines, but who do not necessarily hold law degrees. Unlike patent examiners, trademark examiners must be licensed attorneys, all examiners work under a strict, count-based production system. For every application, counts are earned by composing, filing, and mailing a first office action on the merits, the Patent Operations of the office is divided into nine different technology centers that deal with various arts. Prior to 2012, decisions of patent examiners may be appealed to the Board of Patent Appeals and Interferences, the United States Supreme Court may ultimately decide on a patent case. Similarly, decisions of trademark examiners may be appealed to the Trademark Trial and Appeal Board, with subsequent appeals directed to the Federal Circuit, under the America Invents Act, the BPAI was converted to the Patent Trial and Appeal Board or PTAB. In recent years, the USPTO has seen increasing delays between when a patent application is filed and when it issues, to address its workload challenges, the USPTO has undertaken an aggressive program of hiring and recruitment. The USPTO hired 1,193 new patent examiners in Fiscal Year 2006,1,215 new examiners in fiscal 2007, in 2006, USPTO instituted a new training program for patent examiners called the Patent Training Academy
7.
Fixed-wing aircraft
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A fixed-wing aircraft is an aircraft, such as an aeroplane, which is capable of flight using wings that generate lift caused by the vehicles forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft, in which the form a rotor mounted on a spinning shaft. Glider fixed-wing aircraft, including free-flying gliders of various kinds and tethered kites, powered fixed-wing aircraft that gain forward thrust from an engine include powered paragliders, powered hang gliders and some ground effect vehicles. The wings of an aircraft are not necessarily rigid, kites, hang-gliders, variable-sweep wing aircraft. Most fixed-wing aircraft are flown by a pilot on board the aircraft, kites were used approximately 2,800 years ago in China, where materials ideal for kite building were readily available. Some authors hold that leaf kites were being flown much earlier in what is now Indonesia, by at least 549 AD paper kites were being flown, as it was recorded in that year a paper kite was used as a message for a rescue mission. Ancient and medieval Chinese sources list other uses of kites for measuring distances, testing the wind, lifting men, signaling, and communication for military operations. Stories of kites were brought to Europe by Marco Polo towards the end of the 13th century, although they were initially regarded as mere curiosities, by the 18th and 19th centuries kites were being used as vehicles for scientific research. This machine may have been suspended for its flight, some of the earliest recorded attempts with gliders were those by the 9th-century poet Abbas Ibn Firnas and the 11th-century monk Eilmer of Malmesbury, both experiments injured their pilots. In 1799, Sir George Cayley set forth the concept of the aeroplane as a fixed-wing flying machine with separate systems for lift, propulsion. Cayley was building and flying models of fixed-wing aircraft as early as 1803, in 1856, Frenchman Jean-Marie Le Bris made the first powered flight, by having his glider LAlbatros artificiel pulled by a horse on a beach. In 1884, the American John J. Montgomery made controlled flights in a glider as a part of a series of gliders built between 1883-1886, other aviators who made similar flights at that time were Otto Lilienthal, Percy Pilcher, and Octave Chanute. In the 1890s, Lawrence Hargrave conducted research on wing structures and his box kite designs were widely adopted. Although he also developed a type of aircraft engine, he did not create. Sir Hiram Maxim built a craft that weighed 3.5 tons, in 1894, his machine was tested with overhead rails to prevent it from rising. The test showed that it had enough lift to take off, the craft was uncontrollable, which Maxim, it is presumed, realized, because he subsequently abandoned work on it. By 1905, the Wright Flyer III was capable of fully controllable, stable flight for substantial periods, the flight was certified by the FAI. This was the first controlled flight, to be officially recognised, the Bleriot VIII design of 1908 was an early aircraft design that had the modern monoplane tractor configuration
8.
