An aircraft is a machine, able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, airships and hot air balloons; the human activity that surrounds aircraft is called aviation. The science of aviation, including designing and building aircraft, is called aeronautics. 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 lift type, aircraft propulsion and others. Flying model craft and stories of manned flight go back many centuries, however the first manned ascent – and safe descent – in modern times took place by larger hot-air balloons developed in the 18th century; each of the two World Wars led to great technical advances. The history of aircraft can be divided into five eras: Pioneers of flight, from the earliest experiments to 1914.
First World War, 1914 to 1918. Aviation between the World Wars, 1918 to 1939. Second World War, 1939 to 1945. Postwar era called the jet age, 1945 to the present day. Aerostats use buoyancy to float in the air in much the same way, they are characterized by one or more large gasbags or canopies, filled with a low-density gas such as helium, hydrogen, or hot air, less dense than the surrounding air. When the weight of this is added to the weight of the aircraft structure, it adds up to the same weight as the air that the craft displaces. Small hot-air balloons called sky lanterns were first invented in ancient China prior to the 3rd century BC and used in cultural celebrations, were only the second type of aircraft to fly, the first being kites which were first invented in ancient China over two thousand years ago. A balloon was any aerostat, while the term airship was used for large, powered aircraft designs – fixed-wing. In 1919 Frederick Handley Page was reported as referring to "ships of the air," with smaller passenger types as "Air yachts."
In the 1930s, large intercontinental flying boats were 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, of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by a rigid outer framework and separate aerodynamic skin surrounding the gas bags, were produced, the Zeppelins being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so "airship" came to be synonymous with these aircraft. Several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a "balloon" is an unpowered 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, 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. These soon became known as blimps. During the Second World War, this shape was adopted for tethered balloons; the nickname blimp was adopted along with the shape. In modern times, any small dirigible or airship is called a blimp, though a blimp may be unpowered as well as powered. Heavier-than-air aircraft, such as airplanes, must find some way to push air or gas downwards, so that a reaction occurs to push the aircraft upwards; this dynamic movement through the air is the origin of the term aerodyne. There are two ways to produce dynamic upthrust: aerodynamic lift, powered lift in the form of engine thrust. Aerodynamic lift involving wings is the most common, with fixed-wing aircraft being kept in the air by the forward movement of wings, rotorcraft by spinning wing-shaped rotors sometimes called rotary wings. A wing is a flat, horizontal surface shaped in cross-section as an aerofoil. To fly, air must generate lift.
A flexible wing is a wing made of fabric or thin sheet material stretched over a rigid frame. A kite is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed, or rotary. With powered lift, the aircraft directs its engine thrust vertically downward. V/STOL aircraft, such as the Harrier Jump Jet and F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight. A pure rocket is not regarded as an aerodyne, because it does not depend on the air for its lift. Rocket-powered missiles that obtain aerodynamic lift at high speed due to airflow over their bodies are a marginal case; the forerunner of the fixed-wing aircraft is the kite. Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the wind blowing over its wings to provide lift. Kites were the first kind of aircraft to fly, were invented in China around 500 BC.
Much aerodynamic research was done with kites before test aircraft, wind tunnels, computer modelling programs became available. The first heavier-than-air craft capable of controlled free-flight were gliders. A glider designed by Geo
Japan Airlines Flight 123
Japan Airlines Flight 123 was a scheduled domestic Japan Airlines passenger flight from Tokyo's Haneda Airport to Osaka International Airport, Japan. On August 12, 1985, a Boeing 747SR operating this route suffered a sudden decompression twelve minutes into the flight and crashed in the area of Mount Takamagahara, Gunma Prefecture, 100 kilometres from Tokyo thirty-two minutes later; the crash site was near Mount Osutaka. Japan's Aircraft Accident Investigation Commission concluded that the rapid decompression was caused by a faulty repair by Boeing technicians after a tailstrike incident during a landing at Osaka Airport seven years earlier. A doubler plate on the rear bulkhead of the plane had been improperly repaired, compromising the plane's airworthiness. Cabin pressurization continued to expand and contract the improperly repaired bulkhead until the day of the accident, when the faulty repair failed, causing the rapid decompression that ripped off a large portion of the tail and caused the loss of hydraulic controls to the entire plane.
