|
Tiltrotor
A tiltrotor is an aircraft that generates lift (force), lift and thrust, propulsion by way of one or more powered Helicopter rotor, rotors (sometimes called ''proprotors'') mounted on rotating shaft (mechanical engineering), shafts or nacelles usually at the ends of a fixed wing. Almost all tiltrotors use a transverse rotor design, with a few exceptions that use other multirotor layouts. Tiltrotor design combines the VTOL capability of a helicopter with the speed and range (aircraft), range of a conventional fixed-wing aircraft. For vertical flight, the rotors are angled so the plane of rotation is horizontal, generating lift the way a normal helicopter rotor does. As the aircraft gains speed, the rotors are progressively tilted forward, with the plane of rotation eventually becoming vertical. In this mode the rotors provide thrust as a propeller (aircraft), propeller, and the airfoil of the fixed wings takes over providing the lift via the forward motion of the entire aircra ... [...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] |
XV-15 N703NA USCG
The Bell XV-15 is an American tiltrotor VTOL aircraft. It was the second successful experimental tiltrotor aircraft and the first to demonstrate the concept's high speed performance relative to conventional helicopters. Development Early VTOL rotor aircraft The idea of building VTOL aircraft using helicopter-like rotors at the wingtips originated in the 1930s. The first design resembling modern tiltrotors was patented by George Lehberger in May 1930, but he did not develop the concept further. In World War II, a Germany, German prototype called the Focke-Achgelis Fa 269 was developed starting in 1942, but it never flew. Two prototypes that made it to flight were the one-seat Transcendental Model 1-G and two-seat Transcendental Model 2, both powered by single reciprocating engines. Development started on the Model 1-G in 1947, and it flew in 1954. The Model 1-G flew until a crash in Chesapeake Bay on 20 July 1955, destroying the prototype aircraft but not seriously injuring the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiltwing
A tiltwing aircraft features a wing that is horizontal for conventional forward flight and rotates up for vertical takeoff and landing. It is similar to the tiltrotor design where only the propeller and engine rotate. Tiltwing aircraft are typically fully capable of VTOL operations.Markman, Steve and Bill Holder. "Tilt-Wing VTOL Systems". ''Straight Up: A History of Vertical Flight''. Schiffer Publishing, 2000. . The tiltwing design offers certain advantages in vertical flight relative to a tiltrotor. Because the slipstream from the rotor strikes the wing on its smallest dimension, the tiltwing is able to apply more of its engine power to lifting the aircraft. For comparison, the V-22 Osprey tiltrotor loses about 10% of its thrust to interference from the wings. Another advantage of tiltwing aircraft is the ease of transition between VTOL and horizontal flight modes. A tiltrotor must first fly forwards like a helicopter, building airspeed until wing lift is sufficient to allo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Rotor
On a helicopter, the main rotor or rotor system is the combination of several rotary wings (rotor blades) with a control system, that generates the aerodynamic lift (force), lift force that supports the weight of the helicopter, and the thrust that counteracts aerodynamic drag in forward flight. Each main rotor is mounted on a vertical mast over the top of the helicopter, as opposed to a helicopter tail rotor, which connects through a combination of drive shaft(s) and gearboxes along the tail boom. The blade pitch is typically controlled by the pilot using the helicopter flight controls. Helicopters are one example of rotary-wing aircraft (rotorcraft). The name is derived from the Greek words ''helix'', helik-, meaning spiral; and ''pteron'' meaning wing. Design principles Overview The helicopter rotor is powered by the engine, through the transmission, to the rotating mast. The mast is a cylindrical metal shaft that extends upward from—and is driven by—the transmission. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proprotor
A proprotor is a spinning airfoil that function as both an airplane-style propeller and a helicopter-style rotor. Several proprotor-equipped convertiplanes, such as the Bell Boeing V-22 Osprey tiltrotor, are capable of switching back and forth between flying akin to both helicopters and fixed-wing aircraft. Accordingly this type of airfoil has been predominantly applied to vertical takeoff and landing (VTOL) aircraft. The dual-role airfoil is accomplished by one of several design approaches: :*changing the angle of attack of the wing that the proprotor is attached to, from approximately zero degrees to around ninety degrees: a tiltwing aircraft, :*changing the angle of attack of only the rotor hub, and possibly the engine that drives it, as on a tiltrotor, :*changing the angle of attack of the entire aircraft, as on a tailsitter, which launches and lands on its tail. Application details On several aerial vehicles such as the AgustaWestland AW609 and V-22 Osprey, a pair of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter
