1.
Boeing B-29 Superfortress
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The Boeing B-29 Superfortress is a four-engine propeller-driven heavy bomber designed by Boeing which was flown primarily by the United States during World War II and the Korean War. It was one of the largest aircraft operational during World War II and it was the single most expensive weapons project undertaken by the United States in World War II, exceeding the cost of the Manhattan Project by between 1 and 1.7 billion dollars. A manned tail gun installation was semi-remote, the name Superfortress continued the pattern Boeing started with its well-known predecessor, the B-17 Flying Fortress. Designed for the strategic bomber role, the B-29 also excelled in low-altitude nighttime incendiary bombing missions. One of the B-29s final roles during World War II was carrying out the bomb attacks on Hiroshima. The B-29 served in roles throughout the 1950s. The Royal Air Force flew the B-29 as the Washington until phasing out the type in 1954, the Soviet Union produced an unlicensed reverse-engineered copy as the Tupolev Tu-4. The B-29 was the progenitor of a series of Boeing-built bombers, transports, tankers, reconnaissance aircraft, the type was retired in the early 1960s. The B-29 production total was 3,970 aircraft, dozens of B-29s remain as static displays but only two examples, Fifi and Doc, have been restored to flying status, with Doc flying again for the first time from McConnell AFB on July 17,2016. A transport developed from the B-29 was the Boeing C-97 Stratofreighter, first flown in 1944, followed by its commercial airliner variant and this bomber-to-airliner derivation was similar to the B-17/Model 307 evolution. In 1948 Boeing introduced a variant of the B-29 as the KB-29. A heavily modified line of outsized-cargo variants of the Stratocruiser is the Guppy / Mini Guppy / Super Guppy which remain in service today with operators including NASA, Boeing began work on pressurized long-range bombers in 1938, in response to a United States Army Air Corps request. Boeings design study for the Model 334 was a derivative of the Boeing B-17 Flying Fortress with nosewheel undercarriage. Although the Air Corps did not have money to pursue the design, in April 1939, Charles Lindbergh convinced general Henry H. Arnold to produce a new bomber in large numbers to counter the Nazi production, Boeings previous private venture studies formed the starting point for its response to this specification. Boeing submitted its Model 345 on 11 May 1940, in competition with designs from Consolidated Aircraft, Lockheed, Consolidated continued to work on its Model 33 as it was seen by the Air Corps as a backup in case of problems with Boeings design. Boeing received a production order for 14 service test aircraft and 250 production bombers in May 1941. The B-29 featured a design with circular cross-section for strength
2.
Boeing B-52 Stratofortress
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The Boeing B-52 Stratofortress is an American long-range, subsonic, jet-powered strategic bomber. The B-52 was designed and built by Boeing, which has continued to provide support and it has been operated by the United States Air Force since the 1950s. The bomber is capable of carrying up to 70,000 pounds of weapons, the B-52 took its maiden flight in April 1952. Built to carry weapons for Cold War-era deterrence missions, the B-52 Stratofortress replaced the Convair B-36. A veteran of wars, the B-52 has dropped only conventional munitions in combat. The B-52s official name Stratofortress is rarely used, informally, the aircraft has become referred to as the BUFF. The B-52 has been in service with the USAF since 1955. As of December 2015,58 were in service with 18 in reserve. The B-52 completed sixty years of service with its original operator in 2015. After being upgraded between 2013 and 2015, it is expected to serve into the 2040s, the aircraft was to have a crew of five or more turret gunners, and a six-man relief crew. It was required to cruise at 300 mph at 34,000 feet with a radius of 5,000 miles. The armament was to consist of a number of 20 mm cannon and 10,000 pounds of bombs. On 13 February 1946, the Air Force issued bid invitations for these specifications, with Boeing, Consolidated Aircraft, and Glenn L. Martin Company submitting proposals. On 5 June 1946, Boeings Model 462, an aircraft powered by six Wright T35 turboprops with a gross weight of 360,000 pounds. On 28 June 1946, Boeing was issued a letter of contract for US$1.7 million to build a full-scale mock-up of the new XB-52 and do preliminary engineering and testing. However, by October 1946, the air began to express concern about the sheer size of the new aircraft. In response, Boeing produced Model 464, a smaller version with a 230,000 pound gross weight. Boeing responded with two powered by the T-35 turboprops
3.
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
4.
Missile
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In modern language, a missile is a self-propelled precision-guided munition system, as opposed to an unguided self-propelled munition, referred to as a rocket. Missiles have four components, targeting and/or missile guidance, flight system, engine. Missiles come in types adapted for different purposes, surface-to-surface and air-to-surface missiles, surface-to-air missiles, air-to-air missiles, all known existing missiles are designed to be propelled during powered flight by chemical reactions inside a rocket engine, jet engine, or other type of engine. Non-self-propelled airborne explosive devices are referred to as shells and usually have a shorter range than missiles. In ordinary British-English usage predating guided weapons, a missile is any thrown object, the word missile comes from the Latin verb mittere, meaning to send. In military usage, munitions projected towards a target are broadly categorised as follows, a powered, unguided munition is known as a rocket. Unpowered munitions not fired from a gun are called bombs whether guided or not, munitions that are fired from a gun are known as projectiles whether guided or not. If explosive, they are more specifically as shells or mortar bombs. Powered munitions that travel through water are called torpedoes, hand grenades are not usually classed as missiles. The first missiles to be used operationally were a series of missiles developed by Nazi Germany in World War II, most famous of these are the V-1 flying bomb and V-2 rocket, both of which used a simple mechanical autopilot to keep the missile flying along a pre-chosen route. Less well known were a series of anti-shipping and anti-aircraft missiles, however, these early systems in World War II were only built in small numbers. Guided missiles have a number of different system components, Targeting and/or missile guidance Flight system Engine Warhead Missiles may be targeted in a number of ways. The most common method is to use some form of radiation, such as infrared, lasers or radio waves and this radiation may emanate from the target, it may be provided by the missile itself, or it may be provided by a friendly third party. The first two are known as fire-and-forget as they need no further support or control from the launch vehicle/platform in order to function. Another method is to use a TV guidance—using either visible light or infrared—in order to see the target, the picture may be used either by a human operator who steers the missile onto its target or by a computer doing much the same job. One of the more bizarre guidance methods instead used a pigeon to steer the missile to its target, many missiles use a combination of two or more of the above methods to improve accuracy and the chances of a successful engagement. Another method is to target the missile by knowing the location of the target and using a system such as INS. This guidance system guides the missile by knowing the current position and the position of the target
5.
Bomb
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A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Bombs have been in use since the 11th century in Song Dynasty China, the term bomb is not usually applied to explosive devices used for civilian purposes such as construction or mining, although the people using the devices may sometimes refer to them as a bomb. The military use of the bomb, or more specifically aerial bomb action, typically refers to airdropped, unpowered explosive weapons most commonly used by air forces. Other military explosive weapons not classified as bombs include grenades, shells, depth charges, warheads when in missiles, in unconventional warfare, other names can refer to a range of offensive weaponry. For instance, in recent Middle Eastern conflicts, bombs called improvised explosive devices have been employed by insurgent fighters to great effectiveness, the word comes from the Latin bombus, which in turn comes from the Greek βόμβος, an onomatopoetic term meaning booming, buzzing. Explosive bombs were used in China in 1221, by a Jin dynasty army against a Song Dynasty city, Bombs built using bamboo tubes appear in the 11th century. Bombs made of cast iron shells packed with explosive gunpowder date to 13th century China, the term was coined for this bomb during a Jin dynasty naval battle of 1231 against the Mongols. When hit, even iron armour was pierced through. The Ming Dynasty text Huolongjing describes the use of gunpowder bombs. During the Mongol invasions of Japan, the Mongols used the explosive thunder-crash bombs against the Japanese, archaeological evidence of the thunder-crash bombs has been discovered in an underwater shipwreck off the shore of Japan by the Kyushu Okinawa Society for Underwater Archaeology. X-rays by Japanese scientists of the excavated shells confirmed that they contained gunpowder, explosive shock waves can cause situations such as body displacement, dismemberment, internal bleeding and ruptured eardrums. Shock waves produced by explosive events have two components, the positive and negative wave. The positive wave shoves outward from the point of detonation, followed by the vacuum space sucking back towards the point of origin as the shock bubble collapses. The greatest defense against shock injuries is distance from the source of shock, as a point of reference, the overpressure at the Oklahoma City bombing was estimated in the range of 28 MPa. A thermal wave is created by the release of heat caused by an explosion. Military bomb tests have documented temperatures of up to 2,480 °C, while capable of inflicting severe to catastrophic burns and causing secondary fires, thermal wave effects are considered very limited in range compared to shock and fragmentation. This would be fatal to humans, as tests have proven. Fragmentation is produced by the acceleration of shattered pieces of bomb casing, the use of fragmentation in bombs dates to the 14th century, and appears in the Ming Dynasty text Huolongjing
6.
Fuselage
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The fuselage is an aircrafts main body section. It holds crew, passengers, and cargo, the fuselage also serves to position control and stabilization surfaces in specific relationships to lifting surfaces, which is required for aircraft stability and maneuverability. This type of structure is still in use in lightweight aircraft using welded steel tube trusses. A box truss fuselage structure can also be out of wood—often covered with plywood. Simple box structures may be rounded by the addition of supported lightweight stringers, allowing the fabric covering to form an aerodynamic shape. Geodesic structural elements were used by Barnes Wallis for British Vickers between the wars and into World War II to form the whole of the fuselage, including its aerodynamic shape. In this type of construction multiple flat strip stringers are wound about the formers in opposite spiral directions and this proved to be light, strong, and rigid and had the advantage of being made almost entirely of wood. A similar construction using aluminum alloy was used in the Vickers Warwick with less materials than would be required for other structural types, the geodesic structure is also redundant and so can survive localized damage without catastrophic failure. A fabric covering over the completed the aerodynamic shell. The logical evolution of this is the creation of fuselages using molded plywood, in this method, the exterior surface of the fuselage is also the primary structure. A typical early form of this was built using molded plywood, a later form of this structure uses fiberglass cloth impregnated with polyester or epoxy resin, instead of plywood, as the skin. An example of a larger molded plywood aircraft is the de Havilland Mosquito fighter/light bomber of World War II, no plywood-skin fuselage is truly monocoque, since stiffening elements are incorporated into the structure to carry concentrated loads that would otherwise buckle the thin skin. The use of molded fiberglass using negative molds is prevalent in the production of many modern sailplanes. The use of molded composites for fuselage structures is being extended to large aircraft such as the Boeing 787 Dreamliner. This is the method of constructing an all-aluminum fuselage. First, a series of frames in the shape of the cross sections are held in position on a rigid fixture. These frames are then joined with lightweight longitudinal elements called stringers and these are in turn covered with a skin of sheet aluminum, attached by riveting or by bonding with special adhesives. The fixture is then disassembled and removed from the fuselage shell, which is then fitted out with wiring, controls
7.
Slip (aerodynamics)
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A slip is an aerodynamic state where an aircraft is moving somewhat sideways as well as forward relative to the oncoming airflow or relative wind. In other words, for a aircraft, the nose will be pointing in the opposite direction to the bank of the wing. The aircraft is not in coordinated flight and therefore is flying inefficiently, Flying in a slip is aerodynamically inefficient, since the lift-to-drag ratio is reduced. More drag is at play consuming energy but not producing lift, inexperienced or inattentive pilots will often enter slips unintentionally during turns by failing to coordinate the aircraft with the rudder. Airplanes can readily enter into a slip climbing out from take-off on a windy day, if left unchecked, climb performance will suffer. This is especially dangerous if there are nearby obstructions under the climb path, a slip can also be a piloting maneuver where the pilot deliberately enters one type of slip or another. Slips are particularly useful in performing a short field landing over an obstacle, or to avoid an obstacle and these methods are also commonly employed when flying into farmstead or rough country airstrips where the landing strip is short. Pilots need to touch down with ample runway remaining to slow down, there are common situations where a pilot may deliberately enter a slip by using opposite rudder and aileron inputs, most commonly in a landing approach at low power. Without flaps or spoilers it is difficult to increase the steepness of the glide without adding significant speed and this excess speed can cause the aircraft to fly in ground effect for an extended period, perhaps running out of runway. In a forward slip much more drag is created, allowing the pilot to dissipate altitude without increasing airspeed, forward slips are especially useful when operating pre-1950s training aircraft, aerobatic aircraft such as the Pitts Special or any aircraft with inoperative flaps or spoilers. Often, if an airplane in a slip is made to stall, a stalling airplane in a slip may do little more than tend to roll into a wings-level attitude. In fact, in some airplanes stall characteristics may even be improved, aerodynamically these are identical once established, but they are entered for different reasons and will create different ground tracks and headings relative to those prior to entry. Forward-slip is used to steepen an approach without gaining much airspeed, the sideslip moves the aircraft sideways where executing a turn would be inadvisable, drag is considered a byproduct. Most pilots like to enter sideslip just before flaring or touching down during a crosswind landing, the forward slip changes the heading of the aircraft away from the down wing, while retaining the original track of the aircraft. To execute a forward slip, the banks into the wind. If you were the target you would see the planes nose off to one side, the pilot must make sure that the planes nose is low enough to keep airspeed up. However, airframe speed limits such as VA and VFE must be observed, a forward-slip is useful when a pilot has set up for a landing approach with excessive height or must descend steeply beyond a tree line to touchdown near the runway threshold. Assuming that the plane is properly lined up for the runway, in the United States, student pilots are required to know how to do forward slips before embarking on their first solo flight
8.