The aircraft, configured with increased economy class seating, was carrying 524 people. Casualties of the crash included 505 of the 509 passengers; some passengers survived the initial crash but subsequently died of their injuries hours mostly due to the Japan Self-Defense Forces's decision to wait until the next day to go to the crash site, after declining an offer from a nearby United States Air Force base to start an immediate rescue operation. It remains the deadliest single-aircraft accident in aviation history; the accident aircraft was registered JA8119 and was a Boeing 747-146SR. Its first flight was on January 28, 1974, it had more than 18,800 cycles. At the time of the accident the aircraft was on the fifth of its six planned flights of the day. There were fifteen crew members, including 12 flight attendants; the cockpit crew consisted of the following: Captain Masami Takahama from Akita, served as a training instructor for First Officer Yutaka Sasaki on the flight, supervising him while handling the radio communications.
A veteran pilot, having logged 12,400 total flight hours 4,850 of which were accumulated flying 747s, Masami Takahama was aged 49 at the time of the accident. First Officer Yutaka Sasaki from Kobe was in line for promotion to the rank of Captain and flew Flight 123 as one of his training flights. Sasaki, 39 years old at the time of the incident, had 4,000 total flight hours to his credit and he had logged 2,650 hours in the 747. Flight Engineer Hiroshi Fukuda from Kyoto, the 46-year-old veteran flight engineer of the flight who had 9,800 total flight hours, of which 3,850 were accrued flying 747s; the flight was around the Obon holiday period in Japan, when many Japanese people make yearly trips to their hometowns or resorts. Around twenty-one non-Japanese boarded the flight. By August 13, 1985, Geoffrey Tudor, a spokesman for Japan Airlines, stated that the list included four residents of Hong Kong, two each from Italy and the United States, one each from West Germany and the United Kingdom.
Some foreigners had dual nationalities, some of them were residents of Japan. The four survivors, all female, were seated on the left side and toward the middle of seat rows 54–60, in the rear of the aircraft; the four survivors were: Yumi Ochiai, a 26-year-old off-duty JAL flight attendant, jammed between seats. Air Disaster Volume 2 stated. Kawakami's parents and younger sister died in the crash, she was the last survivor to be released from the hospital, she was treated at the Matsue Red Cross Hospital in Matsue, Shimane Prefecture before her release on Friday, November 22, 1985. Among the dead was singer Kyu Sakamoto, famous for the hit song known in the United States under the title "Sukiyaki." The aircraft landed at Haneda from New Chitose Airport at 4:50PM as JL514. After more than an hour on the ramp, Flight 123 pushed back from gate 18 at 6:04 p.m. and took off from Runway 15L at Haneda Airport in Ōta, Japan, at 6:12 p.m. twelve minutes behind schedule. About 12 minutes after takeoff, at near cruising altitude over Sagami Bay, the aircraft's aft pressure bulkhead burst open due to a pre-existing defect stemming from a panel, incorrectly repaired after a tailstrike accident 7 years earlier.
This caused a rapid decompression of the aircraft, bringing down the ceiling around the rear lavatories, damaging the unpressurized fuselage aft of the bulkhead, unseating the vertical stabilizer, severing all four hydraulic lines. A photograph taken from the ground confirmed; the pilots set their transponder to broadcast a distress signal. Afterwards, Captain Takahama contacted Tokyo Area Control Center to declare an emergency, to request to return to Haneda Airport and following emergency landing vectors to Oshima. Tokyo Control approved a right-hand turn to a heading of 90° east back towards Oshima, however the plane did not follow the directions and continued to fly a westerly course, it was at this point that the pilots became aware that the aircraft had become uncontrollable, the Flight Enginee
An aileron is a hinged flight control surface forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll, which results in a change in flight path due to the tilting of the lift vector. Movement around this axis is called'rolling' or'banking'; the modern aileron was invented and patented by the British scientist Matthew Piers Watt Boulton in 1868, based on his 1864 paper On Aërial Locomotion. Though there was extensive prior art in the 19th century for the aileron and its functional analog, wing warping, in 1906 the United States granted an expansive patent to the Wright Brothers of Dayton, for the invention of a system of aerodynamic control that manipulated an airplane's control surfaces. Considerable litigation ensued within the United States over the legal issues of lateral roll control, until the First World War compelled the U. S. Government to legislate a legal resolution; the name "aileron", from French, meaning "little wing" refers to the extremities of a bird's wings used to control their flight.
