1.
Douglas Aircraft Company
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The Douglas Aircraft Company was an American aerospace manufacturer based in Southern California. It was founded in 1921 by Donald Wills Douglas, Sr. Douglas Aircraft Company largely operated as a division of McDonnell Douglas after the merger. MD later merged with Boeing in 1997, the Douglas Aircraft Company was founded by Donald Wills Douglas, Sr. on July 22,1921 in Santa Monica, California, following dissolution of the Davis-Douglas Company. An early claim to fame was the first circumnavigation of the world by air in Douglas airplanes in 1924. In 1923, the U. S. Army Air Service was interested in carrying out a mission to circumnavigate the Earth for the first time by aircraft, Donald Douglas proposed a modified Douglas DT to meet the Armys needs. The two-place, open cockpit DT biplane torpedo bomber had previously produced for the U. S. Navy. The DTs were taken from the lines at the companys manufacturing plants in Rock Island, Illinois and Dayton. The modified aircraft known as the Douglas World Cruiser, also was the first major project for Jack Northrop who designed the system for the series. After the prototype was delivered in November 1923, upon the completion of tests on 19 November. Due to the expedition ahead, spare parts, including 15 extra Liberty L-12 engines,14 extra sets of pontoons. These were sent to airports along the route, the last of these aircraft was delivered to the U. S. Army on 11 March 1924. After the success of the World Cruiser, the Army Air Service ordered six similar aircraft as observation aircraft. The success of the DWC established the Douglas Aircraft Company among the aircraft companies of the world. Douglas adopted a logo that showed aircraft circling a globe, replacing the original winged heart logo, the logo evolved into an aircraft, a rocket, and a globe. It was later adopted by the McDonnell Douglas Corporation, and then became the basis of the current logo of the Boeing Company after their 1997 merger, many Douglas aircraft had long service lives. Douglas Aircraft designed and built a variety of aircraft for the U. S. military, including the Navy, Army Air Forces, Marine Corps, Air Force. The company initially built torpedo bombers for the U. S. Navy, within five years, the company was building about 100 aircraft annually. Among the early employees at Douglas were Ed Heinemann, Dutch Kindelberger, and Jack Northrop, the company retained its military market and expanded into amphibian airplanes in the late 1920s, also moving its facilities to Clover Field at Santa Monica, California
2.
United States Army Air Corps
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The United States Army Air Corps was the military aviation arm of the United States of America between 1926 and 1941. The USAAC was renamed from the earlier United States Army Air Service on 2 July 1926, the Air Corps became the United States Army Air Forces on 20 June 1941, giving it greater autonomy from the Armys middle-level command structure. The separation of the Air Corps from control of its combat units caused problems of unity of command that became more acute as the Air Corps enlarged in preparation for World War II. This was resolved by the creation of the Army Air Forces, the U. S. Army Air Service had a brief but turbulent history. In early 1926 the Military Affairs Committee of the Congress rejected all bills set forth before it on both sides of the issue. They fashioned a compromise in which the findings of the Morrow Board were enacted as law, while providing the air arm a five-year plan for expansion and development. The legislation changed the name of the Air Service to the Air Corps, thereby strengthening the conception of military aviation as an offensive, the Air Corps Act became law on 2 July 1926. Two additional brigadier generals would serve as assistant chiefs of the Air Corps, previous provisions of the National Defense Act of 1920 that all flying units be commanded only by rated personnel and that flight pay be awarded were continued. The Air Corps also retained the Prop and Wings as its branch insignia through its disestablishment in 1947, patrick became Chief of the Air Corps and Brig. Gen. James E. Fechet continued as his first assistant chief. The Air Corps Act of 2 July 1926 effected no fundamental innovation, the change in designation meant no change in status, the Air Corps was still a combatant branch of the Army with less prestige than the Infantry. The Air Corps Act gave authorization to carry out an expansion program. However, a lack of appropriations caused the beginning of the program to be delayed until 1 July 1927. The act authorized expansion to 1,800 airplanes,1,650 officers, none of the goals were reached by July 1932. Organizationally the Air Corps doubled from seven to fifteen groups, but the expansion was meaningless because all were seriously understrength in aircraft and pilots. Air Corps groups added 1927–1937 ¹Inactivated on 20 May 1937 ²Redesignated 17th Attack Group, 17th Bomb Group As units of the Air Corps increased in number, so did higher command echelons. The 1st Bomb Wing was activated in 1931, followed by the 3rd Attack Wing in 1932 to protect the Mexican border, the three wings became the foundation of General Headquarters Air Force upon its activation in 1935. In 1927 the Air Corps adopted a new scheme for painting its aircraft. The wings and tails of aircraft were painted yellow, with the words U. S
3.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
4.