Skeg
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A skeg, is a sternward extension of the keel of boats and ships which have a rudder mounted on the centre line. The term also applies to the lowest point on a motor or the outdrive of an inboard/outboard. In more recent years, the name has been used for a fin on a surfboard which improves directional stability, the term is also often used for the fin on water skis in the U. S. and for the tail bumpers of aircraft in the US Navy. The word originates in the Scandinavian word for beard, in Old Norse, in Icelandic the word remains skegg, in modern Norwegian Bokmål and Nynorsk, it appears as skjegg, in Swedish, it is skägg and in Danish, skæg. The Norwegian pronunciation of the letter combination skj is as in the English sh, the word is related to the English shaggy. It also appears in the English place name Skegness - beard point, from the way in which a series of tombolos forms, here, the English pronunciation reflects a probable Danish origin, which pronounces the sk letter combination as an English speaker would expect. Where a vessels rudder is mounted on the centre-line, it is usual to hang it on gudgeons and pintles, the latter being upright pins and the former, rings to fit round them. This naturally leaves a gap between the sternpost and the rudder, into which stray items like kelp and rope can catch, causing drag. In ships such as Mary Rose, the skeg is a small feature. This somewhat beard-like sternward extension of the keel is the basic skeg, subsequently, the lowest pintle was commonly mounted below the rudder on a metal extension of the keel. This helped further stabilize and protect the rudder and the name skeg was transferred to it and it used to be relatively small until screw propellers were introduced, when it had to reach below the screw and became a proportionately larger feature protecting both screw and rudder from damage. On wooden vessels, the skeg may be protected from damage by the addition of a bug shoe. In more modern installations, with more than one screw, a fitting supports each propeller shaft just ahead of its screw. This is usually called a shaft bracket but the part of it extends below the shaft bearing to protect the lower part of the propeller is also a skeg. Similarly, the projection of the drive casing, below the rotational axis of the propeller of an outboard motor is another form of the skeg. Where a yacht is designed with a fin keel, it will normally and this link shows the profile of such a boat. This type of skeg is pictured at the bottom of the linked page. In surfing, windsurfing, and kitesurfing, skegs, usually known as fins, are attached toward the tail of the board to improve directional stability, fins allow the rider to control the boards direction by varying their side-to-side weight distribution
9.
Empennage
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The empennage, also known as the tail or tail assembly, provides stability for aircraft, in a way similar to the feathers on an arrow. The term derives from the French language word empenner which means to feather an arrow, most aircraft feature an empennage incorporating vertical and horizontal stabilising surfaces which stabilise the flight dynamics of yaw and pitch, as well as housing control surfaces. In spite of effective control surfaces, many aircraft that lacked a stabilising empennage were virtually unflyable. Even so-called tailless aircraft usually have a tail fin, heavier-than-air aircraft without any kind of empennage are rare. Structurally, the empennage consists of the tail assembly, including the tailfin, the tailplane. On an airliner this would be all the flying and control surfaces behind the pressure bulkhead. The front section of the tailplane is called the tailplane or horizontal stabiliser and is used to pitch stability. The rear section is called the elevator, and is hinged to the horizontal stabiliser. The elevator is a movable aerofoil that controls changes in pitch, some aircraft employ an all-moving stabiliser and elevators in one unit, known as a stabilator or full-flying stabiliser. The vertical tail structure has a front section called the vertical stabiliser. The rear section of the fin is the rudder, a movable aerofoil that is used to turn the aircrafts nose to one side or the other. When used in combination with the ailerons, the result is a banking turn, some aircraft are fitted with a tail assembly that is hinged to pivot in two axes forward of the fin and stabiliser, in an arrangement referred to as a movable tail. The entire empennage is rotated vertically to actuate the horizontal stabiliser, in some aircraft trim devices are provided to eliminate the need for the pilot to maintain constant pressure on the elevator or rudder controls. The trim device may be, a tab on the rear of the elevators or rudder which act to change the aerodynamic load on the surface. Usually controlled by a wheel or crank. an adjustable stabiliser into which the stabiliser may be hinged at its spar. Usually controlled by a cockpit crank, a bungee trim system which uses a spring to provide an adjustable preload in the controls. Usually controlled by a cockpit lever, an anti-servo tab used to trim some elevators and stabilators as well as increased control force feel. Usually controlled by a wheel or crank
10.
Positive feedback
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Positive feedback is a process that occurs in a feedback loop in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation. That is, A produces more of B which in turn more of A. In contrast, a system in which the results of an act to reduce or counteract it has negative feedback. Both concepts play an important role in science and engineering, including biology, chemistry, mathematically, positive feedback is defined as a positive loop gain around a closed loop of cause and effect. That is, positive feedback is in phase with the input, Positive feedback tends to cause system instability. When the loop gain is positive and above 1, there will typically be exponential growth, increasing oscillations, system parameters will typically accelerate towards extreme values, which may damage or destroy the system, or may end with the system latched into a new stable state. Positive feedback may be controlled by signals in the system being filtered, damped, or limited, Positive feedback is used in digital electronics to force voltages away from intermediate voltages into 0 and 1 states. On the other hand, thermal runaway is a positive feedback that can destroy semiconductor junctions, Positive feedback in chemical reactions can increase the rate of reactions, and in some cases can lead to explosions. Positive feedback in mechanical design causes tipping-point, or over-centre, mechanisms to snap into position, for example in switches, out of control, it can cause bridges to collapse. Positive feedback in systems can cause boom-then-bust cycles. Positive feedback enhances or amplifies an effect by it having an influence on the process gave rise to it. For example, when part of an output signal returns to the input, and is in phase with it. The feedback from the outcome to the process can be direct. Such systems can give rich qualitative behaviors, but whether the feedback is positive or negative in sign has an extremely important influence on the results. Positive feedback reinforces and negative feedback moderates the original process, Positive and negative in this sense refer to loop gains greater than or less than zero, and do not imply any value judgements as to the desirability of the outcomes or effects. A key feature of positive feedback is thus that small disturbances get bigger, when a change occurs in a system, positive feedback causes further change, in the same direction. A simple feedback loop is shown in the diagram, if the loop gain AB is positive, then a condition of positive or regenerative feedback exists. If the functions A and B are linear and AB is smaller than unity, then the system gain from the input to output is finite
11.
Relaxed stability
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In aviation, relaxed stability is the tendency of an aircraft to change its attitude and angle of bank of its own accord. An aircraft with relaxed stability will oscillate in simple harmonic motion around a particular attitude at an increasing amplitude, a positively stable aircraft will also resist any bank movement. A Cessna 152 is an example of a stable aircraft, early attempts at heavier-than-air flight were marked by a differing concept of stability than is used today. Most aeronautical investigators regarded flight as if it were not so different from surface locomotion and they thought of changing direction in terms of a ships rudder, so the flying machine would remain essentially level in the air, as did an automobile or a ship at the surface. The idea of deliberately leaning, or rolling, to one side either seemed undesirable or did not enter their thinking and they achieved this with the help of Hargrave cellular wings and strongly dihedral wings. In most cases they did not include any means for a pilot to control the aircraft roll — they could only control elevator, the unpredicted effect of this was that it was very hard to turn the aircraft without rolling. They were also affected by side gusts and side winds upon landing. The Wright brothers designed their 1903 first powered Flyer with anhedral wings, which are inherently unstable. They showed that a pilot can maintain control of lateral roll, equally important, this method would enable recovery when the wind tilted the machine to one side. The vertical positioning of the changes the roll stability of an aircraft. An aircraft with a high wing position has a higher roll stability, an aircraft with a low wing has less roll stability. The Piper Pawnee uses a low wing, modern military aircraft, particularly low observable designs, often exhibit instability as a result of their shape. However, the facets of the design reduce its stability to the point where a computerized fly-by-wire system was required to allow safe operation. Relaxed stability designs are not limited to military jets, the McDonnell Douglas MD-11 has a relaxed stability design which was implemented to save fuel. To ensure stability for safe flight, an LSAS was introduced to compensate for the MD-11s rather short horizontal stabilizer, however, there have been incidents in which the MD-11s relaxed stability caused an inflight upset. The latest generation of fighter aircraft often employ design elements which reduce stability to increase maneuverability, greater stability leads to lesser control surface authority, therefore a less stable design will have a faster response to control inputs. This is highly sought after in fighter aircraft design, the BAE Harrier GR7/GR9 employs a significant and obvious anhedral angle to its wings, reducing the inherent lateral stability of the wings mounted high on the fuselage. Crouch, Tom D, The Bishops Boys, A Life of Wilbur and Orville Wright, New York, WW Norton & Co, ISBN 0-393-30695-X
12.
Rudder
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A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other conveyance that moves through a fluid medium. On an aircraft the rudder is used primarily to counter adverse yaw, 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 plane or sheet of material attached with hinges to the crafts stern, tail. Often 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, cables, pushrods, or hydraulics may be used to link rudders to steering wheels, in typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics. Generally, a rudder is part of the apparatus of a boat or ship that is fastened outside the hull, that is denoting all different types of oars, paddles. More specifically, the gear of ancient vessels can be classified into side-rudders and stern-mounted rudders. A third term, steering oar, can denote both types, in a Mediterranean context, side-rudders are more specifically called quarter-rudders as the later term designates more exactly the place where the rudder was mounted. Stern-mounted rudders are uniformly suspended at the back of the ship in a central position. S, a steering oar was used at this time because the rudder had not yet been invented. With a single sail, a frequent movement of the oar was required to steer a straight course. The steering oar or steering board is an oar or board to control the direction of a ship or other watercraft prior to the invention of the rudder. It is normally attached to the side in larger vessels, though in smaller ones it is rarely, if ever. Rowing oars set aside for steering appeared on large Egyptian vessels long before the time of Menes, in the Old Kingdom as much 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, both the tiller and the introduction of an upright steering post abaft reduced the usual number of necessary steering oars to one each side. In Iran, oars mounted on the side of ships for steering are documented from the 3rd millennium BCE in artwork, wooden models, the strength of the steering oar lay in its combination of effectiveness, adaptability and simpleness. Roman quarter steering oar mounting systems survived mostly intact through the medieval period, by the first half of the 1st century AD, steering gear mounted on the stern were also 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, interestingly, the boat already 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, also, the well-known Zwammerdam find, a large river barge at the mouth of the Rhine, featured a large steering gear mounted on the stern
13.
Aircraft principal axes
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The axes are alternatively designated as lateral, vertical, and longitudinal. These axes move with the vehicle and rotate relative to the Earth along with the craft and these definitions were analogously applied to spacecraft when the first manned spacecraft were designed in the late 1950s. These rotations are produced by torques about the principal axes, on an aircraft, these are intentionally produced by means of moving control surfaces, which vary the distribution of the net aerodynamic force about the vehicles center of mass. Elevators produce pitch, a rudder on the vertical tail produces yaw, on a spacecraft, the moments are usually produced by a reaction control system consisting of small rocket thrusters used to apply asymmetrical thrust on the vehicle. Normal axis, or yaw axis — an axis drawn from top to bottom, lateral axis, transverse axis, or pitch axis — an axis running from the pilots left to right in piloted aircraft, and parallel to the wings of a winged aircraft. Longitudinal axis, or roll axis — an axis drawn through the body of the vehicle from tail to nose in the direction of flight. Normally, these axes are represented by the letters X, Y and Z in order to them with some reference frame. Normally, this is made in such a way that the X is used for the longitudinal axis, but there are other possibilities to do it. The vertical yaw axis is defined to be perpendicular to the wings and to the line of flight with its origin at the center of gravity. Yaw moves the nose of the aircraft from side to side, a positive yaw, or heading angle, moves the nose to the right. The rudder is the control of yaw. The pitch axis passes through the plane from wingtip to wingtip, pitch moves the aircrafts nose up and down. A positive pitch angle raises the nose and lowers the tail, the elevators are the primary control of pitch. The roll axis passes through the plane from nose to tail, the angular displacement about this axis is called bank. The pilot changes bank angle by increasing the lift on one wing and decreasing it on the other, a positive roll angle lifts the left wing and lowers the right wing. The ailerons are the control of bank. The rudder also has an effect on bank. These axes are related to the axes of inertia, but are not the same
14.
