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Hybrid Airship
A hybrid airship is a powered aircraft that obtains some of its lift as a lighter-than-air (LTA) airship and some from lift (force), aerodynamic lift as a Aircraft#Heavier-than-air – aerodynes, heavier-than-air aerodyne. A ''dynastat'' is a hybrid airship with fixed wings and/or a lifting body and is typically intended for long-endurance flights. It requires forward flight to create the aerodynamic lift component. A ''rotastat'' is a hybrid airship with rotary wings and is typically intended for heavy lift applications. Its rotary wings can provide lift even when hovering or manoeuvring vertically, like a helicopter. No production designs have been built, but several crewed and uncrewed prototypes have flown. The term "hybrid airship" has also been used to describe an airship comprising a mix of rigid airship, rigid, semi-rigid airship, semi-rigid, and non-rigid airship, non-rigid construction. Features Conventional airships have low operating costs because they need no en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airlander - Flight Take-off Front (cropped)
The Hybrid Air Vehicles Airlander 10 (originally developed as the HAV 304; nicknamed "The Flying Bum") is a hybrid airship designed and built by British manufacturer Hybrid Air Vehicles (HAV). Comprising a helium airship with auxiliary wing and tail surfaces, it flies using both aerostatic and aerodynamic lift and is powered by four diesel engine-driven ducted propellers. The HAV 304 was originally built for the United States Army's Long Endurance Multi-intelligence Vehicle (LEMV) programme. Its maiden flight took place in 2012 at Lakehurst, New Jersey, in the US. In 2013, the LEMV project was cancelled by the US Army. HAV reacquired the airship and brought it back to Cardington Airfield in England. It was reassembled and modified for civilian use, and in this form was redesignated the Airlander 10. The modified aircraft completed design certification testing before being written off when it came loose from its moorings in a high wind on 18 November 2017 at Cardington Airfie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ducted Fan
In aeronautics, a ducted fan is a thrust-generating mechanical fan or Propeller (aeronautics), propeller mounted within a cylindrical wiktionary:duct, duct or shroud. Other terms include ducted propeller or shrouded propeller. When used in vertical takeoff and landing (VTOL) applications it is also known as a shrouded rotor.Kotwani, Kailash;Ducted Fan or Shrouded Rotor Aerodynamics and its Application in Miniature VTOL Aerial Vehicles, 2009. (retrieved 22 March 2022). Ducted fans are used for propulsion or direct lift in many types of vehicle including Airplane, airplanes, airships, hovercraft, and powered lift VTOL aircraft. The high-bypass turbofan engines used on many modern airliners is an example of a very successful and popular use of ducted fan design. The duct increases thrust (physics), thrust, in comparison to a similar-sized propeller in free air. Ducted fans are quieter, and offer good opportunities for thrust vectoring. The shroud offers good protection to ground per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Glider
An underwater glider is a type of autonomous underwater vehicle (AUV) that employs variable-buoyancy propulsion instead of traditional propellers or Underwater thruster, thrusters. It employs variable buoyancy in a similar way to a profiling float, but unlike a float, which can move only up and down, an underwater glider is fitted with hydrofoils (underwater wings) that allow it to Gliding flight, glide forward while descending through the water. At a certain depth, the glider switches to positive buoyancy to climb back up and forward, and the cycle is then repeated. While not as fast as conventional AUVs, gliders offer significantly greater range and endurance compared to traditional AUVs, extending ocean sampling missions from hours to weeks or months, and to thousands of kilometers of range. The typical up-and-down, Sawtooth wave, sawtooth-like profile followed by a glider can provide data on temporal and spatial scales unattainable by powered AUVs and much more costly to sampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glider (aircraft)
A glider is a fixed-wing aircraft that is supported in flight by the dynamic reaction of the air against its lifting surfaces, and whose free flight does not depend on an engine. Most gliders do not have an engine, although motor-gliders have small engines for extending their flight when necessary by sustaining the altitude (normally a sailplane relies on rising air to maintain altitude) with some being powerful enough to take off by self-launch. There are a wide variety of types differing in the construction of their wings, aerodynamic efficiency, location of the pilot, controls and intended purpose. Most exploit meteorological phenomena to maintain or gain height. Gliders are principally used for the air sports of gliding, hang gliding and paragliding. However some spacecraft have been designed to descend as gliders and in the past military gliders have been used in warfare. Some simple and familiar types of glider are toys such as paper planes and balsa wood glider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SkyHook JHL-40
The SkyHook JHL-40 was a proposed hybrid airship/helicopter. On July 9, 2008, Boeing announced that it had teamed up with SkyHook International, a Canada, Canadian company, to develop this aircraft. No further press releases appear after 2009 and Skyhook International has abandoned its domain name registration since 2010 as shown by the Internet Archive. According to company spokespeople, the aircraft would combine the best features of a blimp and a helicopter, and would be capable of carrying a 40 ton load up to without refueling. At long, it would classify as the largest helicopter in the world, and would be capable of flying up to without a load. The craft would use helium to provide enough lift to neutral buoyancy, carry its own weight, and would use four helicopter rotors to lift the load and to propel the aircraft. By using both helium and helicopter rotors, the aircraft can avoid having to jettison helium after unloading. In comparison, the CH-47 Chinook helicopter can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piasecki PA-97
