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 fixed-wing aircraft is a flying machine, such as an airplane or aeroplane, capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft, ornithopters; the wings of a fixed-wing aircraft are not rigid. Gliding fixed-wing aircraft, including free-flying gliders of various kinds and tethered kites, can use moving air to gain altitude. Powered fixed-wing aircraft that gain forward thrust from an engine include powered paragliders, powered hang gliders and some ground effect vehicles. Most fixed-wing aircraft are flown by a pilot on board the craft, but some are designed to be unmanned and controlled either remotely or autonomously. Kites were used 2,800 years ago in China, where materials ideal for kite building were available; some authors hold that leaf kites were being flown much earlier in what is now Sulawesi, based on their interpretation of cave paintings on Muna Island off Sulawesi.
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 and communication for military operations. Stories of kites were brought to Europe by Marco Polo towards the end of the 13th century, kites were brought back by sailors from Japan and Malaysia in the 16th and 17th centuries. Although they were regarded as mere curiosities, by the 18th and 19th centuries kites were being used as vehicles for scientific research. Around 400 BC in Greece, Archytas was reputed to have designed and built the first artificial, self-propelled flying device, a bird-shaped model propelled by a jet of what was steam, said to have flown some 200 m; this machine may have been suspended for its flight. One of the earliest purported attempts with gliders was by the 11th-century monk Eilmer of Malmesbury, which ended in failure.
A 17th-century account states that the 9th-century poet Abbas Ibn Firnas made a similar attempt, though no earlier sources record this event. In 1799, Sir George Cayley set forth the concept of the modern aeroplane as a fixed-wing flying machine with separate systems for lift and control. Cayley was building and flying models of fixed-wing aircraft as early as 1803, he built a successful passenger-carrying glider in 1853. In 1856, Frenchman Jean-Marie Le Bris made the first powered flight, by having his glider "L'Albatros 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, protégés of Octave Chanute. In the 1890s, Lawrence Hargrave conducted research on wing structures and developed a box kite that lifted the weight of a man, his box kite designs were adopted. Although he developed a type of rotary aircraft engine, he did not create and fly a powered fixed-wing aircraft.
Sir Hiram Maxim built a craft that weighed 3.5 tons, with a 110-foot wingspan, powered by two 360-horsepower steam engines driving two propellers. In 1894, his machine was tested with overhead rails to prevent it from rising; the test showed. The craft was uncontrollable, which Maxim, it is presumed, because he subsequently abandoned work on it; the Wright brothers' flights in 1903 with their Flyer I are recognized by the Fédération Aéronautique Internationale, the standard setting and record-keeping body for aeronautics, as "the first sustained and controlled heavier-than-air powered flight". By 1905, the Wright Flyer III was capable of controllable, stable flight for substantial periods. In 1906, Brazilian inventor Alberto Santos Dumont designed and piloted an aircraft that set the first world record recognized by the Aéro-Club de France by flying the 14 bis 220 metres in less than 22 seconds; the flight was certified by the FAI. This was the first controlled flight, to be recognised, by a plane able to take off under its own power alone without any auxiliary machine such as a catapult.
The Bleriot VIII design of 1908 was an early aircraft design that had the modern monoplane tractor configuration. It had movable tail surfaces controlling both yaw and pitch, a form of roll control supplied either by wing warping or by ailerons and controlled by its pilot with a joystick and rudder bar, it was an important predecessor of his Bleriot XI Channel-crossing aircraft of the summer of 1909. World War I served as a testbed for the use of the aircraft as a weapon. Aircraft demonstrated their potential as mobile observation platforms proved themselves to be machines of war capable of causing casualties to the enemy; the earliest known aerial victory with a synchronised machine gun-armed fighter aircraft occurred in 1915, by German Luftstreitkräfte Leutnant Kurt Wintgens. Fighter aces appeared. Following WWI, aircraft technology continued to develop. Alcock and Brown crossed the Atlantic non-stop for the first time in 1919; the first commercial flights took place between the United States and Canada in 1919.