Radio navigation
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Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth. Like radiolocation, it is a type of radiodetermination and these systems used some form of directional radio antenna to determine the location of a broadcast station on the ground. Conventional navigation techniques are used to take a radio fix. These were introduced prior to World War I, and remain in use today, the first system of radio navigation was the Radio Direction Finder, or RDF. By tuning in a station and then using a directional antenna. A second measurement using another station was then taken, using triangulation, the two directions can be plotted on a map where their intersection reveals the location of the navigator. Early RDF systems normally used an antenna, a small loop of metal wire that is mounted so it can be rotated around a vertical axis. By rotating the loop and looking for the angle of the null, loop antennas can be seen on most pre-1950s aircraft and ships. The main problem with RDF is that it required a special antenna on the vehicle, a smaller problem is that the accuracy of the system is based to a degree on the size of the antenna, but larger antennas would likewise make the installation more difficult. During the era between World War I and World War II, a number of systems were introduced that placed the antenna on the ground. Then they waited for the signal to either peak or disappear as the antenna pointed in their direction. By timing the delay between the signal and the peak/null, then dividing by the known rotational rate of the station. The first such system was the German Telefunken Kompass Sender, which operations in 1907 and was used operationally by the Zeppelin fleet until 1918. An improved version was introduced by the UK as the Orfordness Beacon in 1929, a number of improved versions followed, replacing the mechanical motion of the antennas with phasing techniques that produced the same output pattern with no moving parts. One of the longest lasting examples was Sonne, which went into operation just before World War II, the modern VOR system is based on the same principles. A great advance in the RDF technique was introduced in the form of phase comparisons of a signal as measured on two or more antennas, or a single highly directional solenoid. These receivers were dramatically smaller, more accurate, and simpler to operate and this also led to a revival in the operation of simple radio beacons for use with these RDF systems, now referred to as non-directional beacons. As the LF/MF signals used by NDBs can follow the curvature of earth, NDB can be categorized as long range or short range depending on their power
15.
Airband
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Different sections of the band are used for radionavigational aids and air traffic control. In most countries a license to operate airband equipment is required and the operator is tested on competency in procedures, language, the VHF airband uses the frequencies between 108 and 137 MHz. The lowest 10 MHz of the band, from 108–117.95 MHz, is split into 200 narrow-band channels of 50 kHz and these are reserved for navigational aids such as VOR beacons, and precision approach systems such as ILS localizers. As of 2012, most countries divide the upper 19 MHz into 760 channels for amplitude modulation voice transmissions, on frequencies from 118–136.975 MHz, in Europe, it is becoming common to further divide those channels into three, potentially permitting 2,280 channels. Some channels between 123.100 and 135, a typical transmission range of an aircraft flying at cruise altitude, is about 200 mi in good weather conditions. Aeronautical voice communication is conducted in other frequency bands, including satellite voice on Inmarsat or Iridium. Usually these other bands are only used in oceanic and remote areas. Military aircraft also use a dedicated UHF-AM band from 225. 0–399.95 MHz for air-to-air and air-to-ground and this band has a designated emergency and guard channel of 243.0 MHz. The ILS glide path operates in the UHF frequency range of 329. 3–335.0 MHz, channel spacing for voice communication on the airband was originally 200 kHz until 1947, providing 70 channels from 118 to 132 MHz. Some radios of that time provided receive-only coverage below 118 MHz for a total of 90 channels. From 1947–1958 the spacing became 100 kHz, from 1954 split once again to 50 kHz and the limit extended to 135.95 MHz. On 1 January 1990 the frequencies between 136.000 and 136.975 MHz were added, resulting in 760 channels, outside of Europe,8.33 kHz channels are permitted in many countries but not widely used as of 2012. The emergency communication channel 121.5 MHz is the channel that retains 100 kHz channel spacing in the US. Besides being simple, power-efficient and compatible with legacy equipment, AM, additionally, this method does not suffer from the capture effect found in FM. Even if a pilot is transmitting, a tower can talk over that transmission. Even if both transmissions are received with identical signal strength, a heterodyne will be heard where no such indication of blockage would be evident in an FM system. Alternative analog modulation schemes are under discussion, such as the CLIMAX multi-carrier system, the audio quality in the airband is limited by the RF bandwidth used. In the newer channel spacing scheme, the largest bandwidth of a channel might be limited to 8.33 kHz
16.
Transceiver
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A transceiver is a device comprising both a transmitter and a receiver that are combined and share common circuitry or a single housing. When no circuitry is common between transmit and receive functions, the device is a transmitter-receiver, the term originated in the early 1920s. Similar devices include transponders, transverters, and repeaters, in radio terminology, a transceiver means a unit which contains both a receiver and a transmitter. From the beginning days of radio the receiver and transmitter were separate units, amateur radio or ham radio operators can build their own equipment and it is now easier to design and build a simple unit containing both of the functions, transmitting and receiving. Almost all modern radio equipment is now a transceiver but there is an active market for pure radio receivers. An example of a transceiver would be a walkie-talkie or a CB radio, on a wired telephone, the handset contains the transmitter and receiver for the audio and in the 20th century was usually wired to the base unit by tinsel wire. The whole unit is referred to as a receiver. On a mobile telephone or other radiotelephone, the unit is a transceiver. A cordless telephone uses an audio and radio transceiver for the handset, if a speakerphone is included in a wired telephone base or in a cordless base station, the base also becomes an audio transceiver in addition to the handset. A modem is similar to a transceiver, in that it sends and receives a signal and it modulates a signal being transmitted and demodulates a signal being received. Transceivers are called Medium Attachment Units in IEEE802.3 documents and were used in 10BASE2. Fiber-optic gigabit,10 Gigabit Ethernet,40 Gigabit Ethernet, and 100 Gigabit Ethernet utilize transceivers known as GBIC, SFP, SFP+, QSFP, XFP, XAUI, CXP, and CFP. 4P4C, de facto standard connector for telephone handsets Duplex, two-Way communications capability Transponder#Optical communications U. S, patent 0,716,136, John Stone Stone, Apparatus for simultaneously transmitting and receiving space telegraph signals 7 MHz SSB transceiver Homebrew HF transceivers
17.
Antenna (radio)
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In radio and electronics, an antenna, or aerial, is an electrical device which converts electric power into radio waves, and vice versa. It is usually used with a transmitter or radio receiver. In reception, an antenna intercepts some of the power of a wave in order to produce a tiny voltage at its terminals. Antennas are essential components of all equipment that uses radio, typically an antenna consists of an arrangement of metallic conductors, electrically connected to the receiver or transmitter. These time-varying fields radiate away from the antenna into space as a transverse electromagnetic field wave. Antennas can be designed to transmit and receive radio waves in all directions equally. The first antennas were built in 1888 by German physicist Heinrich Hertz in his experiments to prove the existence of electromagnetic waves predicted by the theory of James Clerk Maxwell. Hertz placed dipole antennas at the point of parabolic reflectors for both transmitting and receiving. He published his work in Annalen der Physik und Chemie, the words antenna and aerial are used interchangeably. Occasionally the term aerial is used to mean a wire antenna, however, note the important international technical journal, the IEEE Transactions on Antennas and Propagation. In the United Kingdom and other areas where British English is used, the origin of the word antenna relative to wireless apparatus is attributed to Italian radio pioneer Guglielmo Marconi. In the summer of 1895, Marconi began testing his wireless system outdoors on his fathers estate near Bologna, Marconi discovered that by raising the aerial wire above the ground and connecting the other side of his transmitter to ground, the transmission range was increased. Soon he was able to transmit signals over a hill, a distance of approximately 2.4 kilometres, in Italian a tent pole is known as lantenna centrale, and the pole with the wire was simply called lantenna. Until then wireless radiating transmitting and receiving elements were simply as aerials or terminals. Because of his prominence, Marconis use of the word spread among wireless researchers. In common usage, the antenna may refer broadly to an entire assembly including support structure, enclosure. Especially at microwave frequencies, an antenna may include not only the actual electrical antenna. An antenna, in converting radio waves to electrical signals or vice versa, is a form of transducer, Antennas are required by any radio receiver or transmitter to couple its electrical connection to the electromagnetic field
18.
Trijet
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A trijet is a jet aircraft powered by three jet engines. In general, passenger airline trijets are considered to be second-generation jet airliners, due to their innovative engine locations, other variations of three-engine designs are trimotors, which are aircraft with three piston engines. One issue with trijets is positioning the central engine, on most trijets they are placed at the tail along the middle, producing some technical difficulties. The central engine is most commonly supplied with air by an S-shaped duct – this is used on the Hawker Siddeley Trident, Boeing 727, Tupolev Tu-154, an S-duct has the advantage of reduced drag. Additionally, since the engine outlet is located lower down, the aircraft will be easier to handle in the event of an engine failure, however, S-ducts are complicated and costly designs. Since the engine outlet is located higher up than the wing mounted engines. Placement of the two engines varies. However, the difficulty and complexity of mounting the engine through the tail in a trijet design will somewhat negate this advantage. The main disadvantage with trijets is fuel efficiency, as a design will almost always consume more fuel than a comparable twin engine design. The first three-jet design to fly was the Martin XB-51 ground attack aircraft, the first commercial trijets were the Hawker Siddeley Trident and the Boeing 727. Both were compromises to meet requirements, in the case of the Trident it was to meet BEAs changing needs. Although collaboration between the manufacturers was considered, it did not come about, in 1964, this rule was lifted for trijet designs, as they had a greater safety margin. Thus trijet designs such as the DC-10 and L-1011 represented the best compromise with medium- to long range and medium size that US airlines sought for their domestic and transatlantic routes. As a result of these trijet wide-bodies, as well as the popularity of the Boeing 727, from 1985 to 2003 the number of such planes in service had sunk from 1488 to 602. The number of twin-jets had more than quadrupled in the same period, McDonnell Douglas had planned a new series of DC-10 family trijets called the MD-XX, which were lengthened versions of the MD-11. The MD-XX Long Range would have been capable of travelling distances up to 8,320 nautical miles and had a span of 213 feet. The project was cancelled in 1996, one year before McDonnell Douglas was acquired by Boeing, the MD-11s long range advantage was brief as it was soon nullified by the Airbus A330s four-engine derivative, the Airbus A340, and the extended-range Boeing 767-300ER and Boeing 777-200ER. Modern engines have extremely low rates and increased power output
19.
Car
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A car is a wheeled, self-powered motor vehicle used for transportation and a product of the automotive industry. The year 1886 is regarded as the year of the modern car. In that year, German inventor Karl Benz built the Benz Patent-Motorwagen, cars did not become widely available until the early 20th century. One of the first cars that was accessible to the masses was the 1908 Model T, an American car manufactured by the Ford Motor Company. Cars were rapidly adopted in the United States of America, where they replaced animal-drawn carriages and carts, cars are equipped with controls used for driving, parking, passenger comfort and safety, and controlling a variety of lights. Over the decades, additional features and controls have been added to vehicles, examples include rear reversing cameras, air conditioning, navigation systems, and in car entertainment. Most cars in use in the 2010s are propelled by a combustion engine. Both fuels cause air pollution and are blamed for contributing to climate change. Vehicles using alternative fuels such as ethanol flexible-fuel vehicles and natural gas vehicles are also gaining popularity in some countries, electric cars, which were invented early in the history of the car, began to become commercially available in 2008. There are costs and benefits to car use, the costs of car usage include the cost of, acquiring the vehicle, interest payments, repairs and auto maintenance, fuel, depreciation, driving time, parking fees, taxes, and insurance. The costs to society of car use include, maintaining roads, land use, road congestion, air pollution, public health, health care, road traffic accidents are the largest cause of injury-related deaths worldwide. The benefits may include transportation, mobility, independence. The ability for humans to move flexibly from place to place has far-reaching implications for the nature of societies and it was estimated in 2010 that the number of cars had risen to over 1 billion vehicles, up from the 500 million of 1986. The numbers are increasing rapidly, especially in China, India, the word car is believed to originate from the Latin word carrus or carrum, or the Middle English word carre. In turn, these originated from the Gaulish word karros, the Gaulish language was a branch of the Brythoic language which also used the word Karr, the Brythonig language evolved into Welsh where Car llusg and car rhyfel still survive. It originally referred to any wheeled vehicle, such as a cart, carriage. Motor car is attested from 1895, and is the formal name for cars in British English. Autocar is a variant that is attested from 1895
20.
Formula One
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Formula One is the highest class of single-seat auto racing that is sanctioned by the Fédération Internationale de lAutomobile. The FIA Formula One World Championship has been the form of racing since the inaugural season in 1950. The formula, designated in the name, refers to a set of rules, the F1 season consists of a series of races, known as Grands Prix, held worldwide on purpose-built F1 circuits and public roads. The results of each race are evaluated using a system to determine two annual World Championships, one for drivers, one for constructors. The racing drivers are required to be holders of valid Super Licences, the races are required to be held on tracks graded 1, the highest grade a track can receive by the FIA. Most events are held in locations on purpose-built tracks, but there are several events in city centres throughout the world. Formula One cars are the fastest road racing cars in the world. Formula One cars race at speeds of up to approximately 375 km/h with engines currently limited in performance to a maximum of 15,000 RPM, the cars are capable of lateral acceleration in excess of five g in corners. The performance of the cars is very dependent on electronics – although traction control and other driving aids have been banned since 2008 – and on aerodynamics, suspension, the formula has radically evolved and changed through the history of the sport. F1 had a global television audience of 425 million people during the course of the 2014 season. Grand Prix racing began in 1906 and became the most popular internationally in the second half of the twentieth century. The Formula One Group is the holder of the commercial rights. Its high profile and popularity have created a major merchandising environment, since 2000 the sports spiraling expenditures and the distribution of prize money favoring established top teams have forced complaints from smaller teams and led several teams to bankruptcy. On 23 January 2017 it was confirmed that Liberty Media had completed its $8 billion acquisition of Delta Topco, the Formula One series originated with the European Grand Prix Motor Racing of the 1920s and 1930s. The formula is a set of rules that all cars must meet. Formula One was a new formula agreed upon after World War II during 1946, the first world championship race was held at Silverstone, United Kingdom in 1950. A championship for constructors followed in 1958, national championships existed in South Africa and the UK in the 1960s and 1970s. Non-championship Formula One events were held for years, but due to the increasing cost of competition
21.
