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64-641: The Martin P4M Mercator was a maritime reconnaissance aircraft built by the Glenn L. Martin Company . The Mercator was an unsuccessful contender for a United States Navy requirement for a long-range maritime patrol bomber, with the Lockheed P2V Neptune chosen instead. It saw a limited life as a long-range electronic reconnaissance aircraft. Its most unusual feature was that it was powered by
128-404: A combustion chamber , and accelerate the exhaust rearwards to provide thrust. Different jet engine configurations include the turbojet and turbofan , sometimes with the addition of an afterburner . Those with no rotating turbomachinery include the pulsejet and ramjet . These mechanically simple engines produce no thrust when stationary, so the aircraft must be launched to flying speed using
192-433: A lifting gas such as helium , hydrogen or hot air , which is less dense than the surrounding air. When the weight of the lifting gas is added to the weight of the aircraft itself, it is same or less than the mass of the air that the craft displaces. Small hot-air balloons, called sky lanterns , were first invented in ancient China prior to the 3rd century BC and used primarily in cultural celebrations, and were only
256-467: A boost during takeoff and combat, two Allison J33 turbojets were fitted in the rear of the two enlarged engine nacelles, the intakes being beneath and behind the radial engines. The jets, like those on most other piston/jet hybrids, burned gasoline instead of jet fuel which eliminated the need for separate fuel tanks. A tricycle undercarriage was fitted, with the nosewheel retracting forwards. The single-wheel main legs retracted into coverless fairings in
320-560: A catapult, like the V-1 flying bomb , or a rocket, for example. Other engine types include the motorjet and the dual-cycle Pratt & Whitney J58 . Compared to engines using propellers, jet engines can provide much higher thrust, higher speeds and, above about 40,000 ft (12,000 m), greater efficiency. They are also much more fuel-efficient than rockets . As a consequence nearly all large, high-speed or high-altitude aircraft use jet engines. Some rotorcraft, such as helicopters , have
384-554: A combination of piston engines and turbojets , the latter being in the rear of the engine nacelles. Work began on the Model 219 in 1944, as a replacement for the PB4Y Privateer long-range patrol bomber, optimised for long range minelaying missions, with the first flight being on 20 October 1946. A large and complicated aircraft, it was powered by two Pratt & Whitney R4360 Wasp Major 28-cylinder radial engines . To give
448-726: A few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes , helicopters , airships (including blimps ), gliders , paramotors , and hot air balloons . The human activity that surrounds aircraft is called aviation . The science of aviation, including designing and building aircraft, is called aeronautics . Crewed aircraft are flown by an onboard pilot , whereas unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers . Aircraft may be classified by different criteria, such as lift type, aircraft propulsion (if any), usage and others. Flying model craft and stories of manned flight go back many centuries; however,
512-638: A greater wingspan (94m/260 ft) than any current aircraft and a tail height equal to the tallest (Airbus A380-800 at 24.1m/78 ft) — flew only one short hop in the late 1940s and never flew out of ground effect . The largest civilian airplanes, apart from the above-noted An-225 and An-124, are the Airbus Beluga cargo transport derivative of the Airbus A300 jet airliner, the Boeing Dreamlifter cargo transport derivative of
576-674: A marginal case. The forerunner of the fixed-wing aircraft is the kite . Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the wind blowing over its wings to provide lift. Kites were the first kind of aircraft to fly and were invented in China around 500 BC. Much aerodynamic research was done with kites before test aircraft, wind tunnels , and computer modelling programs became available. The first heavier-than-air craft capable of controlled free-flight were gliders . A glider designed by George Cayley carried out
640-794: A maximum loaded weight of 550–700 t (1,210,000–1,540,000 lb), it was also the heaviest aircraft built to date. It could cruise at 500 mph (800 km/h; 430 kn). The aircraft was destroyed during the Russo-Ukrainian War . The largest military airplanes are the Ukrainian Antonov An-124 Ruslan (world's second-largest airplane, also used as a civilian transport), and American Lockheed C-5 Galaxy transport, weighing, loaded, over 380 t (840,000 lb). The 8-engine, piston/propeller Hughes H-4 Hercules "Spruce Goose" — an American World War II wooden flying boat transport with