Liberty L-12
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The Liberty L-12 was an American 27-litre water-cooled 45° V-12 aircraft engine of 400 hp designed for a high power-to-weight ratio and ease of mass production. It was succeeded by the Packard 1A-2500, the two left their positions at the Fageol Motors Co. putting an end to the short production of the most luxurious automobile of the period. They were given the task of designing as rapidly as possible an aircraft engine that would rival if not surpass those of Great Britain, France, the Board specified that the engine would have a high power-to-weight ratio and be adaptable to mass production. The Board brought Vincent and Hall together on 29 May 1917 at the Willard Hotel in Washington, in July 1917, an eight-cylinder prototype assembled by Packards Detroit plant arrived in Washington for testing, and in August, the 12-cylinder version was tested and approved. Hall-Scott in California was considered too small to receive a production order, manufacturing by multiple factories was facilitated by its modular design. Lincoln constructed a new plant in record time, devoted entirely to Liberty engine production, by the time of the Armistice with Germany, the various companies had produced 13,574 Liberty engines, attaining a production rate of 150 engines per day. Production continued after the war, for a total of 20,478 engines built between July 4,1917 and 1919, although it is widely reported otherwise, a few Liberty engines did see action in France as power for the American version of the Airco DH.4. This led to Henry Leland leaving Cadillac to form the Lincoln Motor Company to make Liberty engines and he quickly gained a $10,000,000 government contract to build 6,000 engines. Subsequently the order was increased to 9,000 units, with the option to produce 8,000 more if the government needed them, more than 16,000 Liberty engines were produced during the calendar year 1918. To November 11,1918, more than 14,000 Liberty engines were produced, Lincoln had delivered 6,500 of the 400 hp, V-12, overhead camshaft engines when production ceased in January 1919. Durant later changed his mind and both Cadillac and Buick produced the engines, the Liberty engine was a modular design where four or six cylinders could be used in one or two banks, with the cylinders designed as individual units, each with their own water jacket. A pair of the 52 engines produced were destroyed by William Christmas testing his so-called Christmas Bullet fighter, an inverted Liberty 12-A referred to as the V-1650 was produced up to 1926 by Packard. The same designation was applied to the Packard V-1650 Merlin. This was a World War II Packard produced version of the Rolls-Royce Merlin, the Allison VG-1410 was an air-cooled inverted Liberty L-12, with a geared super-charger and Allison epicyclic propeller reduction gear and reduced displacement. An 8-cylinder V engine using Liberty cylinders in banks of four at 90°, the Nuffield Liberty tank engine was licensed and produced in World War II by the UK car manufacturer Nuffield. It was used in early Cruiser tanks, the Crusader, the Cavalier, the Nuffield Liberty ran through multiple versions, Mark I, US built engines modified in Britain. Modification incorporated new carburettors and a new system from Solex, revision of the crankcase breather, new timing gear. This produced 340 hp when governed to 1,500 rpm with the new carburettors, the air compressor wasnt used, and was removed on later engines Mark III, IIIA and IIIB, made for the Crusader tank
5.