Le Mans Prototype
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Le Mans Prototypes were created by the Automobile Club de lOuest. The technical requirements for an LMP include bodywork covering all mechanical elements of the car, while not as fast as open-wheel Formula One cars, LMPs are the fastest closed-wheel racing cars used in circuit racing. Le Mans Prototypes are considered a class above production-based grand tourer cars, modern LMP designs include hybrid cars that use electric motors to assist acceleration. Le Mans Prototypes have used various names depending on the series in which they compete, the FIAs equivalent cars were referred to as Sports Racers or Sports Racing Prototypes. The American IMSA GT Championship termed their cars World Sports Cars, since 2004, most series have switched to referring to these cars as Le Mans Prototypes. The American Le Mans Series, the successor to the IMSA GT Championship, an LMP is commonly referred to as a Le Mans car in the media. The first use of what would become Le Mans Prototypes was at the 199224 Hours of Le Mans. In an attempt to increase the number of entrants beyond the field of Group C competitors that the World Sportscar Championship had to offer, older Porsche 962s were allowed entry in Category 3. To further increase the size of the field, small open-cockpit race cars using production road car engines which were raced in national championships, were allowed in Category 4. Only three cars were entered, with all failing to run more than a few hours. With Group C being phased out, the ACO chose to allow production-based race cars to enter for the first time in many years, the cars continued to use the same formula as they had in 1992. Later, ACO announced their intentions to replace the Group C cars with Le Mans Prototypes in 1994. Both classes were required to have open cockpits and this formula continued up to 1996, with many manufacturers embracing the LMP and WSC classes, including Ferrari, Porsche, and Mazda. In 1997, the first European series based around Le Mans Prototypes was launched, to differ from IMSAS WSC class, the USRRC named their open-cockpit prototypes Can-Am in an attempt to resurrect the sportscar championship of the 1970s. However the USRRC collapsed before the end of 1999, with the series becoming the Rolex Sports Car Series who chose to use the FIAs SR1,1998 saw a great expansion for the ACOs LMP classes. Following the cancellation of the IMSA GT Championship at the end of 1998 and this series used the same class structure as the 24 Hours of Le Mans, meaning it was the first championship to use the LMP name. At the same time, the ACO greatly altered their LMP classes, the smaller LMP2 class were briefly eliminated, while a new class of closed-cockpit prototypes were allowed in, known as LMGTP. These cars were evolutions of production-based road cars that the ACO considered too advanced and too fast to fall under the GT class regulations, in 2000, changes were made to the LMP regulations, as the ACO once again split the open-cockpit LMP class
22.
North American X-15
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The X-15 set speed and altitude records in the 1960s, reaching the edge of outer space and returning with valuable data used in aircraft and spacecraft design. During the X-15 program,13 flights by eight pilots met the Air Force spaceflight criterion by exceeding the altitude of 50 miles, thus qualifying these pilots as being astronauts. The Air Force pilots qualified for astronaut wings immediately, while the pilots were eventually awarded NASA astronaut wings in 2005,35 years after the last X-15 flight. The only Navy pilot in the X-15 program never took the aircraft above the requisite 50 mile altitude and so as a result, of the 199 X-15 missions, two flights qualified as true space flights per the international definition of a spaceflight by exceeding 100 kilometers in altitude. The X-15 was based on a study from Walter Dornberger for the National Advisory Committee for Aeronautics for a hypersonic research aircraft. The requests for proposal were published on 30 December 1954 for the airframe, the X-15 was built by two manufacturers, North American Aviation was contracted for the airframe in November 1955, and Reaction Motors was contracted for building the engines in 1956. Like many X-series aircraft, the X-15 was designed to be carried aloft, Air Force NB-52A, The High and Mighty One, and NB-52B, The Challenger served as carrier planes for all X-15 flights. Release took place at an altitude of about 8.5 miles, the X-15 fuselage was long and cylindrical, with rear fairings that flattened its appearance, and thick, dorsal and ventral wedge-fin stabilizers. Parts of the fuselage were heat-resistant nickel alloy, the retractable landing gear comprised a nose-wheel carriage and two rear skids. The skids did not extend beyond the fin, which required the pilot to jettison the lower fin just before landing. The X-15 was a program and changes were made to various systems over the course of the program. Alternatively, if the engine was not started the pilot went directly to a landing. The main rocket engine operated only for a short part of the flight. Without main engine thrust, the X-15s instruments and control surfaces remained functional, because the X-15 also had to be controlled in an environment where there was too little air for aerodynamic flight control surfaces, it had a reaction control system that used rocket thrusters. There were two different X-15 pilot control setups, one used three joysticks, the other, one joystick, the X-15 type with multiple control sticks for the pilot included a traditional rudder and stick, and another joystick on the left which sent commands to the reaction control system. A third joystick on the side was used during high-G maneuvers to augment the center stick. In addition to input, the X-15 Stability Augmentation System sent inputs to the aerodynamic controls to help the pilot maintain attitude control. The reaction control system could be operated in two modes, manual and automatic, the automatic mode used a feature called Reaction Augmentation System that helped stabilize the vehicle at high altitude
23.
Experimental aircraft
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An experimental aircraft is an aircraft that has not yet been fully proven in flight. Often, this implies that new technologies are being tested on the aircraft. The term experimental aircraft is sometimes used to refer to aircraft flown with an Experimental category airworthiness certificate. In the U. S. this includes most homebuilt aircraft, many of which are based on conventional designs, the term research aircraft, by contrast, generally denotes aircraft modified to perform scientific studies, such as weather research or geophysical surveying. List of experimental aircraft List of X-planes
24.
Dornier Do 335
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The Dornier Do 335 Pfeil was a World War II heavy fighter built by the Dornier company. The two-seater trainer version was also called Ameisenbär, the Pfeils performance was much better than other twin-engine designs due to its unique push-pull layout and the much lower aerodynamic drag of the in-line alignment of the two engines. It was Germanys fastest piston-engined aircraft of World War II, the Luftwaffe was desperate to get the design into operational use, but delays in engine deliveries meant that only a handful were delivered before the war ended. Tandem engines were used on most of the multi-engine Dornier flying boats that followed, including the highly successful Do J Wal and it also keeps the weight of the twin powerplants near, or on, the aircraft centerline, increasing the roll rate compared to a traditional twin. In addition, an engine failure does not lead to asymmetric thrust. In 1939, Dornier was busy working on the P.59 high-speed bomber project, in May 1942, Dornier submitted an updated version with a 1,000 kg bombload as the P.231, in response to a requirement for a single seat, Schnellbomber-like high-speed bomber/intruder. P.231 was selected as the winner after beating rival designs from Arado, Junkers, in autumn 1942, Dornier was told that the Do 335 was no longer required, and instead a multi-role fighter based on the same general layout would be accepted. This delayed the delivery as it was modified for the new role. The use of a nose-mount annular radiator for the forward engine, when fitted with DB 603A engines delivering 1,750 PS at takeoff it had the largest displacement inverted V12 aircraft engine design mass-produced during the Third Reichs existence. However, several problems during the flight of the Do 335 would continue to plague the aircraft through most of its short history. Issues were found with the landing gear and with the maingears wheel well doors. The Do 335 V1 made 27 flights, flown by three different pilots, during these test flights the V2, Stammkennzeichen CP+UB was completed and made its first flight on 31 December 1943, again under the control of Dieterle. New to the V2 were upgraded DB 603A-2 engines, and several refinements learned from the test flights of the V1 as well as further windtunnel testing, on 20 January 1944, the Do 335 V3, Stammkennzeichen CP+UC was completed and flown for its first time by Werner Altrogge. Thus the Do 335 was scheduled to begin construction, with the initial order of 120 preproduction aircraft to be manufactured by DWF to be completed no later than March 1946. This number included a number of bombers, destroyers, and several yet to be developed variants, at the same time, DWM was scheduled to build over 2000 Do 335s in various models, due for delivery in March 1946 as well. On 23 May 1944, Hitler, as part of the developing Jägernotprogramm directive, the main production line was intended to be at Manzell, but a bombing raid in March destroyed the tooling and forced Dornier to set up a new line at Oberpfaffenhofen. However, Ernst Heinkel managed to delay, and eventually ignore, its implementation, at least 16 prototype Do 335s were known to have flown on a number of DB603 engine subtypes including the DB 603A, A-2, G-0, E and E-1. The first preproduction Do 335 starting with W. Nr 240101, approximately 22 preproduction aircraft were thought to have been completed and flown before the end of the war, including approximately 11 A-0s converted to A-11s for training purposes
25.
Heavy fighter
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A heavy fighter is a fighter aircraft designed to carry heavier weapons or operate at longer ranges. To achieve acceptable performance, most heavy fighters were twin-engined, the twin-engine heavy fighter was a major design class during the pre-World War II period, conceived as long-range escort fighters or heavily armed bomber destroyers. Many twin-engined heavy fighters eventually found their niche as night fighters, a major heavy fighter design was the Messerschmitt Bf 110, a German fighter that, prior to the war, the Luftwaffe considered more important than their single-engine fighters. Many of the best pilots were assigned to Bf 110 wings and this doctrine proved to be a costly mistake. In practice the Bf 110 was capable of using this combination of features for only a short time, following the example set by the Bf 110, the Japanese built the broadly similar Kawasaki Ki-45 Toryu. Likewise neutral Netherlands built the twin-boom Fokker G. I, only to be seized by the Luftwaffe after the German invasion of the Netherlands, perhaps in the belief that The bomber will always get through, the British lagged behind in its heavy fighter development. Apart from the Westland Whirlwind and the Welkin, built only in modest numbers, during the Battle of Britain, Bristol Blenheim bombers were fitted, as an interim measure and in utmost secrecy, with radars and ventral gun packs, turning them into the RAFs first night fighters. More successful was the Bristol Beaufighter, which reused major portions of the earlier Beaufort torpedo bomber. Armed with six.303 inch machine guns, four 20 mm cannon and an assortment of bombs and rockets, with the addition of radar, it was one of the Royal Air Forces main night fighters. Similarly, the de Havilland Mosquito fast bomber was later adapted for both day and night fighter use, during the late 1930s, Bell Aircraft of the United States designed the YFM-1 Airacuda bomber destroyer. Very large and heavily armed, the Airacuda was plagued with design flaws, only 13 examples were eventually built, the most successful heavy fighter of the war was the Lockheed P-38 Lightning. It was designed to carry heavy armament at high speed or long range, for a variety of reasons, notably its excellent twin turbochargers and its crew of one, it dramatically outperformed its German and British counterparts. In service it was used as a fighter, following B-17 Flying Fortress raids deep into German-held Europe where it was able to hold its own with the much lighter German fighters. In its escort role, the P-38 was the first Allied fighter over Berlin and it was also highly successful in the Pacific theatre, where its long range proved a pivotal advantage. Expensive to produce and maintain, it was relegated to other roles when the single-engined, but equally long-ranged, P-51D Mustang reached squadrons. It was among the fastest piston-engined aircraft ever built, and heavily armed with four 20mm M2 cannon and four 0.50 inch M2 Browning machine guns, with hard points for bombs or a torpedo. Although Grumman designed and developed the aircraft during World War II and it served in the Korean War and retired in 1954. The last piston-engined heavy fighters to see service were the de Havilland Hornet and its version the Sea Hornet
26.
Airbus A380
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The Airbus A380 is a double-deck, wide-body, four-engine jet airliner manufactured by European manufacturer Airbus. It is the worlds largest passenger airliner, and the airports at which it operates have upgraded facilities to accommodate it and it was initially named Airbus A3XX and designed to challenge Boeings monopoly in the large-aircraft market. The A380 made its first flight on 27 April 2005 and entered service on 25 October 2007 with Singapore Airlines. The A380s upper deck extends along the length of the fuselage. The A380-800 has a range of 8,500 nautical miles, serving the second- and third-longest non-stop scheduled flights in the world. As of February 2017, Airbus had received 317 firm orders and delivered 208 aircraft, mcDonnell Douglas unsuccessfully offered its smaller, double-deck MD-12 concept for sale. Roeder was given approval for further evaluations of the UHCA after a presentation to the President. The megaproject was announced at the 1990 Farnborough Air Show, with the goal of 15% lower operating costs than the 747-400. Airbus organised four teams of designers, one each of its partners to propose new technologies for its future aircraft designs. The designs were presented in 1992 and the most competitive designs were used and this joint study was abandoned two years later, Boeings interest having declined because analysts thought that such a product was unlikely to cover the projected $15 billion development cost. Despite the fact only two airlines had expressed public interest in purchasing such a plane, Airbus was already pursuing its own large-plane project. In June 1994, Airbus announced its plan to develop its own very large airliner, Airbus considered several designs, including an unusual side-by-side combination of two fuselages from its A340, the largest Airbus jet at the time. The A3XX was pitted against the VLCT study and Boeings own New Large Aircraft successor to the 747. From 1997 to 2000, as the East Asian financial crisis darkened the market outlook, Airbus refined its design, the A380 designation was a break from previous Airbus families, which had progressed sequentially from A300 to A340. It was chosen because the number 8 resembles the double-deck cross section, the aircraft configuration was finalised in early 2001, and manufacturing of the first A380 wing-box component started on 23 January 2002. The development cost of the A380 had grown to €11-14 billion when the first aircraft was completed, major structural sections of the A380 are built in France, Germany, Spain, and the United Kingdom. A380 components are provided by suppliers from around the world, the four largest contributors, by value, are Rolls-Royce, Safran, United Technologies, for the surface movement of large A380 structural components, a complex route known as the Itinéraire à Grand Gabarit was developed. The front and rear sections are shipped on one of three RORO ships from Hamburg in northern Germany to the United Kingdom
27.
