|
Aviation Applied Technology Directorate
The United States Army Aviation Applied Technology Directorate (AATD) is a tenant activity located at Fort Eustis, Virginia. It is a directorate of the Aviation Development Directorate under the Aviation and Missile Research, Development, and Engineering Center (AMRDEC), a part of the Research, Development and Engineering Command (RDECOM). History The predecessor organization of AATD was established as the Transportation Corps Board on 16 December 1944 at Fort Monroe, Virginia. The original mission of the organization was research and development of all modes of transportation for the newly formed Transportation Corp. In 1946 it was transferred to thBrooklyn Army Base Brooklyn, New York. The Directorate has been located at Fort Eustis since 1950. The technology base pioneered for the UH-60 Black Hawk and the AH-64 Apache was established by AATD in the late 60s and 70s, and much of technological advancements have been developed and applied since then. These include elastomeric b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of the structure. Crashworthiness may be assessed either prospectively, using computer models (e.g., LS-DYNA, PAM-CRASH, MSC Dytran, MADYMO) or experiments, or retrospectively by analyzing crash outcomes. Several criteria are used to assess crashworthiness prospectively, including the deformation patterns of the vehicle structure, the acceleration experienced by the vehicle during an impact, and the probability of injury predicted by human body models. Injury probability is defined using criteria, which are mechanical parameters (e.g., force, acceleration, or deformation) that correlate with injury risk. A common injury criterion is the head impact criterion (HIC). Crashworthiness is as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army Aviation
The United States Army Aviation Branch is the administrative organization within the United States Army responsible for doctrine, manning and configuration for all army aviation units. After the United States Army Air Corps grew into the Army Air Forces and split into the new service, the United States Air Force, the Army was left with its sole fixed-wing aviation units flying Taylorcraft L-2 Grasshopper observation planes for artillery units. The Army would develop a new concept of aviation using the helicopter that would show promise during the Korean War and would revolutionize warfare during the Vietnam War. History Origins of Army Aviation Army Aviation traces its origins back to the American Civil War. Both Union and Confederate forces used hydrogen-filled balloons to direct artillery fire, marking the beginning of U.S. military aeronautics and of aerial support of Army ground forces. The Army also used balloons during the Spanish–American War and World War I, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Simulation
Military simulations, also known informally as war games, are simulations in which theories of warfare can be tested and refined without the need for actual hostilities. Military simulations are seen as a useful way to develop tactical, strategical and doctrinal solutions, but critics argue that the conclusions drawn from such models are inherently flawed, due to the approximate nature of the models used. Many professional analysts object to the term ''wargames'' as this is generally taken to be referring to the civilian hobby, thus the preference for the term ''simulation''. Simulations exist in many different forms, with varying degrees of realism. In recent times, the scope of simulations has widened to include not only military but also political and social factors, which are seen as inextricably entwined in a realistic warfare model. Whilst many governments make use of simulation, both individually and collaboratively, little is known about it outside professional circles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LHTEC T800
The LHTEC T800 is a turboshaft engine for rotary wing applications. It is produced by the LHTEC (Light Helicopter Turbine Engine Company), a joint venture between Rolls-Royce and Honeywell. The commercial and export version is the CTS800. The engine was primarily developed for the United States Army's cancelled RAH-66 Comanche armed reconnaissance helicopter, but has found use in other applications. Design and development The engine was originally developed for the United States Army's LHX armed reconnaissance helicopter competition, competing against the Avco/Pratt & Whitney T800. The LHTEC T800 was selected to power the LHX in 1988.Leyes, p. 213-216 The Boeing-Sikorsky team was selected to build the RAH-66 Comanche in 1991. A pair of T800-powered RAH-66 prototypes were constructed and underwent flight testing between 1996 and 2004. The LHX program was canceled in 2004, primarily due to cost overruns during its lengthy development, and the US Army's changing requirements. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric T700
The General Electric T700 and CT7 are a family of turboshaft and turboprop engines in the class. Design and development In 1967, General Electric began work on a new turboshaft engine demonstrator designated the "GE12" in response to US Army interest in a next-generation utility helicopter. The GE12 was designed and conceived by GE's Art Adamson and Art Adinolfi. In 1967, both GE and Pratt & Whitney were awarded contracts to work parallel with each other to design, fabricate, and test the technology. The Army effort led, in the 1970s, to development of the Sikorsky S-70 Black Hawk, powered by twin GE "T700" turboshafts, the production descendant of the GE12. The T700 was initially bench-tested in 1973, passed military qualification in 1976, and went into production in 1978. The initial "T700-GE-700" is an ungeared free-turbine turboshaft, with a five-stage axial / one-stage centrifugal mixed-flow compressor, featuring one-piece "blisk" axial stages, with the inlet guide vanes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire Strike Protection System