704-719: A merger offer from the Wright Company , creating the Wright-Martin Aircraft Company. This merger did not function well, so Glenn Martin left to form a second Glenn L. Martin Company on September 10, 1917. This new company was headquartered in Cleveland, Ohio . In 1913, Mexican insurgents from the northwestern state of Sonora bought a single-seater Martin Pusher biplane in Los Angeles with
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#1732779552863768-569: A payload of up to 22,050 lb (10,000 kg). The largest aircraft by weight and largest regular fixed-wing aircraft ever built, as of 2016 , was the Antonov An-225 Mriya . That Soviet-built ( Ukrainian SSR ) six-engine transport of the 1980s was 84 m (276 ft) long, with an 88 m (289 ft) wingspan. It holds the world payload record, after transporting 428,834 lb (194,516 kg) of goods, and has flown 100 t (220,000 lb) loads commercially. With
832-588: A powered "tug" aircraft. For a glider to maintain its forward air speed and lift, it must descend in relation to the air (but not necessarily in relation to the ground). Many gliders can "soar", i.e. , gain height from updrafts such as thermal currents. The first practical, controllable example was designed and built by the British scientist and pioneer George Cayley , whom many recognise as the first aeronautical engineer. Common examples of gliders are sailplanes , hang gliders and paragliders . Balloons drift with
896-491: A powered rotary wing or rotor , where the rotor disc can be angled slightly forward so that a proportion of its lift is directed forwards. The rotor may, like a propeller, be powered by a variety of methods such as a piston engine or turbine. Experiments have also used jet nozzles at the rotor blade tips . Aircraft are designed according to many factors such as customer and manufacturer demand, safety protocols and physical and economic constraints. For many types of aircraft
960-564: A powerful Centaur rocket upper stage, was used to launch the heavy Cassini space probe to the planet Saturn in 1997. The Cassini probe orbited Saturn from 2004 to 2017, successfully returning mountains of scientific data. The halting of production of the Titan IV in 2004 brought to an end production of the last rocket able to carry a heavier payload than the Space Shuttle, which itself ended in 2011. The Martin Company merged with
1024-577: A rigid basket or gondola slung below it to carry its payload. Early aircraft, including airships , often employed flexible doped aircraft fabric covering to give a reasonably smooth aeroshell stretched over a rigid frame. Later aircraft employed semi- monocoque techniques, where the skin of the aircraft is stiff enough to share much of the flight loads. In a true monocoque design there is no internal structure left. The key structural parts of an aircraft depend on what type it is. Lighter-than-air types are characterised by one or more gasbags, typically with
1088-420: A supporting structure of flexible cables or a rigid framework called its hull. Other elements such as engines or a gondola may also be attached to the supporting structure. Heavier-than-air types are characterised by one or more wings and a central fuselage . The fuselage typically also carries a tail or empennage for stability and control, and an undercarriage for takeoff and landing. Engines may be located on
1152-522: Is a lifting body , which has no wings, though it may have small stabilizing and control surfaces. Wing-in-ground-effect vehicles are generally not considered aircraft. They "fly" efficiently close to the surface of the ground or water, like conventional aircraft during takeoff. An example is the Russian ekranoplan nicknamed the " Caspian Sea Monster ". Man-powered aircraft also rely on ground effect to remain airborne with minimal pilot power, but this
1216-437: 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 (which may then be rigid or non-rigid). Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back. These soon became known as blimps . During World War II , this shape
1280-452: Is only because they are so underpowered—in fact, the airframe is capable of flying higher. Rotorcraft, or rotary-wing aircraft, use a spinning rotor with aerofoil cross-section blades (a rotary wing ) to provide lift. Types include helicopters , autogyros , and various hybrids such as gyrodynes and compound rotorcraft. Helicopters have a rotor turned by an engine-driven shaft. The rotor pushes air downward to create lift. By tilting
1344-623: Is stored in tanks, usually in the wings but larger aircraft also have additional fuel tanks in the fuselage . Propeller aircraft use one or more propellers (airscrews) to create thrust in a forward direction. The propeller is usually mounted in front of the power source in tractor configuration but can be mounted behind in pusher configuration . Variations of propeller layout include contra-rotating propellers and ducted fans . Many kinds of power plant have been used to drive propellers. Early airships used man power or steam engines . The more practical internal combustion piston engine