Iberia (airline)
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Iberia, legally incorporated as Iberia, Líneas Aéreas de España, S. A. Operadora, Sociedad Unipersonal, is the flag carrier airline of Spain founded in 1927. Based in Madrid, it operates a network of services from its main base of Madrid-Barajas Airport. Iberia, with Iberia Regional and with Iberia Express, is a part of Iberia Group, in addition to transporting passengers and freight, Iberia Group carries out related activities, such as aircraft maintenance, handling in airports, IT systems and in-flight catering. Iberia Group airlines fly to over 109 destinations in 39 countries, on 8 April 2010, it was confirmed that British Airways and Iberia had signed an agreement to merge, making the combined operation the third largest commercial airline in the world by revenue. Shareholders of both carriers approved the deal on 29 November 2010, the newly merged company, known as International Airlines Group, was established in January 2011, although both airlines will continue to operate under their current brands. Iberia, Compañía Aérea de Transportes was incorporated on 28 June 1927 with an investment by the financier Horacio Echevarrieta. Flight operations started on 14 December 1927, within a year, the company was sponsored by the Spanish government to provide postal transport between Madrid and Barcelona. During the dictatorship of Miguel Primo de Rivera, the companies in Spain were combined and became state-controlled as a general interest public utility. As a consequence, Iberia was merged into Compañía de Líneas Aéreas Subvencionadas S. A. the name Iberia continued to be registered by Director-General Daniel de Araoz y Aréjula. As the name Iberia was still registered, it was used when operations began in nationalist-held territory towards the end of the Spanish Civil War, following the Civil War, Iberia became a purely domestic airline. At the end of the 1930s, the served the Seville–Larache–Cabo Juby–Las Palmas, Barcelona–Saragosa–Burgos–Salamanca–Seville–Tetuan. The airline was nationalised on 30 September 1944 and became part of Instituto Nacional de Industria, in 1946, Iberia was the first airline to fly between Europe and South America after World War II, using a Douglas DC-4 to operate flights between Madrid and Buenos Aires. By the Pact of Madrid in 1953, visa requirements were eliminated for US visitors to Spain and this stimulated the start of transatlantic flights between Spain and United States the following year. In addition, the made in Montreal to the Convention on International Civil Aviation on 14 June 1954 were liberal to Spain. The airline phased in the first of three Super Constellations in June 1954, the aircraft was named Santa María to commemorate Columbus first voyage. From 1961 Iberia had a fleet of Douglas DC-8 four-engined long range jet airliners, the busiest route was Madrid to Buenos Aires. By 1965 a joint board of Iberia and Aviaco was set up to coordinate policies so that services did not conflict, in the early 1970s the company bought Douglas DC-9s, Boeing 727s, Douglas DC-10s and Boeing 747s as it expanded routes to Central America. In June 1990, the carrier bought 16 Boeing 757s for US$1 billion, including spares and training, in June 1990 the company led a consortium to buy an 85% stake in Aerolíneas Argentinas for an agreed $2billion and the following year bought a 45% stake in Viasa for $145million
28.
Stabilizer (aeronautics)
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An aircraft stabilizer is an aerodynamic surface, typically including one or more movable control surfaces, that provides longitudinal and/or directional stability and control. A stabilizer can feature a fixed or adjustable structure on which any movable control surfaces are hinged, depending on the context, stabilizer may sometimes describe only the front part of the overall surface. In the conventional configuration, separate vertical and horizontal stabilizers form an empennage positioned at the tail of the aircraft. Other arrangements of the empennage, such as the V-tail configuration, feature stabilizers which contribute to a combination of longitudinal and directional stabilization, Longitudinal stability and control may be obtained with other wing configurations, including canard, tandem wing and tailless aircraft. Some types of aircraft are stabilized with electronic control, in this case, fixed. Transonic flight makes special demands on horizontal stabilizers, since the crossing of the barrier is associated with a sudden move aft of the center of lift. Another role of a stabilizer is to provide longitudinal static stability. Stability can be defined only when the vehicle is in trim and this maintains a constant aircraft attitude, with unchanging pitch angle relative to the airstream, without active input from the pilot. The elevator serve to control the pitch axis, in case of a movable tail. In the conventional configuration the horizontal stabilizer is a horizontal tail or tailplane located to the rear of the aircraft. This is the most common configuration, on many aircraft, the tailplane assembly consists of a fixed surface fitted with a hinged aft elevator surface. Trim tabs may be used to pilot input forces, conversely in some cases, such as small aircraft with all-moving stabilizers. Most airliners and transport aircraft feature a large, slow-moving trimmable tail plane which is combined with independently-moving elevators. The elevators are controlled by the pilot or autopilot and primarily serve to change the attitude, while the whole assembly is used to trim. Many supersonic aircraft feature an all-moving tail assembly, also named stabilator, variants on the conventional configuration include the T-tail, Cruciform tail, Twin tail and Twin-boom mounted tail. Three-surface aircraft such as the Piaggio P, lacking elevators, the tailplanes of these aircraft were not what is now called conventional stabilizers. For example, the Voisin was a layout with a foreplane that was neither stabilizing nor mainly lifting, it was called an équilibreur. In the canard configuration, a wing, or foreplane, is located in front of the main wing
29.
T-tail
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A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. The arrangement looks like the capital letter T, hence the name, the T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base of the fin. The tailplane is kept out of the disturbed airflow behind the wing and fuselage. Responsive pitch control is crucial for aircraft flying at low speed and this configuration also allows high performance aerodynamics and an excellent glide ratio as the empennage is less affected by wing and fuselage slipstream. The American McDonnell F-101 Voodoo jet fighter suffered from throughout its service life. The vertical stabilizer must be considerably stronger and stiffer to support the forces generated by the tailplane. The T-tail configuration can cause maintenance concerns, the control runs to the elevators are more complex, and elevator surfaces are much more difficult to casually inspect from the ground. The loss of Alaska Airlines Flight 261 was directly attributed to lax maintenance of the T-tail, in order to mitigate some of these drawbacks, a compromise is also possible. The tailplane can be mounted part way up the fin rather than right at the top, the Sud Aviation Caravelle is an example of an aircraft with this configuration
30.
Bombardier CRJ200
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The Bombardier CRJ100 and CRJ200 are a family of regional airliners manufactured by Bombardier, and based on the Canadair Challenger business jet. These regional jet models were known as the Canadair CRJ100 and CRJ200. The aircraft was based on the Canadair Challenger design, which was purchased by Canadair from Bill Lear in 1976 and that lengthening did not occur, the effort being canceled in 1981, but the idea did not disappear. In 1987, studies began for a more ambitious stretched configuration. The Canadair name was retained despite the fact that Bombardier had bought out the company, the type obtained certification in late 1992, with initial delivery to customers late in that year. The CL-600 design was stretched 5.92 meters to create the CRJ100, with fuselage plugs fore and aft of the wing, typical seating was 50 passengers, the maximum load being 52 passengers. It was followed by the CRJ100 ER subvariant with 20% more range, the CRJ100 SE sub-variant was produced to more closely meet the needs of corporate and executive operators. The CRJ200 is identical to the 100 model except for more efficient engines, Pinnacle Airlines had operated some with 44 seats, designated as CRJ440, with closets in the forward areas of the passenger cabin though these were converted to 50 seat airplanes. S. Similarly, Comairs fleet of 40-seat CRJ200s were sold at a price to discourage Comair from purchasing the less expensive. There is also a CRJ200 freighter version which is designated CRJ200 PF which was developed in cooperation with Cascade Aerospace on the request of West Air Sweden, several models of the CRJ have been produced, ranging in capacity from 40 to 50 passengers. The Regional Jet designations are marketing names and the designation is CL-600-2B19. CRJ100 The CRJ100 is the original 50-seat version and it is equipped with General Electric CF34-3A1 engines. Operators include Air Georgian and RwandAir, among others, CRJ200 The CRJ200 is identical to the CRJ100 except for its engines, which were upgraded to the CF34-3B1 model, offering improved efficiency. CRJ200PF Package freighter version of CRJ200, CRJ440 Certified up to 44-seat, this version was designed with fewer seats in order to meet the needs of some major United States airlines. Challenger 800/850 A business jet variant of the CRJ200 CRJ500 Proposed 50-seat version with wing, since the project was terminated and production stopped, no new CRJ-200/100s have been produced, but over the years maintenance and newer technologies have added to the planes. Some of the larger versions such as the CRJ700 have begun the processes of adding Wi-Fi access on board the aircraft, but no project has begun for the CRJ200/100 to implement Wi-Fi compatibility. U. S. airlines are accelerating retirement of these 50-seat regional jets because rising fuel prices were making them uneconomical to operate, the retirements are also reducing the value of their parts. Airlines are slowly replacing the jet with more modern aircraft like the Embraer E-175, the aircrafts captain was the sole fatality
31.
Fokker 70
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The Fokker 70 is a narrow-body, twin-engined, medium-range, turbofan regional airliner produced by Fokker as a smaller version of the Fokker 100. Both the F70 and F100 were preceded by the first jet airliner manufactured by Fokker, since its first flight in 1993,47 aircraft, plus one prototype, have been manufactured and 38 are still in active service with airlines around the world. The Fokker company of the Netherlands started to develop the airliner in November 1992 with an aim to replace its aging Fokker F28 airliner, with a more modern and fuel efficient aircraft. The Fokker 70s first flight occurred on 4 April 1993, at the base at Woensdrecht in southern Netherlands. Following its first flight, the Fokker 70 was flown to Granada and Spain, the first production aircraft first flew in July 1994. Certification was granted on 14 October 1994, while the first delivery of a Fokker 70 to a customer, Ford Motor Company, the launch customer of this aircraft by an airline was the now-defunct Indonesian airline, Sempati Air. The development of the Fokker 70 was based on the requirements of airlines, for which the Fokker 50 or ATR42 were too small. The development consisted in cutting various sections of the fuselage of the Fokker 100, removing 4.62 metres of the total length but keeping the wings. With these specifications, total capacity is 80 passengers,70 in the U. S. due more to meet scope clause requirements than any Federal Aviation Administration certification. The Fokker 70 is powered by two Rolls-Royce Tay 620 turbofans placed at the back of the fuselage, with 61.6 kN of thrust, the weight varies from 22,673 kilograms when empty to 41,730 kilograms at maximum takeoff weight. An airbrake on the 70s tail section – similar to found on the BAe 146 – allows it to conform with the 5. 5° glide slope at London City Airport. Its avionics suite is similar to the Fokker 100, Fokkers March 1996 bankruptcy ended any hopes of further production for the U. S. The last Fokker 70 was delivered in April 1997, when the line closed following Fokkers bankruptcy the previous year. Over the 70s short production life,47 were built, the aircraft had been operating Flight 111 from Vienna to Munich with 28 passengers and four crew on board, when its engines failed during landing descent due to icing. The aircraft was damaged, however only three passengers suffered minor injuries
32.
Boeing 727
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The Boeing 727 is a midsized, narrow-body three-engined jet aircraft built by Boeing Commercial Airplanes from the early 1960s to 1984. It can carry 149 to 189 passengers and later models can fly up to 2,700 nautical miles nonstop, intended for short and medium-length flights, the 727 can use relatively short runways at smaller airports. It has three Pratt & Whitney JT8D engines below the T-tail, one on side of the rear fuselage with a center engine that connects through an S-duct to an inlet at the base of the fin. The 727 is Boeings only trijet aircraft, the 727 followed the 707, a quad-jet airliner, with which it shares its upper fuselage cross-section and cockpit design. The 727-100 first flew in February 1963 and entered service with Eastern Air Lines in February 1964, the 727 became a mainstay of airlines domestic route networks and was also used on short- and medium-range international routes. Passenger, freighter, and convertible versions of the 727 were built, the 727 was heavily produced into the 1970s, the last 727 was completed in 1984. As of July 2016, a total of 64 Boeing 727s were in service with 26 airlines, plus a few more in government. Airport noise regulations have led to 727s being equipped with hush kits, United Airlines requested a four-engine aircraft for its flights to high-altitude airports, especially its hub at Stapleton International Airport in Denver, Colorado. American Airlines, which was operating the four-engined Boeing 707 and Boeing 720, eventually, the three airlines agreed on a trijet design for the new aircraft. In 1959, Lord Douglas, chairman of British European Airways, suggested that Boeing and de Havilland Aircraft Company work together on their trijet designs, the two designs had a similar layout, the 727 being slightly larger. At that time Boeing intended to use three Allison AR963 turbofan engines, license-built versions of the Rolls-Royce RB163 Spey used by the Trident, Boeing and de Havilland each sent engineers to the other companys locations to evaluate each others designs, but Boeing eventually decided against the joint venture. Once Pratt & Whitney agreed to go ahead with development of the JT8D, Eddie Rickenbacker, chairman of the board of Eastern, told Boeing that the airline preferred the JT8D for its 727s. Boeing had not offered the JT8D, as it was about 1,000 lb heavier than the RB163, though more powerful. Boeing reluctantly agreed to offer the JT8D as an option on the 727, with high-lift devices on its wing, the 727 could use shorter runways than most earlier jets. The airliners middle engine at the rear of the fuselage gets air from an inlet ahead of the vertical fin through an S-shaped duct. This S-duct proved to be troublesome in that flow distortion in the duct induced a surge in the engine on the take-off of the first flight of the 727-100. This was fixed by the addition of several large vortex generators in the inside of the first bend of the duct, the 727 was designed for smaller airports, so independence from ground facilities was an important requirement. This led to one of the 727s most distinctive features, the built-in airstair that opens from the underbelly of the fuselage
33.