Airframe
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The airframe of an aircraft is its mechanical structure. It is typically considered to include fuselage, wings and undercarriage, airframe design is a field of aerospace engineering that combines aerodynamics, materials technology and manufacturing methods to achieve balances of performance, reliability and cost. Modern airframe history began in the United States when a 1903 wood biplane made by Orville, in 1912 the Deperdussin Monocoque pioneered the light, strong and streamlined monocoque fuselage formed of thin plywood layers over a circular frame, achieving 210 km/h. Many early developments were spurred by military needs during World War I and these used hybrid wood and metal structures. In 1916 the German Albatros D. German engineer Hugo Junkers first flew all-metal airframes in 1915 with the all-metal, cantilever-wing, commercial aircraft development during the 1920s and 1930s focused on monoplane designs using Radial engines. Some were produced as single copies or in small quantity such as the Spirit of St. Louis flown across the Atlantic by Charles Lindbergh in 1927, william Stout designed the all-metal Ford Trimotors in 1926. They were among the most successful designs to emerge from the era through the use of all-metal airframes, during World War II, military needs again dominated airframe designs. The first jets were produced during the war but not made in large quantity, postwar commercial airframe design focused on airliners, on turboprop engines, and then on Jet engines, turbojets and later turbofans. The generally higher speeds and tensile stresses of turboprops and jets were major challenges, Airbus and Boeing are the dominant assemblers of large jet airliners while ATR, Bombardier and Embraer lead the regional airliner market, many manufacturers produce airframe components. It has a carbon fiber fuselage, said to replace 1,200 sheets of aluminum and 40,000 rivets. In February 2017, Airbus installed a 3D printing machine for titanium aircraft structural parts using electron beam additive manufacturing from Sciaky, airframe production has become an exacting process. Manufacturers operate under strict quality control and government regulations, departures from established standards become objects of major concern. A landmark in aeronautical design, the worlds first jet airliner, early models suffered from catastrophic airframe metal fatigue, causing a series of widely publicised accidents. The Royal Aircraft Establishment investigation at Farnborough Airport founded the science of aircraft crash reconstruction, after 3000 pressurisation cycles in a specially constructed pressure chamber, airframe failure was found to be due to stress concentration, a consequence of the square shaped windows. The windows had been engineered to be glued and riveted, but had been punch riveted only, unlike drill riveting, the imperfect nature of the hole created by punch riveting may cause the start of fatigue cracks around the rivet. The Lockheed L-188 Electra turboprop, first flown in 1957 became a lesson in controlling oscillation. Its 1959 crash of Braniff Flight 542 showed the difficulties that the airframe industry, the A300 had experienced other structural problems but none of this magnitude. Longeron Former Chord Aircraft fairing Vertical stabilizer
9.
Bracing (aeronautics)
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In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of strut, which act in compression or tension as the need arises, and/or wires, which act only in tension. Another disadvantage of bracing wires is that they require routine checking and adjustment, or rigging, during the early years of aviation, bracing was a universal feature of all forms of aeroplane, including the monoplanes and biplanes which were then equally common. Today, bracing in the form of lift struts is still used for light commercial designs where a high wing. Bracing works by creating a triangulated truss structure which resists bending or twisting, by comparison, an unbraced cantilever structure bends easily unless it carries a lot of heavy reinforcement. Making the structure allows it to be much lighter and stiffer. To reduce weight and air resistance, the structure may be made hollow, for example, a high-wing monoplane may be given a diagonal lifting strut running from the bottom of the fuselage to a position far out towards the wingtip. This increases the depth of the wing root to the height of the fuselage. Typically, the ends of bracing struts are joined to the internal structural components such as a wing spar or a fuselage bulkhead. Bracing may be used to resist all the forces which occur in an airframe, including lift, weight, drag. A strut is a bracing component stiff enough to resist these forces whether they place it under compression or tension, a wire is a bracing component able only to resist tension, going slack under compression, and consequently is nearly always used in conjunction with struts. A square frame made of bars is not rigid but tends to bend at the corners. Bracing it with a diagonal bar would be heavy. A wire would be much lighter but would stop it collapsing only one way, to hold it rigid, two cross-bracing wires are needed. This method of cross-bracing can be clearly on early biplanes. Another way of arranging a rigid structure is to make the cross pieces solid enough to act in compression and this method was once common on monoplanes, where the wing and a central cabane or a pylon form the cross members while wire bracing forms the outer diamond. Most commonly found on biplane and other aircraft, wire bracing was also common on early monoplanes. Unlike struts, bracing wires always act in tension The thickness and profile of a wire affect the drag it causes, wires may be made of multi-stranded cable, a single strand of piano wire, or aerofoil sectioned steel
10.
Aircraft canopy
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An aircraft canopy is the transparent enclosure over the cockpit of some types of aircraft. The function of the canopy is to provide a weatherproof and reasonably quiet environment for the aircrafts occupants, the canopy will be as aerodynamically shaped as possible to minimize aerodynamic drag. Very early aircraft had no canopies at all, the pilots were exposed to the wind and weather, although most flying was done in good weather. Through World War I most aircraft had no canopy, although they often had a windshield to deflect the prop wash. In the 1920s and 1930s, the speed and altitude of airplanes necessitated a fully enclosed cockpit. Early canopies were made of pieces of Flat glass held in position by a frame. The muntins reduced visibility, which was problematic for military aircraft. Also, glass canopies were much heavier than acrylic canopies, which were first introduced shortly before World War II, the acrylic bubble canopy was used on aircraft such as the Supermarine Spitfire and Westland Whirlwind, which gave better all-round visibility and reduced weight. It is still being used today on most fighter aircraft and this ruse was inspired by animals and fishes that have similar markings on the head and tail, so they can confuse other creatures. Pilots remain skeptical of this feature, asserting that if the enemy is close enough to see the marking, on many high-performance military aircraft, the canopy is an integral part of the ejection seat system. The pilot cannot be ejected from the aircraft until the canopy is no longer in the path of the ejection seat, in most ejection seat equipped aircraft, the canopy is blown upwards and rearwards by explosive charges. The relative wind then blows the canopy away from the ejection path, in that situation, the pilot could possibly impact the canopy when ejecting. To overcome that possibility, some aircraft have a cord of plastic explosive zig-zagging across the canopy over the pilots head. In the event of an ejection, the cord is activated first. Then the ejection seat are launched through the shattered canopy, a technician must meet the qualifications of E-6 in rank. Most modern acrylic canopies are vacuum formed, a sheet of acrylic is secured to a female mould, then the entire assembly is heated in an oven until the acrylic is pliable. The air is removed from the mould and the acrylic sheet is drawn into it. The acrylic is then trimmed to the shape and attached to an aluminum or composite frame
11.