The wire strike protection system (WSPS) is a mechanical wire cutter designed to mitigate the risk of wire strikes whilst flying helicopters at low-level. History During the six-year period covering calendar years 1974 through 1979, wire strike accidents accounted for a significant share of United States Army Aviation peacetime mishaps, accounting for 8% of aircraft damage, 6% of aircraft-related injuries, and 16% of aircraft-related fatalities. Over a similar period covering the ten years between 1970 and 1979, 208 civil helicopters were involved in wire strike accidents. Of these, 88 were destroyed (42%) and 37 (11%) of the 331 people involved were killed. The most common cause of civil helicopter aerial accidents between 1975 and 1977 was striking wires and poles. Bristol Aerospace developed a WSPS qualified for the Bell OH-58 Kiowa under contract to the Canadian Armed Forces in May 1979. Nelson Chan is credited with inventing WSPS, according to the patents granted in 198 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airbag
An airbag is a vehicle occupant-restraint system using a bag designed to inflate extremely quickly, then quickly deflate during a collision. It consists of the airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. The purpose of the airbag is to provide a vehicle occupant with soft cushioning and restraint during a collision. It can reduce injuries between the flailing occupant and the interior of the vehicle. The airbag provides an energy-absorbing surface between the vehicle's occupants and a steering wheel, instrument panel, body pillar, headliner, and windshield. Modern vehicles may contain up to 10 airbag modules in various configurations, including: driver, passenger, side-curtain, seat-mounted, door-mounted, B and C-pillar mounted side-impact, knee bolster, inflatable seat belt, and pedestrian airbag modules. During a crash, the vehicle's crash sensors provide crucial information to the airbag electronic controller unit (ECU), including coll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Harness
A safety harness is a form of protective equipment designed to safeguard the user from injury or death from falling. The core item of a fall arrest system, the harness is usually fabricated from rope, braided wire cable, or synthetic webbing. It is attached securely to a stationary object directly by a locking device or indirectly via a rope, cable, or webbing and one or more locking devices. Some safety harnesses are used in combination with a shock-absorbing lanyard, which is used to regulate deceleration and thereby prevent a serious G-force injury when the end of the rope is reached. An unrelated use with a materially different arresting mechanism is bungee jumping. Though they share certain similar attributes, a safety harness is not to be confused with a climbing harness used for mountaineering, rock climbing, and climbing gyms. Specialized harnesses for animal rescue or transfer, as from a dock to a vessel, are also made. Standards In North America, safety harne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibration Control
In earthquake engineering, vibration control is a set of technical means aimed to mitigate seismic impacts in building and non-building structures. All seismic vibration control devices may be classified as ''passive'', ''active'' or ''hybrid'' where: * ''passive control devices'' have no feedback capability between them, structural elements and the ground; * ''active control devices'' incorporate real-time recording instrumentation on the ground integrated with earthquake input processing equipment and actuators within the structure; * ''hybrid control devices'' have combined features of active and passive control systems. When ground seismic waves reach up and start to penetrate a base of a building, their energy flow density, due to reflections, reduces dramatically: usually, up to 90%. However, the remaining portions of the incident waves during a major earthquake still bear a huge devastating potential. After the seismic waves enter a superstructure, there is a number of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-sealing Fuel Tank
A self-sealing fuel tank is a type of fuel tank, typically used in aircraft fuel tanks or fuel bladders, that prevents them from leaking fuel and igniting after being damaged. Typical self-sealing tanks have multiple layers of rubber and reinforcing fabric, one of vulcanized rubber, and one of untreated natural rubber, which can absorb fuel, swell, and expand when it comes into contact with the fuel. When a fuel tank is punctured, the fuel seeps into the layers, causing the untreated layer to swell and thus seal the puncture. A similar concept is also employed for making self-sealing run-flat tires. History World War I George J. Murdock applied for the patent "War Aeroplane Fuel Tanks" on February 7, 1917 but was temporarily blocked by an order of the Federal Trade Commission, on February 6, 1918, to keep any discussion or publication of the invention secret. The order was rescinded by the United States Patent Office on September 26, 1918 and Murdock was eventually granted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tail Rotor
The tail rotor is a smaller rotor mounted vertically or near-vertically at the tail of a traditional single-rotor helicopter, where it rotates to generate a propeller-like horizontal thrust in the same direction as the main rotor's rotation. The tail rotor's position and distance from the helicopter's center of mass allow it to develop enough thrust leverage to counter the reactional torque exerted on the fuselage by the spinning of the main rotor. Without the tail rotor or other anti-torque mechanisms (e.g. NOTAR), the helicopter would be constantly spinning in the opposite direction of the main rotor when flying. Tail rotors are simpler than main rotors since they require only collective changes in pitch to vary thrust. The pitch of the tail rotor blades is adjustable by the pilot via the anti-torque pedals, which also provide directional control by allowing the pilot to rotate the helicopter around its vertical axis. Its drive system consists of a shaft powered from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Crashworthiness")