Vickers VC10
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The Vickers VC10 is a long-range British airliner designed and built by Vickers-Armstrongs Ltd and first flown at Brooklands, Surrey, in 1962. The airliner was designed to operate on routes from the shorter runways of the era and commanded excellent hot. Although only a small number of VC10s were built, they provided long service with BOAC. They were also used from 1965 as strategic air transports for the Royal Air Force, the type was retired from RAF service on 20 September 2013. It has been succeeded in the aerial refuelling role by the Airbus Voyager, vC10K3 ZA147 performed the final flight of the type on 25 September 2013. Although privately owned, Britains aviation industry had been government-managed in practice, during the 1950s, the government required the aviation industry to consolidate, in consequence only two engine makers were left by 1959, Rolls-Royce and Bristol Siddeley. In 1951, the Ministry of Supply asked Vickers-Armstrongs to consider a military development of the Valiant V bomber with trans-Atlantic range as a successor to the de Havilland Comet. The concept interested BOAC, who entered into discussion with Vickers, in October 1952, Vickers were contracted to build a prototype which they designated the Type 1000, followed in June 1954 by a production order for six aircraft for the RAF. The planned civil airliner was known as the VC7, development was prolonged by the need to meet the RAFs requirements for short take-off and a self-loading capability. Work started on the prototype but by 1955 the aircrafts increased weight required a powerful engine. In 1955, the government cancelled the RAF order in a round of defence cuts, though BOAC had ordered modified Comet 4s, it viewed the type as an intermediate rather than a long term type. In 1956, BOAC ordered 15 Boeing 707s, several companies proposed a suitable replacement. De Havilland offered the DH.118, a development of the Comet 5 project while Handley Page proposed the HP.97, based on their V bomber, after carefully considering the routes, Vickers offered the VC10. Crucially, Vickers was the only firm willing to launch its design as a private venture, the VC10 was a new design but used some production ideas and techniques, as well as the Conway engines, developed for the V.1000 and VC7. The onboard avionics and flight-deck technology was advanced, a quadruplicated automatic flight control system was intended to enable fully automatic zero-visibility landings. Capacity was up to 135 passengers in a two-class configuration, Vickers calculated that it would need to sell 80 VC10s at about £1.75 million each to break even so, apart from BOACs 25, another 55 remained to be sold. Vickers offered a version, the VC11, to BEA for routes like those to Athens and Beirut. Vickers revamped its plans to try to achieve break-even point with 35 sales at £1.5 million each
34.
Douglas DC-9
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The McDonnell Douglas DC-9 is a twin-engine, single-aisle jet airliner. It was first manufactured in 1965 with its maiden flight later that year, the DC-9 was designed for frequent, short flights. The final DC-9 was delivered in October 1982, the DC-9-based airliners, MD-80, MD-90 and Boeing 717 later followed in production. With the final deliveries of the 717 in 2006, production of the DC-9/MD-80/90/717 aircraft family ceased after 41 years, during the 1950s Douglas Aircraft studied a short- to medium-range airliner to complement their higher capacity, long range DC-8. A medium-range four-engine Model 2067 was studied but it did not receive enough interest from airlines, in 1960, Douglas signed a two-year contract with Sud Aviation for technical cooperation. Douglas would market and support the Sud Aviation Caravelle and produce a licensed version if airlines ordered large numbers, none were ordered and Douglas returned to its design studies after the cooperation deal expired. In 1962, design studies were underway, the first version seated 63 passengers and had a gross weight of 69,000 lb. This design was changed into what would be initial DC-9 variant, Douglas gave approval to produce the DC-9 on April 8,1963. Unlike the competing but larger Boeing 727 trijet, which used as many 707 components as possible, the DC-9 has two rear-mounted Pratt & Whitney JT8D turbofan engines, relatively small, efficient wings, and a T-tail. The DC-9s takeoff weight was limited to 80,000 lb for a flight crew by Federal Aviation Agency regulations at the time. DC-9 aircraft have five seats across for economy seating, the airplane seats 80 to 135 passengers depending on version and seating arrangement. Accessibility and short field characteristics were called for, turnarounds were simplified by built-in airstairs, including one in the tail, which shortened boarding and deplaning times. The tail-mounted engine design facilitated a clean wing without engine pods, for example, flaps could be longer, unimpeded by pods on the leading edge and engine blast concerns on the trailing edge. This simplified design improved airflow at low speeds and enabled lower takeoff and approach speeds, thus lowering field length requirements, the second advantage of the tail-mounted engines was the reduction in foreign object damage from ingested debris from runways and aprons. With this position, the engines could ingest ice streaming off the wing roots, third, the absence of engines in underslung pods allowed a reduction in ground clearance, making the aircraft more accessible to baggage handlers and passengers. The first DC-9, a model, flew on February 25,1965. The second DC-9 flew a few later, with a test fleet of five aircraft flying by July. This allowed the initial Series 10 to gain airworthiness certification on November 23,1965, the initial Series 10 would be followed by the improved -20, -30, and -40 variants
35.
Glider (sailplane)
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A sailplane or glider is a type of glider aircraft used in the sport of gliding. Sailplanes are aerodynamically streamlined and are capable of soaring in rising air, sailplanes benefit from producing the least drag for any given amount of lift, and this is best achieved with long, thin wings, a fully faired narrow cockpit and a slender fuselage. Aircraft with these features are able to climb efficiently in rising air produced by thermals or hills, sailplanes can glide long distances at high speed with a minimum loss of height in between. Gliders have rigid wings and either skids or undercarriage, in contrast hang gliders and paragliders use the pilots feet for the start of the launch and for the landing. These latter types are described in articles, though their differences from sailplanes are covered below. Gliders are usually launched by winch or aerotow, though other methods, auto tow, all sailplanes soar, but some gliders do not soar and are simply engineless aircraft towed by another aircraft to a desired destination and then cast off for landing. Military gliders are only, and are abandoned after landing, having served their purpose. Motor gliders are gliders with engines which can be used for extending a flight and even, in some cases, Some high-performance motor gliders may have an engine-driven retractable propeller which can be used to sustain flight. Other motor gliders have enough thrust to launch themselves before the engine is retracted and are known as self-launching gliders, another type is the self-launching touring motor glider, where the pilot can switch the engine on and off in flight without retracting their propellers. Sir George Cayleys gliders achieved brief wing-borne hops from around 1849, in the 1890s Otto Lilienthal built gliders using weight shift for control. In the early 1900s the Wright Brothers built gliders using movable surfaces for control, in 1903 they successfully added an engine. After World War I gliders were built for sporting purposes in Germany, the sporting use of gliders rapidly evolved in the 1930s and is now their main application. As their performance improved, gliders began to be used for cross-country flying, in 1930, pilot Frank Hawks flew the Texaco Eaglet with tow plane from San Diego to New York over eight days, helping to popularize the activity in the United States. Early gliders had no cockpit and the pilot sat on a seat located just ahead of the wing. These were known as gliders and they were usually launched from the tops of hills. To enable gliders to soar more effectively than primary gliders, the designs minimized drag, gliders now have very smooth, narrow fuselages and very long, narrow wings with a high aspect ratio and winglets. The early gliders were mainly of wood with metal fastenings, stays. Later fuselages made of fabric-covered steel tube were married to wood and fabric wings for lightness, New materials such as carbon-fiber, fiber glass and Kevlar have since been used with computer-aided design to increase performance
36.
Stall (fluid mechanics)
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In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the angle of attack of the foil is exceeded. The critical angle of attack is typically about 15 degrees, but it may vary depending on the fluid, foil. Stalls in fixed-wing flight are often experienced as a reduction in lift as the pilot increases the wings angle of attack. A stall does not mean that the engine have stopped working, vectored thrust in manned and unmanned aircraft is used to surpass the stall limit, thereby giving rise to post-stall technology. Because stalls are most commonly discussed in connection with aviation, this article discusses stalls as they relate mainly to aircraft, the principles of stall discussed here translate to foils in other fluids as well. A stall is a condition in aerodynamics and aviation wherein the angle of attack increases beyond a point such that lift begins to decrease. The angle at which this occurs is called the angle of attack. The critical angle of attack is the angle of attack on the lift coefficient versus angle-of-attack curve at which the lift coefficient occurs. Flow separation begins to occur at angles of attack while attached flow over the wing is still dominant. As angle of attack increases, the regions on the top of the wing increase in size. At the critical angle of attack, separated flow is so dominant that additional increases in angle of attack produce less lift, a fixed-wing aircraft during a stall may experience buffeting or a change in attitude. Most aircraft are designed to have a stall with characteristics that will warn the pilot. For example, an aircraft that does not buffet before the stall may have an alarm or a stick shaker installed to simulate the feel of a buffet by vibrating the stick fore. The buffet margin is, for a set of conditions, the amount of ‘g’. The critical angle of attack in steady straight and level flight can be attained only at low airspeed, attempts to increase the angle of attack at higher airspeeds can cause a high-speed stall or may merely cause the aircraft to climb. Any yaw of the aircraft as it enters the stall regime can result in autorotation, as air no longer flows smoothly over the wings during a stall, aileron control of roll becomes less effective, whilst simultaneously the tendency for the ailerons to generate adverse yaw increases. This characteristic increases the lift from the wing and increases the likelihood of the aircraft entering into a spin
37.
Consolidated PBY Catalina
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The Consolidated PBY Catalina, also known as the Canso in Canadian service, was an American flying boat, and later an amphibious aircraft of the 1930s and 1940s produced by Consolidated Aircraft. It was one of the most widely used seaplanes of World War II, Catalinas served with every branch of the United States Armed Forces and in the air forces and navies of many other nations. During World War II, PBYs were used in warfare, patrol bombing, convoy escorts, search and rescue missions. The PBY was the most numerous aircraft of its kind and the last active military PBYs were not retired from service until the 1980s. In 2014, nearly 80 years after its first flight, the continues to fly as a waterbomber in aerial firefighting operations all over the world. In accordance with contemporary British naming practice of naming seaplanes after coastal towns, Royal Canadian Air Force examples were named Canso. The Royal Air Force used the name Catalina and the US Navy adopted this name in 1942, the United States Army Air Forces and later the United States Air Force used the designation OA-10. US Navy Catalinas used in the Pacific against the Japanese for night operations were painted black overall, and as a result were sometimes referred to locally as Black Cats. The PBY was originally designed to be a bomber, an aircraft with a long operational range intended to locate. Flying boats had the advantage of not requiring runways, in effect having the entire ocean available, several different flying boats were adopted by the Navy, but the PBY was the most widely used and produced. Although slow and ungainly, Catalinas distinguished themselves in World War II, Allied forces used them successfully in a wide variety of roles for which the aircraft was never intended. They are remembered for their role, in which they saved the lives of thousands of aircrew downed over water. Catalina airmen called their aircraft the Cat on combat missions and Dumbo in air-sea rescue service, Naval doctrine of the 1930s and 1940s used flying boats in a wide variety of roles that today are handled by multiple special-purpose aircraft. The U. S. Navy had adopted the Consolidated P2Y and Martin P3M models for this role in 1931, Consolidated and Douglas both delivered single prototypes of their new designs, the XP3Y-1 and XP3D-1, respectively. Although the Douglas aircraft was a design, the Navy opted for Consolidateds because the projected cost was only $90,000 per aircraft. Consolidateds XP3Y-1 design had a wing with external bracing struts. Wingtip stabilizing floats were retractable in flight to form streamlined wingtips and had licensed from the Saunders-Roe company. The two-step hull design was similar to that of the P2Y, cleaner aerodynamics gave the Model 28 better performance than earlier designs
38.
Twin tail
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A twin tail is a specific type of vertical stabilizer arrangement found on the empennage of some aircraft. Two vertical stabilizers—often smaller on their own than a conventional tail would be—are mounted at the outside of the aircrafts horizontal stabilizer. Separating the control surfaces allows for additional rudder area or vertical surface without requiring a single tail. On multi-engine propeller designs twin fin and rudders operating in the propeller slipstream give greater rudder authority and improved control at low airspeeds, a twin tail can also simplify hangar requirements, give dorsal gunners enhanced firing area, and in some cases reduce the aircrafts weight. It also affords a degree of one tail is damaged. Many canard aircraft designs incorporate twin tails on the tips of the main wing, very occasionally, three or more tails are used, as on the Breguet Deux-Ponts, Lockheed Constellation and Boeing 314 Clipper. A very unusual design can be seen on the E-2 Hawkeye and this arrangement was chosen for the stringent size limitations of carrier-based aircraft. Significant aircraft with twin tails include the Consolidated B-24 Liberator, Handley-Page Halifax, Avro Lancaster, the arrangement is not limited to World War II-vintage aircraft, however. Airbus has filed a patent for a new, twin-tail, trijet design, cruciform tail Pelikan tail T-tail V-tail
39.