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#17327795528631408-475: Is the Lockheed SR-71 Blackbird , a U.S. reconnaissance jet fixed-wing aircraft, having reached 3,530 km/h (2,193 mph) on 28 July 1976. Gliders are heavier-than-air aircraft that do not employ propulsion once airborne. Take-off may be by launching forward and downward from a high location, or by pulling into the air on a tow-line, either by a ground-based winch or vehicle, or by
1472-629: The Bell Boeing V-22 Osprey ), tiltwing , tail-sitter , and coleopter aircraft have their rotors/ propellers horizontal for vertical flight and vertical for forward flight. The smallest aircraft are toys/recreational items, and nano aircraft . The largest aircraft by dimensions and volume (as of 2016) is the 302 ft (92 m) long British Airlander 10 , a hybrid blimp, with helicopter and fixed-wing features, and reportedly capable of speeds up to 90 mph (140 km/h; 78 kn), and an airborne endurance of two weeks with
1536-693: The Boeing 747 jet airliner/transport (the 747-200B was, at its creation in the 1960s, the heaviest aircraft ever built, with a maximum weight of over 400 t (880,000 lb)), and the double-decker Airbus A380 "super-jumbo" jet airliner (the world's largest passenger airliner). The fastest fixed-wing aircraft and fastest glider, is the Space Shuttle , which re-entered the atmosphere at nearly Mach 25 or 17,500 mph (28,200 km/h) The fastest recorded powered aircraft flight and fastest recorded aircraft flight of an air-breathing powered aircraft
1600-902: The EA-3B Skywarrior , which, being carrier-based, had a greater degree of flexibility, and the larger Lockheed WV-2Q Warning Star . Final withdrawal from service was in 1960 after which all of the remaining P4Ms were scrapped. Data from United States Navy aircraft since 1911, Naval Fighters #37: Martin P4M-1/-1Q Mercator General characteristics Performance Armament Avionics Aircraft of comparable role, configuration, and era Related lists [REDACTED] Media related to Martin P4M Mercator at Wikimedia Commons Glenn L. Martin Company The Glenn L. Martin Company , also known as The Martin Company from 1917 to 1961,
1664-637: The Harrier jump jet and Lockheed Martin F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight. A pure rocket is not usually regarded as an aerodyne because its flight does not depend on interaction with the air at all (and thus can even fly in the vacuum of outer space ); however, many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles that obtain aerodynamic lift at very high speed due to airflow over their bodies are
1728-817: The PBM Mariner and JRM Mars flying boats, widely used for air-sea rescue , anti-submarine warfare and transport. The 1941 Office for Emergency Management film Bomber was filmed in the Martin facility in Baltimore, and showed aspects of the production of the B-26. Martin ranked 14th among U.S. corporations in the value of wartime production contracts. The company built 1,585 B-26 Marauders and 531 Boeing B-29 Superfortresses at its new bomber plant in Nebraska , just south of Omaha at Offutt Field . Among
1792-697: The Titan IIIA , the more-important Titan IIIC , and the Titan IIIE . Besides hundreds of Earth satellites, these rockets were essential for the sending to outer space of the two space probes of the Voyager Project to the outer planets , the two space probes of the Viking Project to Mars , and the two Helios probes into low orbits around the Sun (closer, even, than Mercury ). Finally,
1856-628: The 1930s, Martin built flying boats for the U.S. Navy , and the innovative Martin B-10 bomber for the Army. The Martin Company also produced the noted China Clipper flying boats used by Pan American Airways for its transpacific San Francisco to the Philippines route. During World War II, a few of Martin's most successful designs were the B-26 Marauder and A-22 Maryland bombers,
1920-435: 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 a rigid outer framework and separate aerodynamic skin surrounding
1984-819: The American-Marietta Corporation, a chemical-products and construction-materials manufacturer, in 1961, to form the Martin Marietta Corporation . In 1995, Martin Marietta, then the nation's third-largest defense contractor, merged with the Lockheed Corporation , then the nation's second-largest defense contractor, to form the Lockheed Martin Corporation , becoming the largest such company in the world. The Martin Company employed many of
