|
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 mai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tail Rotor S-61
The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds. While tails are primarily a feature of vertebrates, some invertebrates including scorpions and springtails, as well as snails and slugs, have tail-like appendages that are sometimes referred to as tails. Tailed objects are sometimes referred to as "caudate" and the part of the body associated with or proximal to the tail are given the adjective "caudal". Function Animal tails are used in a variety of ways. They provide a source of locomotion for fish and some other forms of marine life. Many land animals use their tails to brush away flies and other biting insects. Most canines use their tails to comunicate mood and intention . Some species, including cats and kangaroos, use their tails for balance; and some, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drive Shaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power (physics), power and torque and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them. As torque carriers, drive shafts are subject to torsion (mechanics), torsion and shear stress, equivalent to the difference between the input torque and the load. They must therefore be strong enough to bear the stress, while avoiding too much additional weight as that would in turn increase their inertia. To allow for variations in the alignment and distance between the driving and driven components, drive shafts frequently incorporate one or more universal joints, jaw couplings, or rag joints, and sometimes a Rotating spline, splined joint or prismatic joint. History The term ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescent Penetrant Inspection
Fluorescent penetrant inspection (FPI) is a type of dye penetrant inspection in which a fluorescent dye is applied to the surface of a non-porous material in order to detect defects that may compromise the integrity or quality of the part in question. FPI is noted for its low cost and simple process, and is used widely in a variety of industries. Materials There are many types of dye used in penetrant inspections. FPI operations use a dye much more sensitive to smaller flaws than penetrants used in other DPI procedures. This is because of the nature of the fluorescent penetrant that is applied. With its brilliant yellow glow caused by its reaction with ultraviolet radiation, FPI dye sharply contrasts with the dark background. A vivid reference to even minute flaws is easily observed by a skilled inspector. Because of its sensitivity to such small defects, FPI is ideal for most metals which tend to have small, tight pores and smooth surfaces. Defects can vary but are typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell 206B JetRanger II AN1761224
A bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an internal "clapper" or "uvula", an external hammer, or—in small bells—by a small loose sphere enclosed within the body of the bell (jingle bell). Bells are usually cast from bell metal (a type of bronze) for its resonant properties, but can also be made from other hard materials. This depends on the function. Some small bells such as ornamental bells or cowbells can be made from cast or pressed metal, glass or ceramic, but large bells such as a church, clock and tower bells are normally cast from bell metal. Bells intended to be heard over a wide area can range from a single bell hung in a turret or bell-gable, to a musical ensemble such as an English ring of bells, a carillon or a Russian zvon which are tuned to a common scale and installe ... [...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 |
Sprag Clutch
A sprag clutch is a one-way freewheel clutch. It resembles a roller bearing but, instead of cylindrical rollers, non-revolving asymmetric figure-eight shaped sprags, or other elements allowing single direction rotation, are used. When the unit rotates in one direction the rollers slip or free-wheel, but when a torque is applied in the opposite direction, the sprags tilt slightly, producing a wedging action and binding because of friction. Applications Automatic transmissions A sprag clutch is used in some automatic transmissions as a method of allowing the transmission to change gears smoothly under load. Various models of General Motors' Turbo-Hydramatic transmission have used this system as well as many transmissions from Ford, such as the Ford C6 transmission. A sprag clutch is used in most older automatic transmissions and some newer ones for shifts which require the synchronized engagement of one clutch with the disengagement of another. Using an overrunning clutch instea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls that enable the pilot to fly the aircraft. In most airliners, a door separates the cockpit from the aircraft cabin. After the September 11 attacks, September 11, 2001 attacks, all major airlines Airport_security_repercussions_due_to_the_September_11_attacks#Improved_security_on_aircraft, fortified their cockpits against access by aircraft hijacking, hijackers. Etymology The word cockpit seems to have been cockpit (sailing), used as a nautical term in the 17th century, without reference to cock fighting. It referred to an area in the rear of a ship where the cockswain's station was located, the cockswain being the pilot of a smaller "boat" that could be dispatched from the ship to board another ship or to bring people ashore. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Fiber Composite
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light fiber-reinforced plastics that contain carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications. The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester, or nylon, are sometimes used. The properties of the final CFRP product can be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity towards ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Material
A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Typical engineered composite materials include: *Reinforced concrete and masonry *Composite wood such as plywood *Reinforced plastics, such as fibre-reinforced polymer or fiberglass *Ceramic matrix composites ( composite ceramic and metal matrices) *Metal matrix composites *and other advanced composite materials There are various reasons where new material can be favoured. Typical examples include materials which are less expensive, lighter, stronger or more durable when compared with commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Control
A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed. The fundamentals of aircraft controls are explained in flight dynamics. This article centers on the operating mechanisms of the flight controls. The basic system in use on aircraft first appeared in a readily recognizable form as early as April 1908, on Louis Blériot's Blériot VIII pioneer-era monoplane design. Cockpit controls Primary controls Generally, the primary cockpit flight controls are arranged as follows:Langewiesche, WolfgangStick and Rudder: An Explanation of the Art of Flying McGraw-Hill Professional, 1990, , . * a control yoke (also known as a control column), centre stick or side-stick (the latter two also colloquially known as a control or j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airspeed
In aviation, airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: * Indicated airspeed ("IAS"), what is read on an airspeed gauge connected to a Pitot-static system; * Calibrated airspeed ("CAS"), indicated airspeed adjusted for pitot system position and installation error; * Equivalent airspeed ("EAS"), calibrated airspeed adjusted for compressibility effects; * True airspeed ("TAS"), equivalent airspeed adjusted for air density, and is also the speed of the aircraft through the air in which it is flying. Calibrated airspeed is typically within a few knots of indicated airspeed, while equivalent airspeed decreases slightly from CAS as aircraft altitude increases or at high speeds. With EAS constant, true airspeed increases as aircraft altitude increases. This is because air density decreases with higher altitude. The measurement and indication of airspeed is ordinarily accomplished on board an aircraft by an air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