It first appeared in print in the 7th edition of Cassell's French-English Dictionary of 1877, with its lead meaning of "small wing". In the context of powered airplanes it appears in print about 1908. Prior to that, ailerons were referred to as rudders, their older technical sibling, with no distinction between their orientations and functions, or more descriptively as horizontal rudders. Among the earliest printed aeronautical use of'aileron' was that in the French aviation journal L'Aérophile of 1908. Ailerons had more or less supplanted other forms of lateral control, such as wing warping, by about 1915, well after the function of the rudder and elevator flight controls had been standardised. Although there were many conflicting claims over who first invented the aileron and its function, i.e. lateral or roll control, the flight control device was invented and described by the British scientist and metaphysicist Matthew Piers Watt Boulton in his 1864 paper On Aërial Locomotion. He was the first to patent an aileron control system in 1868.
Boulton's description of his lateral flight control system was both complete. It was "the first record we have of appreciation of the necessity for active lateral control as distinguished from.... With this invention of Boulton's we have the birth of the present-day three torque method of airborne control" as was praised by Charles Manly; this was endorsed by C. H. Gibbs-Smith. Boulton's British patent, No. 392 of 1868, issued about 35 years before ailerons were "reinvented" in France, became forgotten and lost from sight until after the flight control device was in general use. Gibbs-Smith stated on several occasions that if the Boulton patent had been revealed at the time of the Wright brothers' legal filings, they might not have been able to claim priority of invention for the lateral control of flying machines; the fact that the Wright brothers were able to gain a patent in 1906 did not invalidate Boulton's lost and forgotten invention. Boulton had described and patented ailerons in 1868 and they were not used on manned aircraft until they were employed on Robert Esnault-Pelterie’s glider in 1904, although in 1871 a French military engineer, Charles Renard and flew an unmanned glider incorporating ailerons on each side, activated by a Boulton-style pendulum controlled single-axis autopilot device.
The pioneering U. S. aeronautical engineer Octave Chanute published descriptions and drawings of the Wright brothers' 1902 glider in the leading aviation periodical of the day, L'Aérophile, in 1903. This prompted Esnault-Pelterie, a French military engineer, to build a Wright-style glider in 1904 that used ailerons in lieu of wing warping; the French journal L’Aérophile published photos of the ailerons on Esnault-Pelterie’s glider which were included in his June 1905 article, its ailerons were copied afterward. The Wright brothers used wing warping instead of ailerons for roll control on their glider in 1902, about 1904 their Flyer II was the only aircraft of its time able to do a coordinated banked turn. During the early years of powered flight the Wrights had better roll control on their designs than airplanes that used movable surfaces. From 1908, as aileron designs were refined it became clear that ailerons were much more effective and practical than wing warping. Ailerons had the advantage of not weakening the airplane's wing structure as did the wing warping technique, one reason for Esnault-Pelterie's decision to switch to ailerons.
By 1911 most biplanes used ailerons rather than wing warping—by 1915 ailerons had become universal on monoplanes as well. The U. S. Government, frustrated by the lack of its country's aeronautical advances in the years leading up to World War I, enforced a patent pool putting an end to the Wright brothers patent war; the Wright company changed its aircraft flight controls from wing warping to the use of ailerons at that time as well. Others who were thought to have been the first to introduce ailerons included: American John J. Montgomery included spring-loaded trailing edge flaps on his second glider: these were operable by the pilot as ailerons. In 1886 his third glider design used rotation of the entire wing rather than just a trailing edge portion for roll control. By his own accounts all of these changes in addition to his use of an elevator for pitch control provided "entire control of the machine in the wind, preventing it from upsetting." New Zealander Richard Pearse reputedly made a power
The mechanical structure of an aircraft is known as the airframe. This structure is considered to include the fuselage and wings, exclude the propulsion system. Airframe design is a field of aerospace engineering that combines aerodynamics, materials technology and manufacturing methods with a focus on performance, as well as reliability and cost. Modern airframe history began in the United States when a 1903 wood biplane made by Orville and Wilbur Wright showed the potential of fixed-wing designs. In 1912 the Deperdussin Monocoque pioneered the light 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. Well known aircraft from that era include the Dutch designer Anthony Fokker's combat aircraft for the German Empire's Luftstreitkräfte, U. S. Curtiss flying boats and the German/Austrian Taube monoplanes; these used hybrid metal structures. By the 1915/16 timeframe, the German Luft-Fahrzeug-Gesellschaft firm had devised a monocoque all-wood structure with only a skeletal internal frame, using strips of plywood laboriously "wrapped" in a diagonal fashion in up to four layers, around concrete male molds in "left" and "right" halves, known as Wickelrumpf construction - this first appeared on the 1916 LFG Roland C.
