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Bell ARH-70
The Bell ARH-70 Arapaho was an American four-bladed, single-engine, light military helicopter designed for the United States Army's Armed Reconnaissance Helicopter (ARH) program. With a crew of two and optimized for urban combat, the ARH-70 was slated to replace the Army's aging OH-58D Kiowa Warrior. Excessive delays and growth in program costs forced its cancellation on 16 October 2008, when the Department of Defense failed to certify the program to Congress. The ARH-70 was touted as having been built with off-the-shelf technology, the airframe being based on the Bell 407. Development Background and Armed Reconnaissance Helicopter competition The RAH-66 Comanche helicopter program was canceled by the U.S. Army on 23 February 2004. The cancellation was a result of a six-month study which recommended canceling the program before the Comanche reached production, after 20 years and development costs of over US$6.9 billion. The study estimated that the Army would save US$14 billio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WikiProject Aircraft
A WikiProject, or Wikiproject, is a Wikimedia movement affinity group for contributors with shared goals. WikiProjects are prevalent within the largest wiki, Wikipedia, and exist to varying degrees within sister projects such as Wiktionary, Wikiquote, Wikidata, and Wikisource. They also exist in different languages, and translation of articles is a form of their collaboration. During the COVID-19 pandemic, CBS News noted the role of Wikipedia's WikiProject Medicine in maintaining the accuracy of articles related to the disease. Another WikiProject that has drawn attention is WikiProject Women Scientists, which was profiled by '' Smithsonian'' for its efforts to improve coverage of women scientists which the profile noted had "helped increase the number of female scientists on Wikipedia from around 1,600 to over 5,000". On Wikipedia Some Wikipedia WikiProjects are substantial enough to engage in cooperative activities with outside organizations relevant to the field at issue. For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell 430
The Bell 430 is an American/Canadian twin-engine light-medium helicopter built by Bell Helicopter. It is a stretched and more powerful development of the Bell 230, which, in turn, was based on the earlier Bell 222. Development While developing the reengined Model 222 as the 230, Bell began preliminary design work on a stretched derivative with a four-bladed main rotor in 1991. The Bell 430 was formally launched in February 1992, with two prototypes modified from Bell 230s. The first of these flew in its new configuration on October 25, 1994, and the second prototype, featuring the full 430 avionics suite, first flew on December 19, 1994.Frawley, Gerard: ''The International Directory of Civil Aircraft, 2003-2004'', p. 46. Aerospace Publications Pty. Ltd., 2003. . Production of the Bell 230 ended in August 1995, and 430 production began. The first 430 production aircraft was completed later that year. Canadian certification was awarded on February 23, 1996. Deliveries began in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MD Helicopters MH-6 Little Bird
The Boeing MH-6M Little Bird (nicknamed the Killer Egg) and its attack variant, the AH-6, are light helicopters used for special operations in the United States Army. Originally based on a modified OH-6A, it was later based on the MD 500E, with a single five-bladed main rotor. The newest version, the MH-6M, is based on the MD 530F and has a single, six-bladed main rotor and four-bladed tail rotor. Development The OH-6 was started in 1960, when the U.S. Army issued Technical Specification 153 for a Light Observation Helicopter (LOH) that could perform personnel transport, escort and attack missions, casualty evacuation, and observation. Twelve companies took part in the competition and Hughes Tool Company's Aircraft Division submitted the Model 369. Two designs, those submitted by Fairchild-Hiller and Bell, were selected as finalists by the Army-Navy design competition board, but the Army later included the helicopter from Hughes as well. The first Model 369 prototype fle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell OH-58 Kiowa
The Bell OH-58 Kiowa is a family of single-engine single-rotor military helicopters used for observation, utility, and direct fire support. It was produced by the American manufacturer Bell Helicopter and is closely related to the Model 206A JetRanger civilian helicopter. The OH-58 was originally developed during the early 1960s as the ''D-250'' for the Light Observation Helicopter (LOH). While the rival Hughes OH-6 Cayuse was picked over Bell's submission in May 1965, the company refined its design to create the Model 206A, a variant of which it successfully submitted to the reopened LOH competition two years later. The initial model, designated by the service as the ''OH-58A'', was introduced in May 1969. Successive models would follow, often with uprated engines, enhanced protection systems, and other improvements, cumulating in the ''OH-58F''. Additional improvements, such as the ''OH-58X'', were proposed but ultimately not pursued. During the 1970s, the US Army became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydra 70
The Hydra 70 rocket is a diameter fin-stabilized unguided rocket used primarily in the air-to-ground role. It can be equipped with a variety of warheads, and in more recent versions, guidance systems for point attacks. The Hydra is widely used by US and allied forces, competing with the Canadian CRV-7, with which it is physically interchangeable. Overview The Hydra 70 is derived from the diameter Mk 4/Mk 40 Folding-Fin Aerial Rocket developed by the United States Navy for use as a free-flight aerial rocket in the late 1940s. The Mk 40 was used during the Korean and Vietnam wars to provide close air support to ground forces from about 20 different firing platforms, both fixed-wing and armed helicopters. The main change made to produce the Hydra was the Mk. 66 motor which uses a new propellant that offers considerably more thrust, (Mod 2/3) (Mod 4). The fins of the Mk 40 flipped forward from the rear when the rocket left the launching tube, but in the Hydra they are curved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gatling Gun