Aircraft fabric covering
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Aircraft fabric covering is a term used for both the material used and the process of covering aircraft open structures. II, in its wrapped Wickelrumpf plywood strip and fabric covering. The purposes of the covering of an aircraft are, To provide a light airproof skin for lifting. To provide structural strength to weak structures. To cover other non-lifting parts of an aircraft to reduce drag, to protect the structure from the elements. Pioneering aviators such as George Cayley and Otto Lilienthal used cotton-covered flying surfaces for their glider designs. The Wright brothers also used cotton to cover their Wright Flyer, other early aircraft used a variety of fabrics, silk and linen being commonly used. Some early aircraft, such as A. V, roes first machines, even used paper as a covering material. Until the development of cellulose based dope in 1911 a variety of methods of finishing the fabric were used, the most popular was the use of rubberised fabrics such as those manufactured by the Continental company. Other methods included the use of sago starch, national insignia painted on the fabric were often cut from downed aircraft and used as war trophies. The German aircraft designer Hugo Junkers is considered one of the pioneers of metal aircraft, the highly flammable mixture of fabric, dope and hydrogen gas was a factor in the demise of the Hindenburg airship. Many transports, bombers and trainers still used fabric, although the flammable nitrate dope was replaced with butyrate dope instead, the Mosquito is an example of a fabric-covered plywood aircraft. The Vickers Wellington used fabric over a geodesic airframe which offered good combat damage resistance, an interesting case of ingenuity under wartime adversity was the Colditz Cock glider. This new fabric could be glued to the airframe instead of sewn, grade A cotton would typically last six to seven years when the aircraft was stored outside, whereas Ceconite, which does not rot like cotton, can last over 20 years. Early attempts to use these modern fabrics with butyrate dope proved that the dope did not adhere at all, nitrate dope was resurrected as the initial system of choice instead, although it was supplanted by new materials too. One fabric system, developed by Ray Stits in the USA and this uses three weights of Dacron fabric sold as by the brand name Ceconite, plus fabric glue for attaching to the airframe, fabric preparation sealer resin and paint. This system is not dope and instead uses vinyl-based chemicals, Ceconite 101 is a certified 3.5 oz/yd² fabric while Ceconite 102 is a 3.16 oz/yd² fabric. There is also an uncertified light Ceconite of 1.87 oz/yd² intended for ultralight aircraft and this method requires physical attachment of the fabric to the airframe in the form of rib-stitching, rivets or capstrips, which are then usually covered with fabric tapes. In addition to Poly-Fiber, a number of companies produce covering processes for certified
12.
Aircraft fairing
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An aircraft fairing is a structure whose primary function is to produce a smooth outline and reduce drag. These structures are covers for gaps and spaces between parts of an aircraft to form drag and interference drag, and to improve appearance. On aircraft, fairings are commonly found on, Cockpit fairing Also called a cockpit pod, commonly made from fiberglass, it may also incorporate a windshield. Elevator and horizontal stabilizer tips Elevator and stabilizer tips fairings smooth out airflow at the tips, the inlet and the nozzle in combination lead to an isotropic speed reduction around the cooling fins and due to the speed-squared law to a reduction in cooling drag. Fin and rudder tips fairings reduce drag at low angles of attack, fillets smooth the airflow at the junction between two components like fuselage and wing, or fuselage and fin. Fixed landing gear junctions Landing gear fairings reduce drag at these junctions, flap track fairings Most jet airliners have a cruising speed between Mach 0.8 and 0.85. For aircraft operating in the regime, wave drag can be minimized by having a cross-sectional area which changes smoothly along the length of the aircraft. This is known as the area rule, on subsonic aircraft such as jet airliners, this can be achieved by the addition of smooth pods on the trailing edges of the wings. These pods are known as anti-shock bodies, Küchemann Carrots, or flap track fairings, spinner To cover and streamline the propeller hub. Strut-to-wing and strut-to-fuselage junctions Strut end fairings reduce drag at these junctions, Tail cones Tail cones reduce the form drag of the fuselage, by recovering the pressure behind it. For the design speed they add no friction drag, Wing root Wing roots are often faired to reduce interference drag between the wing and the fuselage. On top and below the wing it consists of small rounded edge to reduce the surface, Wing tips Wing tips are often formed as complex shapes to reduce vortex generation and so also drag, especially at low speed. Wheels on fixed gear aircraft Wheel fairings are often called wheel pants, speed fairings or, in the UK and they also have the important function of preventing mud and stones from being thrown upwards against the wings or fuselage, or into the propeller on a pusher craft. Bicycle fairing Motorcycle fairing Payload fairing