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2048-676: The B-29s manufactured there were all the Silverplate aircraft, including Enola Gay and Bockscar , which dropped the two war-ending atomic bombs on Hiroshima and Nagasaki , Japan . On April 22, 1957, the company name was changed to the Martin Company. Postwar efforts in aeronautics by the Martin Company included two unsuccessful prototype bombers, the XB-48 and the XB-51 ,
2112-734: The Martin Company merged with American-Marietta Corporation , a large industrial conglomerate, forming the Martin Marietta corporation. In turn, Martin Marietta in 1995 merged with aerospace giant Lockheed Corporation to form the Lockheed Martin corporation. Glenn L. Martin Company was founded by aviation pioneer Glenn Luther Martin on August 16, 1912. He started the company building military training aircraft in Santa Ana, California , and in September 1916, Martin accepted
2176-626: The US Air Force required a booster rocket that could launch heavier satellites than either the Titan IIIE or the Space Shuttle . The Martin Company responded with its extremely large Titan IV series of rockets. When the Titan IV came into service, it could carry a heavier payload to orbit than any other rocket in production. Besides its use by the Air Force to launch its sequence of very heavy reconnaissance satellites , one Titan IV, with
2240-689: The US Army's Pershing missile. The Martin Company was one of two finalists for the command and service modules of the Apollo Program . The National Aeronautics and Space Administration (NASA) awarded the design and production contracts for these to the North American Aviation Corporation. The Martin Company went further in the production of larger booster rockets for NASA and the U.S. Air Force with its Titan III series of over 100 rockets produced, including
2304-470: The aircraft's weight. There are two ways to produce dynamic upthrust — aerodynamic lift by having air flowing past an aerofoil (such dynamic interaction of aerofoils with air is the origin of the term "aerodyne"), or powered lift in the form of reactional lift from downward engine thrust . Aerodynamic lift involving wings is the most common, and can be achieved via two methods. Fixed-wing aircraft ( airplanes and gliders ) achieve airflow past
2368-501: The autogyro moves forward, air blows upward across the rotor, making it spin. This spinning increases the speed of airflow over the rotor, to provide lift. Rotor kites are unpowered autogyros, which are towed to give them forward speed or tethered to a static anchor in high-wind for kited flight. Compound rotorcraft have wings that provide some or all of the lift in forward flight. They are nowadays classified as powered lift types and not as rotorcraft. Tiltrotor aircraft (such as
2432-481: The coast (about 30 nmi or 56 km offshore) of Vietnam, China, North Korea and the eastern Soviet Union, and were of a highly secret nature; the aircraft sometimes masqueraded as regular P2V Neptunes in radio communications, and often flew with false serial numbers (Bureau Numbers) painted under the tail. Operational missions were always flown at night, during the dark with the moon when possible, and with no external running lights. The Mercators were replaced by
2496-435: The design process is regulated by national airworthiness authorities. The key parts of an aircraft are generally divided into three categories: The approach to structural design varies widely between different types of aircraft. Some, such as paragliders, comprise only flexible materials that act in tension and rely on aerodynamic pressure to hold their shape. A balloon similarly relies on internal gas pressure, but may have
2560-734: The end of hostilities. A follow-up design, the MB-2 , proved successful; 20 were ordered by the Army Air Service , the first five of them under the company designation and the last 15 as the NBS-1 (Night Bomber, Short range). Although the War Department ordered 110 more, it retained the ownership rights of the design, and put the order out for bid. The production orders were given to other companies that had bid lower, Curtiss (50), L.W.F. Engineering (35), and Aeromarine (25). The design
2624-595: The first known air-to-naval bombing runs in history. For the Dutch East Indies, several planes were delivered, with the first flight on November 6, 1915. It involved two Type TEs, six Type TTs, and eight Type Rs. Martin's first big success came during World War I with the MB-1 bomber , a large biplane design ordered by the United States Army on January 17, 1918. The MB-1 entered service after
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2688-477: The first manned ascent — and safe descent — in modern times took place by larger hot-air balloons developed in the 18th century. Each of the two World Wars led to great technical advances. Consequently, the history of aircraft can be divided into five eras: Lighter-than-air aircraft or 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 cells or canopies, filled with