II, would be licensed to Pfalz Flugzeugwerke for its D-series biplane fighters. In 1916 the German Albatros D. III biplane fighters featured semi-monocoque fuselages with load-bearing plywood skin panels glued to longitudinal longerons and bulkheads. Similar methods to the Albatros firm's concept were used by both Hannoversche Waggonfabrik for their light two-seat CL. II through CL. V designs, by Siemens-Schuckert for their Siemens-Schuckert D. III and higher-performance D. IV biplane fighter designs; the Albatros D. III construction was of much less complexity than the patented LFG Wickelrumpf concept for their outer skinning. German engineer Hugo Junkers first flew all-metal airframes in 1915 with the all-metal, cantilever-wing, stressed-skin monoplane Junkers J 1 made of steel, it developed further with lighter weight duralumin, invented by Alfred Wilm in Germany before the war. I of 1918, whose techniques were adopted unchanged after the war by both American engineer William Bushnell Stout and Soviet aerospace engineer Andrei Tupolev, proving to be useful for aircraft up to 60 meters in wingspan by the 1930s.
The J 1 of 1915, the D. I fighter of 1918, were followed in 1919 by the first all-metal transport aircraft, the Junkers F.13 made of Duralumin as the D. I had been. 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; the Hall XFH naval fighter prototype flown in 1929 was the first aircraft with a riveted metal fuselage: an aluminum skin over steel tubing, Hall pioneered flush rivets and butt joints between skin panels in the Hall PH flying boat flying in 1929. Based on the Italian Savoia-Marchetti S.56, the 1931 Budd BB-1 Pioneer experimental flying boat was constructed of corrosion-resistant stainless steel assembled with newly developed spot welding by U. S. railcar maker Budd Company. The original Junkers corrugated duralumin-covered airframe philosophy culminated in the 1932-origin Junkers Ju 52 trimotor airliner, used throughout World War II by the Nazi German Luftwaffe for transport and paratroop needs.
Andrei Tupolev's designs in Joseph Stalin's Soviet Union designed a series of all-metal aircraft of increasing size culminating in the largest aircraft of its era, the eight-engined Tupolev ANT-20 in 1934, Donald Douglas' firm's developed the iconic Douglas DC-3 twin-engined airliner in 1936. They were among the most successful designs to emerge from the era through the use of all-metal airframes. In 1937, the Lockheed XC-35 was the first aircraft constructed with cabin pressurization to underwent extensive high-altitude flight tests, paving the way for the first pressurised transport aircraft, the Boeing 307 Stratoliner. During World War II, military needs again dominated airframe designs. Among the best known were the US C-47 Skytrain, B-17 Flying Fortress, B-25 Mitchell and P-38 Lightning, British Vickers Wellington that used a geodesic construction method, Avro Lancaster, all revamps of original designs from the 1930s; the first jets were not made in large quantity. Due to wartime scarcity of aluminum, the de Havilland Mosquito fighter-bomber was built from wood—plywood facings bonded to a balsawood core and formed using molds to produce monocoque structures, leading to the development of metal-to-metal bonding used for the de Havilland Comet and Fokker F27 and F28.
Postwar commercial airframe design focused on airliners, on turboprop engines, on Jet engines: turbojets and turbofans. The higher speeds and tensile stresses of turboprops and jets were major challenges. Newly developed aluminum alloys with copper and zinc were critical to these designs. Flown in 1952 and designed to cruise at Mach 2 where skin friction required its heat resistance, the Douglas X-3 Stiletto was the first titanium aircraft but it was underpowered and supersonic.