The so-called Golden Age of Aviation occurred between the two World War
Aircraft fabric covering
Aircraft fabric covering is a term used for both the material used and the process of covering aircraft open structures. It is used for reinforcing closed plywood structures, the de Havilland Mosquito being an example of this technique, on the pioneering all-wood monocoque fuselages of certain World War I German aircraft like the LFG Roland C. II, in its wrapped Wickelrumpf plywood strip and fabric covering. Early aircraft used organic materials such as cotton and cellulose nitrate dope, modern fabric-covered designs use synthetic materials such as Dacron and butyrate dope for adhesive, this method is used in the restoration of older types that were covered using traditional methods; the purposes of the fabric covering of an aircraft are: To provide a light airproof skin for lifting and control surfaces. To provide structural strength to otherwise weak structures. To cover other non-lifting parts of an aircraft to reduce drag, sometimes forming a fairing. To protect the structure from the elements.
Pioneering aviators such as George Cayley and Otto Lilienthal used cotton-covered flying surfaces for their manned glider designs. The Wright brothers used cotton to cover their Wright Flyer. Other early aircraft used a variety of fabrics and linen being used; some early aircraft, such as A. V. Roe's first machines 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; the advent of cellulose dopes such as "Emaillite" was a major step forward in the production of practical aircraft, producing a surface that remained taut The air battles of World War I were fought with fabric-covered biplanes that were vulnerable to fire due to the flammable properties of the cloth covering and nitrocellulose dope. National insignia painted on the fabric were 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 flammable mixture of fabric and hydrogen gas was a factor in the demise of the Hindenburg airship. By the World War II era many aircraft designs were using metal monocoque structures due to their higher operating airspeeds, although fabric-covered control surfaces were still used on early mark Spitfires and other types; the Hawker Hurricane had a fabric covered fuselage, they had fabric covered wings until 1939. Many transports and trainers still used fabric, although the flammable nitrate dope was replaced with butyrate dope instead, which burns less readily; 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 homebuilt aircraft, intended as a means of escape, employed prison bedding as its covering material.
With the development of modern synthetic materials following World War II, cotton fabrics were replaced in civil aircraft applications by polyethylene terephthalate, known by the trade-name Dacron or Ceconite. This new fabric could be glued to the airframe instead of sewn and heat-shrunk to fit. Grade A cotton would 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 and peeled off in sheets. 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 FAA-approved in 1965, is marketed under the brand name Poly-Fiber; 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 instead uses vinyl-based chemicals.
Ceconite 101 is a certified 3.5 oz/yd ² fabric. There is an uncertified light Ceconite of 1.87 oz/yd² intended for ultralight aircraft. This method requires physical attachment of the fabric to the airframe in the form of rib-stitching, rivets or capstrips, which are usually covered with fabric tapes. In addition to Poly-Fiber, a number of other companies produce covering processes for certified and homebuilt aircraft. Randolph Products and Certified Coatings Products both make butyrate and nitrate-based dopes for use with Dacron fabric. Superflite and Air-Tech systems use a similar fabric, but the finishes are polyurethane-based products with flex agents added; these finishes produce high gloss results. Falconar Avia of Edmonton, Canada developed the Hipec system in 1964 for use with Dacron fabric, it uses a special Hipec Sun Barrier that adheres fabric directly to the aircraft structure in one step, eliminating the need for the riveting, rib-stitching and taping used in traditional fabric processes.
The final paint is applied over the sun barrier to complete the process. Newer systems were developed and distributed by Stewart Systems of Cashmere and Blue River; these two systems use the same certified dacron materials as other systems, but do not use high volatile organic compounds, using water as a carrier i
A former is an object, such as a template, gauge or cutting die, used to form something such as a boat's hull. A former gives shape to a structure that may have complex curvature. A former may become an integral part of the finished structure, as in an aircraft fuselage, or it may be disposable, being using in the construction process and discarded. Here, a former is a structural member of an aircraft fuselage, of which a typical fuselage has a series from the nose to the empennage perpendicular to the longitudinal axis of the aircraft; the primary purpose of formers is to establish the shape of the fuselage and reduce the column length of stringers to prevent instability. Formers are attached to longerons, which support the skin of the aircraft; the "former-and-longeron" technique was adopted from boat construction, was typical of light aircraft built until the advent of structural skins, such as fiberglass and other composite materials. Many of today's light aircraft, homebuilt aircraft in particular, are still designed in this way.