2752-532: The first true manned, controlled flight in 1853. The first powered and controllable fixed-wing aircraft (the airplane or aeroplane) was invented by Wilbur and Orville Wright . Besides the method of propulsion (if any), fixed-wing aircraft are in general characterized by their wing configuration . The most important wing characteristics are: A variable geometry aircraft can change its wing configuration during flight. A flying wing has no fuselage, though it may have small blisters or pods. The opposite of this
2816-456: The founders and chief engineers of the American aerospace industry, including: Martin also taught William Boeing how to fly and sold him his first airplane. Aircraft An aircraft ( pl. : aircraft) is a vehicle that is able to fly by gaining support from the air . It counters the force of gravity by using either static lift or the dynamic lift of an airfoil , or, in
2880-418: The fuselage or wings. On a fixed-wing aircraft the wings are rigidly attached to the fuselage, while on a rotorcraft the wings are attached to a rotating vertical shaft. Smaller designs sometimes use flexible materials for part or all of the structure, held in place either by a rigid frame or by air pressure. The fixed parts of the structure comprise the airframe . The source of motive power for an aircraft
2944-514: The gas bags, were produced, the Zeppelins being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so "airship" came to be synonymous with these aircraft. Then several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a "balloon" is an unpowered aerostat and an "airship"
3008-464: The intention of attacking federal naval forces that were attacking the port of Guaymas . The aircraft was shipped on May 5, 1913, in five crates to Tucson, Arizona , via Wells Fargo Express , and then moved through the border into Mexico to the town of Naco, Sonora . The aircraft, named Sonora by the insurgents, was reassembled there and fitted with a second seat for a bomber position. The Sonora , armed with rudimentary 3-inch pipe bombs, performed
3072-596: The marginally successful AM Mauler , the successful B-57 Canberra tactical bombers , the P5M Marlin and P6M SeaMaster seaplanes , and the Martin 4-0-4 twin-engined passenger airliner. The Martin Company moved into the aerospace manufacturing business. It produced the Vanguard rocket , used by the American space program as one of its first satellite booster rockets as part of Project Vanguard . The Vanguard
3136-411: The rotor forward, the downward flow is tilted backward, producing thrust for forward flight. Some helicopters have more than one rotor and a few have rotors turned by gas jets at the tips. Some have a tail rotor to counteract the rotation of the main rotor, and to aid directional control. Autogyros have unpowered rotors, with a separate power plant to provide thrust. The rotor is tilted backward. As
3200-436: The second type of aircraft to fly, the first being kites , which were also first invented in ancient China over two thousand years ago (see Han Dynasty ). 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," with smaller passenger types as "Air yachts." In
3264-444: The short and deep bay popular in American bombers. This gave greater flexibility in payload, including long torpedoes, bombs, mines, depth charges or extended-range fuel tanks. The US Navy chose the smaller, simpler, cheaper and better performing P2V Neptune for the maritime patrol requirement, but nineteen aircraft were ordered in 1947 for high-speed minelaying purposes. The P4M entered service with Patrol Squadron 21 (VP-21) in 1950,
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#17327795528633328-590: The squadron deploying to NAS Port Lyautey in French Morocco . It remained in use with VP-21 until February 1953. From 1951, the 18 surviving production P4Ms were modified for the electronic reconnaissance (or SIGINT , for signals intelligence ) mission as the P4M-1Q , to replace the PB4Y-2 Privateer . The crew was increased to 14 and later 16 to operate all the surveillance gear, and the aircraft
3392-530: The tether or kite line ; they rely on virtual or real wind blowing over and under them to generate lift and drag. Kytoons are balloon-kite hybrids that are shaped and tethered to obtain kiting deflections, and can be lighter-than-air, neutrally buoyant, or heavier-than-air. Powered aircraft have one or more onboard sources of mechanical power, typically aircraft engines although rubber and manpower have also been used. Most aircraft engines are either lightweight reciprocating engines or gas turbines . Engine fuel