The National Aeronautics and Space Administration is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research. NASA was established in 1958; the new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science. Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, the Space Shuttle. NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the Space Launch System and Commercial Crew vehicles; the agency is responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA science is focused on better understanding Earth through the Earth Observing System. From 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1.
In the early 1950s, there was challenge to launch an artificial satellite for the International Geophysical Year. An effort for this was the American Project Vanguard. After the Soviet launch of the world's first artificial satellite on October 4, 1957, the attention of the United States turned toward its own fledgling space efforts; the US Congress, alarmed by the perceived threat to national security and technological leadership, urged immediate and swift action. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever. On January 14, 1958, NACA Director Hugh Dryden published "A National Research Program for Space Technology" stating: It is of great urgency and importance to our country both from consideration of our prestige as a nation as well as military necessity that this challenge be met by an energetic program of research and development for the conquest of space... It is accordingly proposed that the scientific research be the responsibility of a national civilian agency...
NACA is capable, by rapid extension and expansion of its effort, of providing leadership in space technology. While this new federal agency would conduct all non-military space activity, the Advanced Research Projects Agency was created in February 1958 to develop space technology for military application. On July 29, 1958, Eisenhower signed the National Aeronautics and Space Act, establishing NASA; when it began operations on October 1, 1958, NASA absorbed the 43-year-old NACA intact. A NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA. A significant contributor to NASA's entry into the Space Race with the Soviet Union was the technology from the German rocket program led by Wernher von Braun, now working for the Army Ballistic Missile Agency, which in turn incorporated the technology of American scientist Robert Goddard's earlier works. Earlier research efforts within the US Air Force and many of ARPA's early space programs were transferred to NASA.
In December 1958, NASA gained control of the Jet Propulsion Laboratory, a contractor facility operated by the California Institute of Technology. The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee is associated with the President's political party, a new administrator is chosen when the Presidency changes parties; the only exceptions to this have been: Democrat Thomas O. Paine, acting administrator under Democrat Lyndon B. Johnson, stayed on while Republican Richard Nixon tried but failed to get one of his own choices to accept the job. Paine was confirmed by the Senate in March 1969 and served through September 1970. Republican James C. Fletcher, appointed by Nixon and confirmed in April 1971, stayed through May 1977 into the term of Democrat Jimmy Carter. Daniel Goldin was appointed by Republican George H. W. Bush and stayed through the entire administration of Democrat Bill Clinton.
Robert M. Lightfoot, Jr. associate administrator under Democrat Barack Obama, was kept on as acting administrator by Republican Donald Trump until Trump's own choice Jim Bridenstine, was confirmed in April 2018. Though the agency is independent, the survival or discontinuation of projects can depend directly on the will of the President; the first administrator was Dr. T. Keith Glennan appointed by Republican President Dwight D. Eisenhower. During his term he brought together the disparate projects in American space development research; the second administrator, James E. Webb, appointed by President John F. Kennedy, was a Democrat who first publicly served under President Harry S. Truman. In order to implement the Apollo program to achieve Kennedy's Moon la
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 reduce form drag and interference drag, to improve appearance. On aircraft, fairings are found on: Belly fairing Also called a "ventral fairing", it is located on the underside of the fuselage between the main wings, it can cover additional cargo storage or fuel tanks. Cockpit fairing Also called a "cockpit pod", it protects the crew on ultralight trikes. Made from fiberglass, it may incorporate a windshield. Elevator and horizontal stabilizer tips Elevator and stabilizer tips fairings smooth out airflow at the tips. Engine cowlings Engine cowlings reduce parasitic drag by reducing the surface area, having a smooth surface and thus leading to laminar flow, having a nose cone shape, which prevents early flow separation; 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 tip fairings Fin and rudder tip fairings reduce drag at low angles of attack, but reduce the stall angle, so the fairing of control surface tips depends on the application. Fillets Fillets smooth the airflow at the junction between two components like the fuselage and wing, or the 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 transonic 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, as they enclose the mechanisms for deploying the wing flaps. 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 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 and such friction drag. At the leading and trailing edge it consists of much larger taper and smooths out the pressure differences: High pressure at the leading and trailing edge, low pressure on top of the wing and around the fuselage. Wing tips Wing tips are formed as complex shapes to reduce vortex generation and so drag at low speed. Wheels on fixed gear aircraft Wheel fairings are called "wheel pants", "speed fairings" or, in the United Kingdom, "wheel spats"; these fairings are a trade-off in advantages, as they increase the frontal and surface area, but provide a smooth surface, a faired nose and tail for laminar flow, in an attempt to reduce the turbulence created by the round wheel and its associated gear legs and brakes.