The Gatling gun is a rapid-firing multiple-barrel firearm invented in 1861 by Richard Jordan Gatling. It is an early machine gun and a forerunner of the modern electric motor-driven rotary cannon. The Gatling gun's operation centered on a cyclic multi-barrel design which facilitated cooling and synchronized the firing-reloading sequence. As the handwheel is cranked, the barrels rotate and each barrel sequentially loads a single cartridge from a top-mounted magazine, fires off the shot when it reaches a set position (usually at 4 o'clock), then ejects the spent casing out of the left side at the bottom, after which the barrel is empty and allowed to cool until rotated back to the top position and gravity-fed another new round. This configuration eliminated the need for a single reciprocating bolt design and allowed higher rates of fire to be achieved without the barrels overheating quickly. One of the best-known early rapid-fire firearms, the Gatling gun saw occasional use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GAU-19
The GAU-19/A (GECAL 50) is an electrically driven, three-barrel rotary heavy machine gun that fires the .50 BMG (12.7×99mm) cartridge. Technical specifications The GAU-19/A is designed to accept standard NATO .50 caliber M9-linked ammunition. The rate of fire is selectable to be either 1,000 or 2,000 rounds per minute. The Humvee armament kit version fires at 1,300 rounds per minute. The average recoil force when firing is 1.7 kN, 2.2 kN or 2.8 kN depending on firing rate. In January 2012, General Dynamics announced they would be delivering a new version designated GAU-19/B. It provides the same firepower in a lighter platform, weighing and optimized for a firing rate of 1,300 rounds per minute and an average recoil force of 2.5 kN.GD delivers GAU-19/B - General Dynamics Both variants can be con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turboshaft
A turboshaft engine is a form of gas turbine that is optimized to produce shaftpower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the exhaust and convert it into output shaft power. They are even more similar to turboprops, with only minor differences, and a single engine is often sold in both forms. Turboshaft engines are commonly used in applications that require a sustained high power output, high reliability, small size, and light weight. These include helicopters, auxiliary power units, boats and ships, tanks, hovercraft, and stationary equipment. Overview A turboshaft engine may be made up of two major parts assemblies: the 'gas generator' and the 'power section'. The gas generator consists of the compressor, combustion chambers with ignitors and fuel nozzles, and one or more stages of turbine. The power section consists of additional stages of turbines, a gear reduction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Department Of Defense
The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national security and the United States Armed Forces. The DoD is the largest employer in the world, with over 1.34 million active-duty service members (soldiers, marines, sailors, airmen, and guardians) as of June 2022. The DoD also maintains over 778,000 National Guard and reservists, and over 747,000 civilians bringing the total to over 2.87 million employees. Headquartered at the Pentagon in Arlington, Virginia, just outside Washington, D.C., the DoD's stated mission is to provide "the military forces needed to deter war and ensure our nation's security". The Department of Defense is headed by the secretary of defense, a cabinet-level head who reports directly to the president of the United States. Beneath the Department of Defense are th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nunn–McCurdy Amendment
The Nunn–McCurdy Amendment or Nunn–McCurdy Provision, introduced by Senator Sam Nunn and Congressman Dave McCurdy in the United States 1982 Defense Authorization Act and made permanent in 1983, is designed to curtail cost growth in American weapons procurement programs. It requires notification to the United States Congress if the cost per unit goes more than 25% beyond what was originally estimated and calls for the termination of programs with total cost growth greater than 50%, unless the Secretary of Defense submits a detailed explanation certifying: # the program is essential to national security, that no suitable alternative of lesser cost is available; # new estimates of total program costs are reasonable; and # management structure is (or has been made) adequate to control costs. Congress normally regards the explanations from the Secretary of Defense as acceptable. It is unusual for a program to be cancelled as a result of notification, but it has led to many change ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Textron
Textron Inc. is an American industrial conglomerate based in Providence, Rhode Island. Textron's subsidiaries include Arctic Cat, Bell Textron, Textron Aviation (which itself includes the Beechcraft, and Cessna brands), and Lycoming Engines. It was founded by Royal Little in 1923 as the Special Yarns Company. In 2020, Textron employed over 33,000 people in 25 different countries. The company ranked 265th on the 2021 ''Fortune'' 500 of the largest United States corporations by revenue. History Early history Textron started as a textile company in 1923, when 27-year-old Royal Little founded the Special Yarns Corporation in Boston, Massachusetts. The company manufactured synthetic yarns, a niche product at the time. By the start of World War II, the company was known as Atlantic Rayon Corporation and manufactured parachutes. As war production wound down, the company started making civilian products as well and was renamed Textron: “Tex" for "textiles" and "tron" from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autorotation (helicopter)
Autorotation is a state of flight in which the main rotor system of a helicopter or other rotary-wing aircraft turns by the action of air moving up through the rotor, as with an autogyro, rather than engine power driving the rotor. Bensen, Igor.How they fly – Bensen explains all" ''Gyrocopters UK''. Accessed: 10 April 2014. Quote: "air.. (is) deflected downward"Charnov, Bruce HCierva, Pitcairn and the Legacy of Rotary-Wing Flight ''Hofstra University''. Accessed: 22 November 2011. The term ''autorotation'' dates to a period of early helicopter development between 1915 and 1920, and refers to the rotors turning without the engine."Autorotation", ''Dictionary.com Unabridged (v 1.1)''. Random House, Inc. 17 April 2007 It is analogous to the |
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