Chrislea Super Ace
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The Chrislea Super Ace is a 1940s British four-seat light aircraft built by Chrislea Aircraft Limited. The Super Ace was developed from the earlier Chrislea C. H.3 Series 1 Ace, the Ace had an unusual steering wheel control arrangement which eliminated the conventional rudder bar. The wheel was mounted on a joint, turning it applied aileron, moving it vertically applied elevator. It originally flew with a vertical tail but was soon modified with twin fins. The lone C. H.3 Series 1 Ace first flew in September 1946, soon after the company moved to Exeter, the first production aircraft, the C. H.3 Series 2 Super Ace flew in February 1948. This model was powered by a de Havilland Gipsy Major 10 inline piston engine, Wing and tailplane were now metal structures, the span was increased by 2 ft compared with the Ace, and the fins were smaller and rounder. The control system of the first Super Ace was not well received and, as a result, construction was initiated on a production run of 32 aircraft, but only 18 Super Aces were completed and flown. Only 3 of these stayed in the UK, the rest were either immediately exported, exported after time in the UK or worked abroad under British registration in the Near East, Super Aces flew in Europe, Africa, Asia, South America and Australasia. The final variant, taken from the Super Ace production run, was the C. H.3 Series 4 Skyjeep, the Skyjeep had a tailwheel landing gear, a conventional control stick instead of the wheel and removable top decking on the rear fuselage. A fuselage stretch of 8.5 in improved the legroom and, combined with the rear fuselage. It was powered by a 155 hp Blackburn Cirrus Major 3 engine, in all, three Skyjeeps were built and sold in Uruguay, Indochina and Australia. The Australian machine flew there with a 200 hp de Havilland Gipsy Six engine for a time, sales of the two types were disappointing and 11 of the 32 planned were either not completed or built but not flown. These were scrapped in 1952 when the assets were bought by C. E. Harper Aircraft Limited. There are two flying Super Aces in the UK, G-AKVF and G-AKUW, plus a Skyjeep, C. H.3 Series 1 Ace - four-seat high-wing monoplane with tricycle undercarriage powered by a 125 hp Lycoming O-290 engine, one built. C. H.3 Series 2 Super Ace-145 hp de Havilland Gipsy Major 10 powered, C. H.3 Series 4 Skyjeep - conventional controls and tailwheel,155 hp Blackburn Cirrus Major 3 powered. Data from Jackson 1974 General characteristics Crew, one Capacity, four passengers Length,21 ft 6 in Wingspan,36 ft 0 in Height,7 ft 7½ in Wing area,177 ft² Empty weight,1,350 lb Max. British Civil Aircraft since 1919 Volume 2
40.
Beechcraft Model 18
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The Beechcraft Model 18 is a 6- to 11-seat, twin-engined, low-wing, tailwheel light aircraft manufactured by the Beech Aircraft Corporation of Wichita, Kansas. Continuously produced from 1937 to November 1969, over 9,000 were produced, sold worldwide as a civilian executive, utility, cargo aircraft, and passenger airliner on tailwheels, nosewheels, skis or floats, it was also used as a military aircraft. In World War II, over 90% of USAAF bombardiers and navigators trained in these aircraft, in the early postwar era, the Beech 18 was the pre-eminent business aircraft and feeder airliner. Many are now owned, around the world, with over 300 in the U. S. still on the FAA Aircraft Registry in December 2014. The design was conventional for the time, including twin radial engines, all-metal semimonocoque construction with fabric-covered control surfaces. Less conventional was the twin-tailfin configuration, the Model 18 can be mistaken for the larger Lockheed Electra series of airliners which closely resemble it. Early production aircraft were powered either by two 330-hp Jacobs L-6s or 350-hp Wright R-760Es, the 450-hp Pratt & Whitney R-985 became the definitive engine from the prewar C18S onwards. The Beech 18 prototype first flew on January 15,1937, prior to the Pearl Harbor attack, the Beech 18 was outsold by the Lockheed 12 by two-to-one. However, war priorities forced Lockheed to concentrate on its heavier aircraft, the aircraft has used a variety of engines and has had a number of airframe modifications to increase gross weight and speed. At least one aircraft was modified to a 600-hp Pratt & Whitney R-1340 powerplant configuration, nearly every airframe component has been modified. In 1955, deliveries of the Model E18S commenced, the E18S featured a fuselage that was extended 6 in higher for more headroom in the passenger cabin, all later Beech 18s featured this taller fuselage, and some earlier models have been modified to this larger fuselage. The Model H18, introduced in 1963, featured optional tricycle undercarriage, unusually, the undercarriage was developed for earlier-model aircraft under an STC by Volpar, and installed in H18s at the factory during manufacture. A total of 109 H18s were built with tricycle undercarriage, construction of the Beechcraft Model 18 ended in 1970 with a final Model H18 going to Japan Airlines. Through the years,32 variations of the design had flown, over 200 improvement modification kits were developed. In one case, the aircraft was modified to a tail, trigear, humpbacked configuration. Another distinctive conversion was carried out by PacAero as the Tradewind and this featured a lengthened nose to accommodate the tricycle nosewheel, and the Model 18s twin tailfins were replaced by a single fin. Work began in earnest on a variant specifically for training pilots, bombardiers. The effort resulted in the Army AT-7 and Navy SNB, further development led to the AT-11 and SNB-2 navigation trainers and the C-45 military transport
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Military aircraft
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A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat, Combat aircraft are designed to destroy enemy equipment using their own aircraft ordnance, Combat aircraft are normally developed and procured only by military forces. Non-combat aircraft are not designed for combat as their primary function and these mainly operate in support roles, and may be developed by either military forces or civilian organizations. In 1783, when the first practical aircraft were established, they were adopted for military duties. The main role of fighters is destroying enemy aircraft in air-to-air combat, many are fast and highly maneuverable. Escorting bombers or other aircraft is also a common task and they are capable of carrying a variety of weapons, including machine guns, cannons, rockets and guided missiles. Many modern fighters can attack enemy fighters from a great distance, examples of air superiority fighters include the F-22 Raptor. World War II fighters include the British Spitfire, the American P-51 Mustang, an example of an interceptor would be the MiG-25. An example of a fighter is the Messerschmitt Bf 110. The term fighter is also applied to aircraft that have little air-to-air combat capability – for example the A-10 ground-attack aircraft is operated by USAF Fighter squadrons. Bombers are normally larger, heavier, and less maneuverable than fighter aircraft and they are capable of carrying large payloads of bombs, torpedoes or cruise missiles. Bombers are used almost exclusively for ground attacks and not fast or agile enough to take on enemy fighters head-to-head, a few have a single engine and require one pilot to operate and others have two or more engines and require crews of two or more. A limited number of bombers, such as the B-2 Spirit, have stealth capabilities that keep them from being detected by enemy radar, an example of a conventional modern bomber would be the B-52 Stratofortress. An example of a World War II bomber would be a B-17 Flying Fortress, bombers include light bombers, medium bombers, heavy bombers, dive bombers, and torpedo bombers. The U. S. Navy and Marines have traditionally referred to their light, attack aircraft can be used to provide support for friendly ground troops. Some are able to carry conventional or nuclear weapons far behind enemy lines to strike priority ground targets, attack helicopters attack enemy armor and provide close air support for ground troops. An example historical ground-attack aircraft is the Soviet Ilyushin Il-2 Shturmovik, several types of transport airplanes have been armed with sideways firing weapons as gunships for ground attack. These include the AC-47 and AC-130 aircraft, in modern air forces the distinction between bombers, fighter-bombers, and attack aircraft has become blurred
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Grumman F-14 Tomcat
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The Grumman F-14 Tomcat is an American supersonic, twin-engine, two-seat, variable-sweep wing fighter aircraft. The Tomcat was developed for the United States Navys Naval Fighter Experimental program after the collapse of the F-111B project, the F-14 was the first of the American teen-series fighters, which were designed incorporating air combat experience against MiG fighters during the Vietnam War. The F-14 first flew in December 1970 and made its first deployment in 1974 with the U. S. Navy aboard USS Enterprise, replacing the McDonnell Douglas F-4 Phantom II. The F-14 served as the U. S. Navys primary maritime air superiority fighter, fleet defense interceptor, the Low Altitude Navigation and Targeting Infrared for Night pod system were added in the 1990s and the Tomcat began performing precision ground-attack missions. In the 1980s F-14s were used as land-based interceptors by the Islamic Republic of Iran Air Force during the Iran–Iraq War, where they saw combat against Iraqi warplanes. Iranian F-14s reportedly shot down at least 160 Iraqi aircraft during the war, while only 12 to 16 Tomcats were lost, the Tomcat was retired from the U. S. Navys active fleet on 22 September 2006, having been supplanted by the Boeing F/A-18E/F Super Hornet. The F-14 remains in service with the Islamic Republic of Iran Air Force, the U. S. Navy needed a Fleet Air Defense aircraft with a more powerful radar and longer range missiles than the F-4 Phantom II carried to intercept both enemy bombers and missiles. The Navy was directed to participate in the Tactical Fighter Experimental program with the U. S. Air Force by Secretary of Defense Robert McNamara. The Navy strenuously opposed the TFX as it feared compromises necessary for the Air Forces need for an attack aircraft would adversely impact the aircrafts performance as a fighter. Weight and performance issues plagued the U. S. Navy F-111B variant for TFX, the F-111 manufacturer General Dynamics partnered with Grumman on the Navy F-111B. With the F-111B program in distress, Grumman began studying improvements, in 1966, the Navy awarded Grumman a contract to begin studying advanced fighter designs. Grumman narrowed down these designs to its 303 design, the Navy studied the need for VFAX, an additional fighter that was agiler than the F-4 Phantom for air-combat and ground-attack roles. Grumman continued work on its 303 design and offered it to the Navy in 1967, the company continued to refine the design into 1968. In July 1968, the Naval Air Systems Command issued a request for proposals for the Naval Fighter Experimental program, VFX called for a tandem two-seat, twin-engined air-to-air fighter with a maximum speed of Mach 2.2. It would also have a built-in M61 Vulcan cannon and a close air support role. The VFXs air-to-air missiles would be either six AIM-54 Phoenix or a combination of six AIM-7 Sparrow, bids were received from General Dynamics, Grumman, Ling-Temco-Vought, McDonnell Douglas and North American Rockwell, four bids incorporated variable-geometry wings. McDonnell Douglas and Grumman were selected as finalists in December 1968, Grumman was selected for the contract award in January 1969. Upon winning the contract for the F-14, Grumman greatly expanded its Calverton, Long Island, much of the testing, including the first of many compressor stalls and multiple ejections, took place over Long Island Sound
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McDonnell Douglas F-15 Eagle
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The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather tactical fighter aircraft designed by McDonnell Douglas to gain and maintain air supremacy in aerial combat. Following reviews of proposals, the United States Air Force selected McDonnell Douglas design in 1967 to meet the services need for an air superiority fighter. The Eagle first flew in July 1972, and entered service in 1976 and it is among the most successful modern fighters, with over 100 victories and no losses in aerial combat, with the majority of the kills scored by the Israel Air Force. The Eagle has been exported to Israel, Japan, and Saudi Arabia, the F-15 was originally envisioned as a pure air superiority aircraft. Its design included a secondary ground-attack capability that was largely unused, the aircraft design proved flexible enough that an all-weather strike derivative, the F-15E Strike Eagle, was later developed and entered service in 1989. The F-15 Eagle is expected to be in service with the U. S. Air Force past 2025, newer models are still being produced for foreign users. The F-15 production line is set to end in 2019,47 years after the types first flight. The F-15 can ultimately trace its origins to the Vietnam War, when the U. S. Air Force, at the time, Defense Secretary Robert McNamara was pressing for both services to use as many common aircraft as possible, even if there were performance sacrifices involved. The former were capable in the tactical role, while the latter might be less so. If the Air Force did choose a design, maintaining air superiority would be a top priority. The next month, a report on light tactical aircraft suggested the Air Force purchase the F-5 or A-7 and this point was reinforced after the loss of two Republic F-105 Thunderchief aircraft to obsolete MiG-15s or MiG-17s on 4 April 1965. In April 1965, Harold Brown, at that time director of the DDR&E, stated the position was to consider the F-5. On 1 August, Gabriel Disosway took command of Tactical Air Command and reiterated calls for the F-X, an official requirements document was finalized in October, and sent out as a request for proposals to 13 companies on 8 December 1965. Following a downselect, four companies were asked to further developments. In total, they developed some 500 design concepts, typical designs featured variable-sweep wings, weighed over 60,000 pounds, included a top speed of Mach 2.7 and a thrust-to-weight ratio of 0.75. When the proposals were studied in July 1966, the aircraft were roughly the size and weight of the TFX, and like that aircraft, through this period, studies of combat over Vietnam were producing worrying results. Previous doctrine had stressed long-range combat using missiles, and optimized aircraft for this role, the result was highly loaded aircraft with large radars and excellent speed, but limited maneuverability and often lacking a gun. In early 1967, they proposed that the design had a thrust-to-weight ratio of near 1,1, a maximum speed further reduced to Mach 2.3, a weight of 40,000 pounds
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McDonnell Douglas F/A-18 Hornet