A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing (STOL) or short take-off and vertical landing (STOVL) aircraft cannot perform without a runway. The Focke-Wulf Fw 61 was the first successful, practical, and fully controllable helicopter in 1936, while in 1942, the Sikorsky R-4 became the first helicopter to reach full-scale mass production, production. Starting in 1939 and through 1943, Igor Sikorsky worked on the development of the Vought-Sikorsky VS-300, VS-300, which over four iterations, became the basis for modern helicopters with a single main rotor and a single tail rotor. Although most earlier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft
An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, in a few cases, direct Powered lift, downward thrust from its engines. Common examples of aircraft include airplanes, rotorcraft (including helicopters), airships (including blimps), Glider (aircraft), gliders, Powered paragliding, paramotors, and hot air balloons. Part 1 (Definitions and Abbreviations) of Subchapter A of Chapter I of Title 14 of the U. S. Code of Federal Regulations states that aircraft "means a device that is used or intended to be used for flight in the air." The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called ''aeronautics.'' Aircrew, Crewed aircraft are flown by an onboard Aircraft pilot, pilot, whereas unmanned aerial vehicles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maximum Takeoff Weight
The maximum takeoff weight (MTOW) or maximum gross takeoff weight (MGTOW) or maximum takeoff mass (MTOM) of an aircraft, also known as the maximum structural takeoff weight or maximum structural takeoff mass, is the maximum weight at which the pilot is allowed to attempt to take off, due to structural or other limits. The analogous term for rockets is gross lift-off mass, or GLOW. MTOW is usually specified in units of kilograms or pounds. MTOW is the heaviest weight at which the aircraft has been shown to meet all the airworthiness requirements applicable to it. It refers to the maximum permissible aircraft weight at the start of the takeoff run. MTOW of an aircraft is fixed and does not vary with altitude, air temperature, or the length of the runway to be used for takeoff or landing. Maximum permissible takeoff weight or "regulated takeoff weight", varies according to flap setting, altitude, air temperature, length of runway and other factors. It is different from one takeof ... [...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] |
Original Tiltrotor Patent
Originality is the aspect of created or invented works that distinguish them from reproductions, clones, forgeries, or substantially derivative works. The modern idea of originality is according to some scholars tied to Romanticism, by a notion that is often called romantic originality.Smith (1924)Waterhouse (1926)Macfarlane (2007) The validity of "originality" as an operational concept has been questioned. For example, there is no clear boundary between "derivative" and "inspired by" or "in the tradition of." The concept of originality is both culturally and historically contingent. For example, unattributed reiteration of a published text in one culture might be considered plagiarism but in another culture might be regarded as a convention of veneration. At the time of Shakespeare, it was more common to appreciate the similarity with an admired classical work, and Shakespeare himself avoided "unnecessary invention".Royal Shakespeare Company (2007) ''The RSC Shakespeare - Wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STOVL
A short take-off and vertical landing aircraft (STOVL aircraft) is a fixed-wing aircraft that is able to take off from a short runway (or take off vertically if it does not have a heavy payload) and land vertically (i.e. with no runway). The formal NATO definition (since 1991) is: On aircraft carriers, non-catapult-assisted fixed-wing short takeoffs are accomplished with the use of thrust vectoring, which may also be used in conjunction with a runway " ski-jump". There are 14 aircraft carriers that operate these STOVL aircraft: United States (9), United Kingdom (2), Italy (2), and Spain (1). Use of STOVL tends to allow aircraft to carry a larger payload compared to vertical take-off and landing (VTOL), while still only requiring a short runway. The most famous examples are the Hawker Siddeley Harrier and the BAe Sea Harrier. Although technically a V/STOL aircraft, they are operationally STOVL aircraft due to the extra weight carried at take-off for fuel and armaments. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