Radiator
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Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, despite the name, most radiators transfer the bulk of their heat via convection instead of thermal radiation, though the term convector is used more narrowly, see radiation and convection, below. The Roman hypocaust, a type of radiator for building heating, was described in 15 AD. The heating radiator was invented by Franz San Galli, a Prussian-born Russian businessman living in St. Petersburg, in practice, the term radiator refers to any of a number of devices in which a liquid circulates through exposed pipes. The term convector refers to a class of devices in which the source of heat is not directly exposed, radiators are commonly used to heat buildings. To cool down the engine, a coolant is passed through the engine block, the hot coolant is then fed into the inlet tank of the radiator, from which it is distributed across the radiator core through tubes to another tank on the opposite end of the radiator. The fins then release the heat to the ambient air, fins are used to greatly increase the contact surface of the tubes to the air, thus increasing the exchange efficiency. The cooled coolant is fed back to the engine, and the cycle repeats, normally, the radiator does not reduce the temperature of the coolant back to ambient air temperature, but it is still sufficiently cooled to keep the engine from overheating. This coolant is usually water-based, with the addition of glycols to prevent freezing, however, the coolant may also be an oil. The first engines used thermosiphons to circulate the coolant, today, however, all, up to the 1980s, radiator cores were often made of copper and brass. Starting in the 1970s, use of aluminium increased, eventually taking over the vast majority of vehicular radiator applications, the main inducements for aluminium are reduced weight and cost. However, the cooling properties of Copper-Brass over Aluminium makes it preferential for high performance vehicles or stationary applications. In particular MW-class installations, copper-brass constructions are still dominant, since air has a lower heat capacity and density than liquid coolants, a fairly large volume flow rate must be blown through the radiator core to capture the heat from the coolant. Radiators often have one or more fans that blow air through the radiator, to save fan power consumption in vehicles, radiators are often behind the grille at the front end of a vehicle. Ram air can give a portion or all of the cooling air flow when the coolant temperature remains below the systems designed maximum temperature. As electronic devices become smaller, the problem of dispersing waste heat becomes more difficult, tiny radiators known as heat sinks are used to convey heat from the electronic components into a cooling air stream. Radiators are found as components of some spacecraft and these radiators work by radiating heat energy away as light because in the vacuum of space neither convection nor conduction can work to transfer heat away. On the International Space Station these can be seen clearly as large white panels attached to the main truss and they can be found on both manned and unmanned craft
6.
Biplane
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A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, while a biplane wing structure has a structural advantage over a monoplane, it produces more drag than a similar unbraced or cantilever monoplane wing. Improved structural techniques, better materials and the quest for greater speed made the biplane configuration obsolete for most purposes by the late 1930s. Biplanes offer several advantages over conventional cantilever monoplane designs, they permit lighter wing structures, low wing loading, however, interference between the airflow over each wing increases drag substantially, and biplanes generally need extensive bracing, which causes additional drag. Biplanes are distinguished from tandem wing arrangements, where the wings are placed forward and aft, instead of above, the term is also occasionally used in biology, to describe the wings of some flying animals. In a biplane aircraft, two wings are placed one above the other, either or both of the main wings can support ailerons, while flaps are more usually positioned on the lower wing. Bracing is nearly always added between the upper and lower wings, in the form of wires and/or slender interplane struts positioned symmetrically on either side of the fuselage. The primary advantage of the biplane over the traditional single plane or monoplane is to combine great stiffness with light weight. A braced monoplane wing must support itself fully, while the two wings of a help to stiffen each other. The biplane is therefore inherently stiffer than the monoplane, also, the structural forces in the spars of a biplane wing tend to be lower, so the wing can use less material to obtain the same overall strength and is therefore much lighter. A disadvantage of the biplane was the need for extra struts to space the wings apart, the low power supplied by the engines available in the first years of aviation meant that aeroplanes could only fly slowly. This required an even lower stalling speed, which in turn required a low wing loading, combining both large wing area with light weight. A biplane wing of a span and chord has twice the area of a monoplane the same size and so can fly more slowly. Alternatively, a wing of the same area as a monoplane has lower span and chord, reducing the structural forces. Biplanes suffer aerodynamic interference between the two planes and this means that a biplane does not in practice obtain twice the lift of the similarly-sized monoplane. The farther apart the wings are spaced the less the interference, given the slow speed and low power of early aircraft, the drag penalty of the wires and struts and the mutual interference of airflows were relatively minor and acceptable factors. The smaller biplane wing also allows greater maneuverability, during World War One, this further enhanced the dominance of the biplane and, despite the need for speed, military aircraft were among the last to abandon the biplane form. Specialist sports Aerobatic biplanes are still occasionally made, biplanes were originally designed with the wings positioned directly one above the other
7.