A former may instead be a temporary shape over which a structure is built, the former subsequently being discarded in whole or part, as follows: Strip-built boat construction uses formers over which thin plank strips are applied and glued. in some cases, some of the formers may be incorporated as structural ribs. In civil engineering, bridge building, architecture, arches may be built upon a wooden former, removed once the keystone is securely in place
In aeronautics, a spoiler is a device intended to intentionally reduce the lift component of an airfoil in a controlled way. Most spoilers are plates on the top surface of a wing that can be extended upward into the airflow to spoil it. By so doing, the spoiler creates a controlled stall over the portion of the wing behind it reducing the lift of that wing section. Spoilers differ from airbrakes in that airbrakes are designed to increase drag without affecting lift, while spoilers reduce lift as well as increasing drag. Spoilers fall into two categories: those that are deployed at controlled angles during flight to increase descent rate or control roll, those that are deployed on landing to reduce lift and increase drag. In modern fly-by-wire aircraft, the same set of control surfaces serve both functions. Spoilers are used by nearly every glider to control their rate of descent and thus achieve a controlled landing. An increased rate of descent can be achieved by lowering the nose of an aircraft, but this would result in increased speed.
Spoilers enable the approach to be made at a safe speed for landing. Airliners are always fitted with spoilers. Spoilers are used to increase descent rate without increasing speed, their use is limited, however, as the turbulent airflow that develops behind them causes noise and vibration, which may cause discomfort to passengers. Spoilers may be differentially operated for roll control instead of ailerons. On landing, the spoilers are nearly always deployed to help slow the aircraft; the increase in form drag created by the spoilers directly assists the braking effect. However, the real gain comes as the spoilers cause a dramatic loss of lift and hence the weight of the aircraft is transferred from the wings to the undercarriage, allowing the wheels to be mechanically braked with less tendency to skid. In air-cooled piston engine aircraft, spoilers may be needed to avoid shock cooling the engines. In a descent without spoilers, air speed is increased and the engine will be at low power, producing less heat than normal.
The engine may cool too resulting in stuck valves, cracked cylinders or other problems. Spoilers alleviate the situation by allowing the aircraft to descend at a desired rate while letting the engine run at a power setting that keeps it from cooling too quickly. Spoiler controls can be used for descent control; some aircraft use spoilers in combination with or in lieu of ailerons for roll control to reduce adverse yaw when rudder input is limited by higher speeds. For such spoilers the term spoileron has been coined. In the case of a spoileron, in order for it to be used as a control surface, it is raised on one wing only, thus decreasing lift and increasing drag, causing roll and yaw. Spoilerons avoid the problem of control reversal that affects ailerons. All modern jet airliners are fitted with inboard lift spoilers which are used together during descent to increase the rate of descent and control speed; some aircraft use lift spoilers on landing approach to control descent without changing the aircraft's attitude.
One jet airliner not fitted with lift spoilers was the Douglas DC-8 which used reverse thrust in flight on the two inboard engines to control descent speed. The Lockheed Tristar was fitted with a system called Direct Lift Control using the spoilers on landing approach to control descent. Airbus aircraft with fly-by-wire control utilise wide-span spoilers for descent control, gust alleviation, lift dumpers. On landing approach, the full width of spoilers can be seen controlling the aircraft's descent rate and bank. Lift dumpers are a special type of spoiler extending along much of the wing's length and designed to dump as much lift as possible on landing. Lift dumpers have only two positions and retracted. Lift dumpers have three main functions: putting most of the weight of the aircraft on the wheels for maximum braking effect, increasing form drag, preventing aircraft'bounce' on landing. Lift dumpers are always deployed automatically on touch down; the flight deck control has three positions: off and manual.
On landing approach'automatic' is selected and, at the moment of touchdown, lift dumpers are deployed in a fraction of a second, with flight control spoilers being raised automatically as additional lift dumpers. All modern jet aircraft are fitted with lift dumpers; the British Aerospace 146 is fitted with wide span spoilers to generate additional drag and make reverse thrust unnecessary. A number of accidents have been caused either by inadvertently deploying lift dumpers on landing approach, or forgetting to set them to'automatic'. Air Canada Flight 621 – Premature deployment of the spoilers at low altitude contributed to this crash in Toronto on 5 July 1970. United Airlines Flight 553 – Forgetting to deactivate the spoilers contributed to crash at Chicago Midway International Airport on 8 December 1972. Loftleiðir Icelandic Airlines Flight 509 – Deployment of lift dumpers while attempting to arm them 40 feet above the runway caused this accident at John F Kennedy International Airport on 23 June 1973.