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The McDonnell Douglas F/A-18 Hornet is a twin-engine supersonic, all-weather carrier-capable multirole combat jet, designed as both a fighter and attack aircraft. Designed by McDonnell Douglas and Northrop, the F/A-18 was derived from the latters YF-17 in the 1970s for use by the United States Navy and Marine Corps. The Hornet is also used by the air forces of other nations and, since 1986, by the U. S. Navys Flight Demonstration Squadron. The F/A-18 has a top speed of Mach 1.8 and it can carry a wide variety of bombs and missiles, including air-to-air and air-to-ground, supplemented by the 20-mm M61 Vulcan cannon. It is powered by two General Electric F404 turbofan engines, which give the aircraft a high thrust-to-weight ratio, the F/A-18 has excellent aerodynamic characteristics, primarily attributed to its leading edge extensions. The fighters primary missions are fighter escort, fleet air defense, Suppression of Enemy Air Defenses, air interdiction, close air support, the Hornet first saw combat action during the 1986 United States bombing of Libya and subsequently participated in the 1991 Gulf War and 2003 Iraq War. The F/A-18 Hornet provided the design for the Boeing F/A-18E/F Super Hornet, its larger. In August 1973, Congress mandated that the Navy pursue a lower-cost alternative to the F-14, grumman proposed a stripped F-14 designated the F-14X, while McDonnell Douglas proposed a naval variant of the F-15, but both were nearly as expensive as the F-14. That summer, Secretary of Defense Schlesinger ordered the Navy to evaluate the competitors in the Air Forces Lightweight Fighter program, the Air Force competition specified a day fighter with no strike capability. On 2 May 1975, the Navy announced its selection of the YF-17, since the LWF did not share the design requirements of the VFAX, the Navy asked McDonnell Douglas and Northrop to develop a new aircraft from the design and principles of the YF-17. On 1 March 1977, Secretary of the Navy W. Graham Claytor announced that the F-18 would be named Hornet. Northrop had partnered with McDonnell Douglas as a contractor on NACF to capitalize on the latters experience in building carrier aircraft. On the F-18, the two agreed to evenly split component manufacturing, with McDonnell Douglas conducting final assembly. McDonnell Douglas would build the wings, stabilators, and forward fuselage, while Northrop would build the center and aft fuselage and vertical stabilizers. McDonnell Douglas was the contractor for the naval versions. The F-18, initially known as McDonnell Douglas Model 267, was modified from the YF-17. For carrier operations, the airframe, undercarriage, and tailhook were strengthened, folding wings and catapult attachments were added, and the landing gear widened. To meet Navy range and reserves requirements, McDonnell increased fuel capacity by 4,460 pounds, by enlarging the dorsal spine, a snag was added to the wings leading edge and stabilators to prevent an Aeroelastic flutter discovered in the F-15 stabilator
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Lockheed Martin F-22 Raptor
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The Lockheed Martin F-22 Raptor is a fifth-generation, single-seat, twin-engine, all-weather stealth tactical fighter aircraft developed for the United States Air Force. The aircraft was variously designated F-22 and F/A-22 before it entered service in December 2005 as the F-22A. The Raptors combination of stealth, aerodynamic performance, and situational awareness gives the aircraft unprecedented air combat capabilities, a final procurement tally of 187 operational production aircraft was established in 2009, and the last F-22 was delivered to the USAF in 2012. In 1981 the U. S. Air Force developed a requirement for an Advanced Tactical Fighter as a new air superiority fighter to replace the F-15 Eagle and F-16 Fighting Falcon. Code named Senior Sky, this program was influenced by the emerging threats, including development and proliferation of Soviet Su-27 Flanker-. Each design team produced two prototype air vehicles, one for each of the two engine options, the Lockheed-led team employed thrust vectoring nozzles on YF-22 for enhanced maneuverability in dogfights. The ATFs increasing weight and cost drove out certain requirements during development, side-looking radars were deleted, and the dedicated infra-red search and track system was downgraded from multi-color to single color and then deleted as well. However, space and cooling provisions were retained to allow for future addition of these components, the ejection seat requirement was downgraded from a fresh design to the existing McDonnell Douglas ACES II. After the flight test demonstration and validation of the prototypes, on 23 April 1991, the YF-23 design was considered stealthier and faster, while the YF-22 was more maneuverable. The aviation press speculated that the YF-22 was also adaptable to the U. S. Navys Navalized Advanced Tactical Fighter, but by 1992. F-22 production was split up over many subcontractors across 46 states to increase Congressional support, though this production split may have contributed to increased costs, many capabilities were deferred to post-service upgrades, reducing the initial cost but increasing total program cost. Production supported over 1,000 subcontractors and suppliers and up to 95,000 jobs, the F-22 had several design changes from the YF-22. The swept-back angle of the edge was decreased from 48° to 42°, while the vertical stabilizers were shifted rearward. To improve pilot visibility, the canopy was moved forward 7 inches, the shapes of the wing and stabilator trailing edges were refined to improve aerodynamics, strength, and stealth characteristics. Increasing weight during development caused slight reductions in range and aerodynamic performance, the first F-22, an engineering and manufacturing development aircraft named Raptor 4001, was unveiled at Marietta, Georgia, on 9 April 1997, and first flew on 7 September 1997. In 2006, the Raptors development team, composed of over 1,000 contractors, the F-22 was in production for 15 years, at a rate of roughly two per month during peak production. The USAF originally envisioned ordering 750 ATFs at a cost of $26.2 billion, the 1990 Major Aircraft Review led by Secretary of Defense Dick Cheney reduced this to 648 aircraft beginning in 1996. By 1997, funding instability had further cut the total to 339, in 2004, the Department of Defense further reduced this to 183 operational aircraft, despite the USAFs preference for 381
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Lockheed Martin F-35 Lightning II
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The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, all-weather stealth multirole fighters. The fifth-generation combat aircraft is designed to perform ground attack and air defense missions, on 31 July 2015, the United States Marines declared ready for deployment the first squadron of F-35B fighters after intensive testing. On 2 August 2016, the U. S. Air Force declared its first squadron of F-35A fighters combat-ready, the F-35 descends from the X-35, the winning design of the Joint Strike Fighter program. An aerospace industry led by Lockheed Martin designed and manufactures it. Other major F-35 industry partners include Northrop Grumman, Pratt & Whitney, the F-35 first flew on 15 December 2006. The United States plans to buy 2,457 aircraft and its variants are to provide the bulk of the crewed tactical airpower of the U. S. Air Force, Navy and the Marine Corps over the coming decades. Deliveries of the F-35 for the U. S. military are scheduled until 2037 with a service life up to 2070. The United States principally funds the F-35 JSF development, with funding from partners. The partner nations are either NATO members or close U. S. allies, the program is the most expensive military weapons system in history, and has been much criticized inside and outside government, in the U. S. and in allied countries. By 2014, the program was $163 billion over seven years behind schedule. Critics also contend that the programs high sunk costs and political momentum make it too big to kill, the JSF program was designed to replace the United States military F-16, A-10, F/A-18 and AV-8B tactical fighter and attack aircraft. To keep development, production, and operating costs down, a design was planned in three variants that share 80 percent of their parts, F-35A, conventional take off and landing variant. F-35B, short-take off and vertical-landing variant, the design goals call for the F-35 to be the premier strike aircraft through 2040 and to be second only to the F-22 Raptor in air supremacy. Although both aircraft met or exceeded requirements, the X-35 design was considered to have less risk, the designation of the new fighter as F-35 is out-of-sequence with standard DoD aircraft numbering, by which it should have been F-24. It came as an even to the company, which had been referring to the aircraft in-house by this expected designation. Instead F-16s have been used as trainers between the T-38 and the F-35. The T-X was intended to be used to train future F-35 pilots, based on wind tunnel testing, Lockheed Martin slightly enlarged its X-35 design into the F-35. The forward fuselage is 5 inches longer to make room for avionics, correspondingly, the horizontal stabilators were moved 2 inches rearward to retain balance and control
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North American B-25 Mitchell
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The North American B-25 Mitchell is an American twin-engine, medium bomber manufactured by North American Aviation. It was named in honor of Major General William Billy Mitchell, used by many Allied air forces, the B-25 served in every theater of World War II and after the war ended many remained in service, operating across four decades. Produced in numerous variants, nearly 10,000 Mitchells rolled from NAA factories and these included a few limited models, such as the United States Marine Corps PBJ-1 patrol bomber and the United States Army Air Forces F-10 reconnaissance aircraft and AT-24 trainers. The Air Corps issued a circular in March 1938 describing the performance they required from the next bombers — a payload of 1,200 lb with a range of 1,200 mi at more than 200 mph and those performance specifications led NAA to submit their NA-40 design. However, the experience from the XB-21 contributed to the design. The single NA-40 built flew first at the end of January 1939 and it went through several modifications to correct problems. These improvements included fitting 1,600 hp Wright R-2600 Twin Cyclone radial engines, in March 1939, in March 1939, North American delivered the substantially redesigned and improved NA-40 to the United States Army Air Corps for evaluation. It was in competition with other manufacturers designs but failed to win orders, however, the French had already opted for a revised Douglas 7B. Unfortunately, the NA-40B was destroyed in a crash on 11 April 1939 while undergoing testing, although the crash was not considered due to a fault with the aircraft design, the Army ordered the DB-7 as the A-20. There was no YB-25 for prototype service tests, in September 1939, the Air Corps ordered the NA-62 into production as the B-25, along with the other new Air Corps medium bomber, the Martin B-26 Marauder off the drawing board. The NA-40 lost out to the Douglas A-20 in the competition, but NAA developed a more advanced design, the NA-40B. Early into B-25 production, NAA incorporated a significant redesign to the wing dihedral, the first nine aircraft had a constant-dihedral, meaning the wing had a consistent, upward angle from the fuselage to the wingtip. Flattening the outer wing panels by giving them a slight anhedral angle just outboard of the engine nacelles nullified the problem, less noticeable changes during this period included an increase in the size of the tail fins and a decrease in their inward tilt at their tops. NAA continued design and development in 1940 and 1941, both the B-25A and B-25B series entered AAF service. The B-25B was operational in 1942, combat requirements lead to further developments. Before the year was over, NAA was producing the B-25C, also in 1942, the manufacturer began design work on the cannon-armed B-25G series. The NA-100 of 1943 and 1944 was an interim armament development at the Kansas City complex known as the B-25D2, Similar armament upgrades by U. S-based commercial modification centers involved about half of the B-25G series. Further development led to the B-25H, B-25J, and B-25J2, the gunship design concept dates to late 1942 and NAA sent a field technical representative to the SWPA
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Avro Lancaster
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The Avro Lancaster is a British four-engined Second World War heavy bomber designed and built by Avro for the Royal Air Force. The Lanc, as it was known, thus became one of the more famous and most successful of the Second World War night bombers. The Lancaster, an evolution of the troublesome Avro Manchester, was designed by Roy Chadwick and was powered by four Rolls-Royce Merlins, or, in one version and this was the largest payload of any bomber in the war. In 1943, a Lancaster was converted to become an engine test bed for the Metropolitan-Vickers F.2 turbojet, Lancasters were later used to test other engines, including the Armstrong Siddeley Mamba and Rolls-Royce Dart turboprops, and the Avro Canada Orenda and STAL Dovern turbojets. Postwar, the Lancaster was supplanted as the RAFs main strategic bomber by the Avro Lincoln, the Lancaster took on the role of long range anti-submarine patrol aircraft and air-sea rescue. In March 1946, a Lancastrian of BSAA flew the first scheduled flight from the new London Heathrow Airport, the resulting aircraft was the Manchester, which, although a capable aircraft, was underpowered and troubled by the unreliability of the Vulture engine. Only 200 Manchesters were built, with the type withdrawn from service in 1942, at first the aircraft was called Avro Type 683 Manchester III and later renamed the Lancaster. The prototype aircraft BT308 was assembled by the Avro experimental flight department at Ringway Airport, test pilot H. A. Bill Thorn took the controls for its first flight at Ringway, on Thursday,9 January 1941. The aircraft proved to be an improvement on its predecessor. Some of the orders for Manchesters were changed in favour of Lancasters. The Lancaster discarded the stubby central third tail fin of the early Manchesters and used the wider span tailplane, the majority of Lancasters built during the war years were manufactured by Avro at their factory at Chadderton near Oldham, Greater Manchester and test flown from Woodford Aerodrome in Cheshire. Other Lancasters were built by Metropolitan-Vickers and Armstrong Whitworth, the Lancaster B III had Packard Merlin engines but was otherwise identical to contemporary B Is, with 3,030 B IIIs built, almost all at Avros Newton Heath factory. The B I and B III were built concurrently and minor modifications were made to both marks as new batches were ordered, of later variants, only the Canadian-built Lancaster B X, manufactured by Victory Aircraft in Malton, Ontario, was produced in significant numbers. The first Lancaster produced in Canada was named the Ruhr Express, the first batch of Canadian Lancasters delivered to England suffered from faulty ailerons. This was traced to the use of unskilled labourers, the Lancaster is a mid-wing cantilever monoplane with an oval all-metal fuselage. The wing was constructed in five sections, the fuselage in five sections. All wing and fuselage sections were built separately and fitted all the required equipment before final assembly. The tail unit had twin fins and rudders