National Guard of the United States
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All members of the National Guard of the United States are also members of the militia of the United States as defined by 10 U. S. C. National Guard units are under the control of the state. The majority of National Guard soldiers and airmen hold a civilian job full-time while serving part-time as a National Guard member, local militias were formed from the earliest English colonization of the Americas in 1607. The first colony-wide militia was formed by Massachusetts in 1636 by merging small older local units, the various colonial militias became state militias when the United States became independent. The title National Guard was used from 1824 by some New York State militia units, National Guard became a standard nationwide militia title in 1903, and specifically indicated reserve forces under mixed state and federal control from 1933. The first muster of militia forces in what is today the United States took place on September 16,1565, appropriately enough, this muster occurred in the shadow of an oncoming hurricane. This Spanish militia tradition and the English tradition that would be established to the north would provide the nucleus for Colonial defense in the New World. The militia tradition continued with the first permanent English settlements in the New World, Jamestown Colony and Plymouth Colony both had militia forces, which initially consisted of every able bodied adult male. By the mid-1600s every town had at least one militia company, as a result of the Spanish–American War, Congress was called upon to reform and regulate the training and qualification of state militias. The first national laws regulating the militia were the Militia acts of 1792, in 1903, with passage of the Dick Act, the predecessor to the modern-day National Guard was formed. It required the states to divide their militias into two sections, the law recommended the title National Guard for the first section, known as the organized militia, and Reserve Militia for all others. During World War I, Congress passed the National Defense Act of 1916, Congress also authorized the states to maintain Home Guards, which were reserve forces outside the National Guards being deployed by the Federal Government. The National Guard of the states, territories, and the District of Columbia serves as part of the first-line of defense for the United States. C. Where the National Guard operates under the President of the United States or his designee, the governors exercise control through the state adjutants general. The National Guard may be called up for duty by the governors to help respond to domestic emergencies and disasters, such as hurricanes, floods. The National Guard is administered by the National Guard Bureau, which is a joint activity of the Army, the National Guard Bureau provides a communication channel for state National Guards to the DoD. S. C. The National Guard Bureau is headed by the Chief of the National Guard Bureau, prior to 2008, the functions of Agricultural Development Teams were within Provincial Reconstruction Teams of the US Government. Today, ADTs consist of soldiers and airmen from the Army National Guard, today, ADTs bring an effective platform for enhanced dialogue, building confidence, sharing interests, and increasing cooperation amongst the disparate peoples and tribes of Afghanistan
8.