They 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
A rudder is a primary control surface used to steer a ship, submarine, aircraft, or other conveyance that moves through a fluid medium. On an aircraft the rudder is used to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Rudders are shaped so as to minimize hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical aircraft, the rudder is operated by pedals via mechanical hydraulics. A rudder is "part of the steering apparatus of a boat or ship, fastened outside the hull", denoting all different types of oars and rudders.
More the steering gear of ancient vessels can be classified into side-rudders and stern-mounted rudders, depending on their location on the ship. A third term, steering oar, can denote both types. In a Mediterranean context, side-rudders are more called quarter-rudders as the term designates more the place where the rudder was mounted. Stern-mounted rudders are uniformly suspended at the back of the ship in a central position. Although some classify a steering oar as a rudder, others argue that the steering oar used in ancient Egypt and Rome was not a true rudder and define only the stern-mounted rudder used in ancient Han China as a true rudder; the steering oar has the capacity to interfere with handling of the sails while it was fit more for small vessels on narrow, rapid-water transport. In regards to the ancient Phoenician use of the steering oar without a rudder in the Mediterranean, Leo Block writes: A single sail tends to turn a vessel in an upwind or downwind direction, rudder action is required to steer a straight course.
A steering oar was used at this time. With a single sail, a frequent movement of the steering oar was required to steer a straight course; the second sail, located forward, could be trimmed to offset the turning tendency of the main sail and minimize the need for course corrections by the steering oar, which would have improved sail performance. The steering oar or steering board is an oversized oar or board to control the direction of a ship or other watercraft prior to the invention of the rudder, it is attached to the starboard side in larger vessels, though in smaller ones it is if attached. Rowing oars set aside for steering appeared on large Egyptian vessels long before the time of Menes. In the Old Kingdom as many as five steering oars are found on each side of passenger boats; the tiller, at first a small pin run through the stock of the steering oar, can be traced to the fifth dynasty. Both the tiller and the introduction of an upright steering post abaft reduced the usual number of necessary steering oars to one each side.
Single steering oars put on the stern can be found in a number of tomb models of the time during the Middle Kingdom when tomb reliefs suggests them employed in Nile navigation. The first literary reference appears in the works of the Greek historian Herodotus, who had spent several months in Egypt: "They make one rudder, this is thrust through the keel" meaning the crotch at the end of the keel. In Iran, oars mounted on the side of ships for steering are documented from the 3rd millennium BCE in artwork, wooden models, remnants of actual boats. Roman navigation used sexillie quarter steering oars that went in the Mediterranean through a long period of constant refinement and improvement, so that by Roman times ancient vessels reached extraordinary sizes; the strength of the steering oar lay in its combination of effectiveness and simpleness. Roman quarter steering oar mounting systems survived intact through the medieval period. By the first half of the 1st century AD, steering gear mounted on the stern were quite common in Roman river and harbour craft as proved from reliefs and archaeological finds.
A tomb plaque of Hadrianic age shows a harbour tug boat in Ostia with a long stern-mounted oar for better leverage. The boat featured a spritsail, adding to the mobility of the harbour vessel. Further attested Roman uses of stern-mounted steering oars includes barges under tow, transport ships for wine casks, diverse other ship types; the well-known Zwammerdam find, a large river barge at the mouth of the Rhine, featured a large steering gear mounted on the stern. According to new research, the advanced Nemi ships, the palace barges of emperor Caligula, may have featured 14 m long rudders; the world's oldest known depiction of a sternpost-mounted rudder can be seen on a pottery model of a Chinese junk dating from the 1st century AD during the Han Dynasty, predating their appearance in the West by a thousand years. In China, miniature models of ships t