American Airlines Flight 965 – Forgetting to deactivate the spoilers while climbing to avoid a mountain contributed to this crash on 20 December 1995. American Airlines Flight 1420 – Forgetting to deploy the s
A wing tip is the part of the wing, most distant from the fuselage of a fixed-wing aircraft. Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of shapes, including: Squared-off Aluminium tube bow Rounded Hoerner style Winglets Drooped tips Raked wingtips Tip tanks Sails Fences End platesWinglets have become popular additions to high speed aircraft to increase fuel efficiency by reducing drag from wingtip vortices. In lower speed aircraft, the effect of the wingtip shape is less apparent, with only a marginal performance difference between round and Hoerner style tips The slowest speed aircraft, STOL aircraft, may use wingtips to shape airflow for controlability at low airspeeds. Wing tips are an expression of aircraft design style, so their shape may be influenced by marketing considerations as well as by aerodynamic requirements. Wing tips are used by aircraft designers to mount navigation lights, anti-collision strobe lights, landing lights and identification markings.
Wing tip tanks can distribute weight more evenly across the wing spar. On fighter aircraft, they may be fitted with hardpoints, for mounting drop tanks and weapons systems, such as missiles and electronic countermeasures. Wingtip mounted. Aerobatic aircraft use wingtip mounted crosses for visual attitude reference. Wingtip mounted smoke fireworks highlight rolling aerobatic maneuvers; some airshow acts feature the pilot dragging the wingtip along the ground. Aircraft with a single main landing gear or high aspect ratio wings such as gliders, may place small landing gear in the wingtips; some uncommon designs,like the Rutan Quickie, Convair XFY placed the main landing gear in the wingtips. Some early World War I aircraft used wooded skids on the wingtips to minimize damage on ground looping incidents. Several amphibious aircraft such as the Consolidated PBY Catalina, use retractable wingtips as floats. Moveable wingtips can affect the controlability of a wing. Wing warping the ends of the wing, produced roll control on the earliest of aircraft such as the Wright Flyer.
The North American XB-70 Valkyrie raised and lowered its wingtips in flight to adjust its stability in supersonic and subsonic flight. Wingtips can house the power plant or thrust of an aircraft; the EWR VJ 101 used tip mounted jets, the V-22 uses tilting wingtip mounted engines, the Harrier uses wingtip thrust for stability while hovering. Rotary wing aircraft wingtips may be curved to reduce noise and vibration; some rotary wing aircraft place their propulsion in wingtip tip jets. The Boeing 777X will feature 3.5 m folding wingtips supplied by Liebherr Aerospace from Lindenberg. The mechanism was demonstrated for Aviation Week at the Boeing Everett Factory in October 2016; the folding takes 20 seconds to complete. Wingtip device
The cruciform tail is an aircraft empennage configuration which, when viewed from the aircraft's front or rear, looks much like a cross. The usual arrangement is to have the horizontal stabilizer intersect the vertical tail somewhere near the middle, above the top of the fuselage; the design is used to locate the horizontal stabilizer away from jet exhaust and wing wake, as well as to provide undisturbed airflow to the rudder. Avro Canada CF-100 Canuck British Aerospace Jetstream 31/32 British Aerospace Jetstream 41 Britten-Norman Trislander Canadair CL-215 Cessna A-37 Dragonfly Cessna Citation - Excel and Latitude variants only Cessna T303 Crusader Cessna T-37 Tweet Consolidated PBY Catalina Dassault Falcon 10/100 Dassault Falcon 20/200 Dassault Falcon 50 Dassault Falcon 5X Dassault Falcon 7X Dassault Falcon 8X Dassault Falcon 900 Dassault Falcon 2000 de Havilland Canada DHC-3 Otter Dornier Do 335 Douglas A-4 Skyhawk Fairchild C-26 Metroliner Fairchild Swearingen Metroliner Gloster Meteor Handley Page Jetstream Hawker Hunter Ivanov ZJ-Viera Lake Buccaneer Lockheed JetStar McDonnell FH Phantom McDonnell F2H Banshee - early variants only Messerschmitt 262 Mikoyan-Gurevich MiG-15 Northrop YC-125 Raider Piccard Eureka PZL Bielsko SZD-50 Puchacz Republic F-84 Thunderjet Republic F-84F Thunderstreak/RF-84F Thunderflash Republic XF-84H Thunderscreech Roberts Cygnet Rockwell B-1 Lancer Rockwell Commander 112/114 Scaled Composites White Knight Two Stratos 714 Sud Aviation Caravelle Swearingen Merlin US Aviation Cumulus Westland Whirlwind Pelikan tail T-tail Twin tail V-tail