Strut
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A strut is a structural component designed to resist longitudinal compression. Struts provide outwards-facing support in their direction, which can be used to keep two other components separate, performing the opposite function of a tie. They are commonly used in architecture and engineering, as components of an automobile chassis, struts can be passive braces to reinforce the chassis and/or body, or active components of the suspension. This means that a strut must have a more rugged design, the most common form of strut in an automobile is the MacPherson strut. MacPherson struts are often purchased by the automakers in sets of four completed sub-assemblies, the MacPherson strut combines a shock absorber and a spring in a single unit, by means of which each wheel is attached to the car body. Transportation-related struts are used in load bearing applications ranging from both highway and off-road suspensions to automobile hood and hatch window supports to aircraft wing supports, in vehicle suspension systems, struts are most commonly an assembly of coil-over spring and shock absorber. Signs of strut failure include a popping or clicking noise when the wheel of the vehicle is turned. This noise is caused by a worn out bearing, most strut failure is gradual, and becomes evident as a more trampoline-like ride, rough travel over bumps, and tire noise/ vibrations. A tendency for the front of the vehicle to nose dive when applying the brakes and to rear upwards when accelerating are other signs of strut failure and these symptoms will only tend to worsen until the struts are replaced with new components. Many strut replacements on non-commercial vehicles are in fact only replacements of the shock absorber, vehicle handling is one of the easiest aspects of a potential new car purchase for a buyer to assess without professional assistance. In piping, struts restrain movement of a component in one direction while allowing movement or contraction in another direction, Strut is a common name in timber framing for a support or brace of scantlings lighter than a post. Frequently struts are found in roof framing from either a tie beam or a king post to a principal rafter, struts may be vertically plumb or leaning and may be straight or curved. In the U. K. Strutting or blocking between floor joists adds strength to the floor system, bracing struts and wires of many kinds were extensively used in early aircraft to stiffen and strengthen, and sometimes even to form, the main functional airframe. Throughout the 1920s and 1930s they fell out of use in favour of the low-drag cantilever construction, most aircraft bracing struts are principally loaded in compression, with wires taking the tension loads. Lift struts came into increasing use during the period and remain in use on smaller aircraft today where ultimate performance is not an issue. Typically they are applied to a monoplane and act in tension during flight. Struts have also widely used for purely structural reasons to attach engines, landing gear. The oil-sprung legs of retractable landing gear are still called Oleo struts, part of the functionality of the clavicle is to serve as a strut between the scapula and sternum, resisting forces that would otherwise bring the upper limb close to the thorax
9.
Axle
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An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating them, or fixed to the vehicle. In the former case, bearings or bushings are provided at the points where the axle is supported. In the latter case, a bearing or bushing sits inside a hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type axle is referred to as a spindle, on cars and trucks, several senses of the word axle occur in casual usage, referring to the shaft itself, its housing, or simply any transverse pair of wheels. Strictly speaking, a shaft which rotates with the wheel, being either bolted or splined in fixed relation to it, is called an axle or axle shaft, however, in looser usage an entire assembly including the surrounding axle housing is also called an axle. An even broader sense of the word refers to every pair of wheels on opposite sides of the vehicle, regardless of their mechanical connection to each other. Thus, transverse pairs of wheels in an independent suspension may be called an axle in some contexts, axles are an integral component of most practical wheeled vehicles. In a live-axle suspension system, the serve to transmit driving torque to the wheel, as well as to maintain the position of the wheels relative to each other. The axles in this system must also bear the weight of the vehicle plus any cargo. A non-driving axle, such as the front beam axle in heavy duty trucks and some 2-wheel drive light trucks and vans, will have no shaft, conversely, many front wheel drive cars have a solid rear beam axle. In other types of systems, the axles serve only to transmit driving torque to the wheels. This is typical of the independent suspension found on most newer cars and SUVs and these systems still have a differential, but it will not have attached axle housing tubes. It may be attached to the frame or body, or integral in a transaxle. The axle shafts then transmit driving torque to the wheels, like a full floating axle system, the drive shafts in a front wheel drive independent suspension system do not support any vehicle weight. A straight axle is a rigid shaft connecting a wheel on the left side of the vehicle to a wheel on the right side. The axis of rotation fixed by the axle is common to both wheels, such a design can keep the wheel positions steady under heavy stress, and can therefore support heavy loads. Straight axles are used on trains, for the axles of commercial trucks
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