3456-460: The wind, though normally the pilot can control the altitude, either by heating the air or by releasing ballast, giving some directional control (since the wind direction changes with altitude). A wing-shaped hybrid balloon can glide directionally when rising or falling; but a spherically shaped balloon does not have such directional control. Kites are aircraft that are tethered to the ground or other object (fixed or mobile) that maintains tension in
3520-431: The wing. A flexible wing is a wing made of fabric or thin sheet material, often stretched over a rigid frame, similar to the flight membranes on many flying and gliding animals . A kite is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed, or rotary. With powered lift, the aircraft directs its engine thrust vertically downward. V/STOL aircraft, such as
3584-402: The wings by having the entire aircraft moving forward through the air, while rotorcraft ( helicopters and autogyros ) do so by having mobile, elongated wings spinning rapidly around a mast in an assembly known as the rotor . As aerofoils, there must be air flowing over the wing to create pressure difference between above and below, thus generating upward lift over the entire wetted area of
3648-460: The wings, so that the sides of the wheels could be seen even when retracted. The wings themselves, unusually, had a different airfoil cross-section on the inner wings than the outer. Heavy defensive armament was fitted, with two 20 mm (.79 in) cannon in an Emerson nose turret and a Martin tail turret, and two 0.5 in (12.7 mm) machine guns in a Martin dorsal turret. The bomb bay was, like British practice, long and shallow rather than
3712-531: Was an American aircraft and aerospace manufacturing company founded by aviation pioneer Glenn L. Martin . The Martin Company produced many important aircraft for the defense of the US and allies, especially during World War II and the Cold War . During the 1950s and '60s, the Martin Company moved from the aircraft industry into the guided missile , space exploration , and space utilization industries. In 1961,
3776-468: Was fitted with a large number of different antennae. Starting in October 1951, electronic surveillance missions were flown from U.S. Naval Station Sangley Point in the Philippines , later from Naval Air Station Iwakuni , Japan , and Naval Air Station Atsugi , Japan, by a secretive unit that eventually gained the designation Fleet Air Reconnaissance Squadron One (VQ-1) . Long missions were flown along
3840-675: Was of the NASA X-43 A Pegasus , a scramjet -powered, hypersonic , lifting body experimental research aircraft, at Mach 9.68 or 6,755 mph (10,870 km/h) on 16 November 2004. Prior to the X-43A, the fastest recorded powered airplane flight, and still the record for the fastest manned powered airplane, was the North American X-15 , rocket-powered airplane at Mach 6.7 or 7,274 km/h (4,520 mph) on 3 October 1967. The fastest manned, air-breathing powered airplane
3904-400: Was the first American space exploration rocket designed from scratch to be an orbital launch vehicle — rather than being a modified ballistic missile (such as the U.S. Army's Juno I ). Martin also designed and manufactured the huge and heavily armed Titan I and LGM-25C Titan II intercontinental ballistic missiles (ICBMs). Martin Company of Orlando, Florida, was the prime contractor for
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#17327795528633968-948: Was the only standard bomber used by the Air Service until 1930, and was used by seven squadrons of the Air Service/Air Corps: Four in Virginia, two in Hawaii, and one in the Philippines. In 1924, the Martin Company underbid Curtiss for the production of a Curtiss-designed scout bomber, the SC-1 , and ultimately Martin produced 404 of these. In 1929, Martin sold the Cleveland plant and built a new one in Middle River, Maryland , northeast of Baltimore . During
4032-490: Was used for virtually all fixed-wing aircraft until World War II and is still used in many smaller aircraft. Some types use turbine engines to drive a propeller in the form of a turboprop or propfan . Human-powered flight has been achieved, but has not become a practical means of transport. Unmanned aircraft and models have also used power sources such as electric motors and rubber bands. Jet aircraft use airbreathing jet engines , which take in air, burn fuel with it in
4096-439: Was widely adopted for tethered balloons ; in windy weather, this both reduces the strain on the tether and stabilizes the balloon. The nickname blimp was adopted along with the shape. In modern times, any small dirigible or airship is called a blimp, though a blimp may be unpowered as well as powered. Heavier-than-air aircraft or aerodynes are denser than air and thus must find some way to obtain enough lift that can overcome
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