The Piasecki PA-97 Helistat was an American experimental heavy-lift aircraft, built by Piasecki by fastening four H-34J helicopters to a framework beneath a helium-inflated blimp envelope. The sole prototype was lost during a test flight, killing a test pilot and injuring another four in the course of a single incident. Design and development Helistat design concept The Helistat concept was to augment the helicopters' dynamic lift with the static lift of an air buoyancy envelope. This would give greater maximum lift capability for heavy-lift work. At low weights (i.e. traveling to site without a payload) it would also free up the helicopters' rotor thrust for forward thrust, requiring less dynamic lift and lower fuel burn. To maintain coincidence of the dynamic and static lifts (otherwise the envelope would pitch as helicopter power increased), it is impractical to use a single helicopter rotor, so multiple rotors are arranged around the center of buoyancy of the envelope. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyrocopter
An autogyro (from Greek and , "self-turning"), gyroscope, gyrocopter or gyroplane, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. A gyroplane "means a rotorcraft whose rotors are not engine-driven, except for initial starting, but are made to rotate by action of the air when the rotorcraft is moving; and whose means of propulsion, consisting usually of conventional propellers, is independent of the rotor system." While similar to a helicopter rotor in appearance, the autogyro's unpowered rotor disc must have air flowing upward across it to make it rotate. Forward thrust is provided independently, by an engine-driven propeller. It was originally named the ''autogiro'' by its Spanish inventor and engineer, Juan de la Cierva, in his attempt to create an aircraft that could fly safely at low speeds. He first flew one on January 1923, at Cuatro Vientos Airport in Madrid. The aircraft resembled the fixed-wing aircraft of the day, with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zodiac Aerospace
Zodiac Aerospace was a French aerospace group, active from 1896 to 2018, that supplied systems and equipment for aircraft. In October 2018, it was acquired by French aerospace and defense company Safran. History Aeronautic foundations (1896–1933) The company was founded in 1896 as "Mallet, Mélandri et de Pitray" by Maurice Mallet and his associates. In the beginning, the company was involved in the production of hydrogen balloons for sport and tourism. In 1909, the company changed its name to "Zodiac." The company then experienced a boom fueled by the construction of airplanes and airships, especially for the Aérostation Maritime (Naval Balloon Command), and through its participation in the war effort. Until the 1930s, 63 airships would leave Zodiac's workshops. Marine activities (1934–1972) In 1934, the company created the first prototype inflatable boats, ancestors of the renowned "Zodiac," which would contribute to the development of the civil and military ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Étienne Oehmichen
Étienne Edmond Å’hmichen (; 15 October 1884, in Châlons-sur-Marne Châlons-en-Champagne – 10 July 1955, in Paris) was a French engineer and helicopter designer. Biography Å’hmichen studied at École Centrale Paris. He patented the first electric stroboscope in 1917, building at the same time a camera capable of shooting 1,000 frames per second. His first successful flight with a helicopter took place on 18 February 1921. On 11 November 1922, he first flew 'Oehmichen No.2', an improved helicopter featuring small vertically mounted rotors which rotated in the opposite direction from the large lifting rotors, probably creating the first reliable flying helicopter capable of carrying a person. This work later led to the development of the tail rotor. On 14 April 1924, he broke the existing record for helicopter flight with a flight of 360 m [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VTOL
A vertical take-off and landing (VTOL) aircraft is one that can takeoff and landing, take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wing aircraft and other hybrid aircraft with powered helicopter rotor, rotors such as cyclogyro, cyclogyros/cyclocopters and gyrodynes. Some VTOL aircraft can operate in other modes as well, such as CTOL (conventional take-off & landing), STOL (short take-off & landing), or STOVL (short take-off & vertical landing). Others, such as some helicopters, can only operate as VTOL, due to the aircraft lacking landing gear that can handle taxiing. VTOL is a subset of V/STOL (vertical or short take-off & landing). Some aerostat, lighter-than-air aircraft also qualify as VTOL aircraft, as they can hover, takeoff and land with vertical approach/departure profiles. Electric vertical takeoff and landing aircraft, or eVTOLs, are being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STOL
A short takeoff and landing (STOL) aircraft is a fixed-wing aircraft that can takeoff/land on short runways. Many STOL-designed aircraft can operate on airstrips with harsh conditions (such as high altitude or ice). STOL aircraft, including those used in scheduled passenger airline operations, can be operated from STOLport airfields that feature short runways. Design STOL aircraft come in configurations such as bush planes, autogyros, and Conventional landing gear, taildraggers, and those such as the de Havilland Canada Dash-7 that are designed for use on conventional airstrips. The PAC P-750 XSTOL, the Daher Kodiak, the de Havilland Canada DHC-6 Twin Otter and the Wren 460 have STOL capability, needing a short ground roll to get airborne, but are capable of a near-zero ground roll when landing. For any plane, the required runway length is a function of the square of the stall speed (minimum flying speed), and much design effort is spent on minimizing this number. For take ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lift-induced Drag
Lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, in aerodynamics, is an aerodynamic drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings or a lifting body redirecting air to cause lift and also in cars with airfoil wings that redirect air to cause a downforce. It is symbolized as D_\text, and the ''lift-induced drag coefficient'' as C_. For a constant amount of lift, induced drag can be reduced by increasing airspeed. A counter-intuitive effect of this is that, up to the speed-for-minimum-drag, aircraft need less power to fly faster. Induced drag is also reduced when the wingspan is higher, or for wings with wingtip devices. Explanation The total aerodynamic force acting on a body is usually thought of as having two components, lift and drag. By definition, the component of force parallel to the oncoming flow is called drag; and the component perpendicular to the oncomin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
