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Collective Pitch
A helicopter pilot manipulates the helicopter flight controls to achieve and maintain controlled aerodynamic flight. Changes to the aircraft flight control system transmit mechanically to the rotor, producing aerodynamic effects on the rotor blades that make the helicopter move in a deliberate way. To tilt forward and back (pitch) or sideways (roll) requires that the controls alter the angle of attack of the main rotor blades ''cyclically'' during rotation, creating differing amounts of lift (force) at different points in the cycle. To increase or decrease overall lift requires that the controls alter the angle of attack for all blades ''collectively'' by equal amounts at the same time, resulting in ascent, descent, acceleration and deceleration. A typical helicopter has three flight control inputs—the cyclic stick, the collective lever, and the anti-torque pedals. Depending on the complexity of the helicopter, the cyclic and collective may be linked together by a ''mixing uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Controls Diagram
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to 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 STOL (Short TakeOff and Landing) or STOVL (Short TakeOff and Vertical Landing) aircraft cannot perform without a runway. In 1942, the Sikorsky R-4 became the first helicopter to reach full-scale production.Munson 1968.Hirschberg, Michael J. and David K. Dailey"Sikorsky". ''US and Russian Helicopter Development in the 20th Century'', American Helicopter Society, International. 7 July 2000. Although most earlier designs used more than one main rotor, the configuration of a single main rotor accompanied by a vertical anti-torque tail rotor (i.e. unicopter, not to be confused with the single-blade monocopter) has become the most common he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston Engine
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.''Thermodynamics: An Engineering Approach'' by Yunus A. Cengal and Michael A. Boles Common features in all types There may be one or more pistons. Each piston is inside a cylinder, into which a gas is intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tandem Rotors
Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction. The original use of the term in English was in ''tandem harness'', which is used for two or more draft horses, or other draft animals, harnessed in a single line one behind another, as opposed to a pair, harnessed side by side, or a team of several pairs. The tandem harness allows additional animals to provide pulling power for a vehicle designed for a single animal. The English word ''tandem'' derives from the Latin adverb , meaning ''at length'' or ''finally''. It is a word play, using the Latin phrase (referring to time, not position) for English "at length, lengthwise". Tandem bicycles are named for their tandem seating, a more common arrangement than side-by-side "sociable" seating. ''Tandem'' can also be used more generally to refer to any group of persons or objects working together, not necessarily in line. Automob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contra-rotating
Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby parts of a mechanism rotate in opposite directions about a common axis, usually to minimise the effect of torque. Examples include some aircraft propellers, resulting in the maximum power of a single piston or turboprop engine to drive two propellers in opposite rotation. Contra-rotating propellers are also common in some marine transmission systems, in particular for large speed boats with planing hulls. Two propellers are arranged one behind the other, and power is transferred from the engine via planetary gear transmission. The configuration can also be used in helicopter designs termed coaxial rotors, where similar issues and principles of torque apply. Contra-rotating propellers should not be confused with counter-rotating propellers, a term which describes non-coaxial propellers on separate shafts; one turning clockwise and the other counter-clockwise. Tandem-rotor helicopters such as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kamov Ka-50
The Kamov Ka-50 "Black Shark" (russian: Чёрная акула, translit=Chyornaya akula, English: kitefin shark, NATO reporting name: Hokum A) is a Soviet/Russian single-seat attack helicopter with the distinctive coaxial rotor system of the Kamov design bureau. It was designed in the 1980s and adopted for service in the Russian army in 1995. It is manufactured by the Progress company in Arsenyev. It is used as a heavily armed scout helicopter. It has a rescue ejection system, rare for helicopters. During the late 1990s, Kamov and Israel Aerospace Industries developed a tandem-seat cockpit version, the Kamov Ka-50-2 "Erdogan" (russian: link=no, Эрдоган, tr, Erdoğan), to compete in Turkey's attack helicopter competition. Kamov also designed another two-seat variant, the Kamov Ka-52 "Alligator" (russian: link=no, Аллигатор, NATO reporting name: Hokum B). Development The Ka-50 is the production version of the V-80Sh-1 prototype. Production of the attack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coaxial Rotors
Coaxial rotors or coax rotors are a pair of helicopter rotors mounted one above the other on concentric shafts, with the same axis of rotation, but turning in opposite directions (contra-rotating). This rotor configuration is a feature of helicopters produced by the Russian Kamov helicopter design bureau. History The idea of coaxial rotors originates with Mikhail Lomonosov. He had developed a small helicopter model with coaxial rotors in July 1754 and demonstrated it to the Russian Academy of Sciences. In 1859, the British Patent Office awarded the first helicopter patent to Henry Bright for his coaxial design. From this point, coaxial helicopters developed into fully operational machines as we know them today. Two pioneering helicopters, the Corradino D'Ascanio-built "D'AT3" of 1930, and the generally more successful French mid-1930s ''Gyroplane Laboratoire'', both used coaxial rotor systems for flight. Design considerations Having two coaxial sets of rotors provides sym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turn And Bank Indicator
In aviation, the turn and slip indicator (T/S, a.k.a. turn and bank indicator) and the turn coordinator (TC) variant are essentially two aircraft flight instruments in one device. One indicates the rate of turn, or the rate of change in the aircraft's heading; the other part indicates whether the aircraft is in coordinated flight, showing the slip or skid of the turn. The slip indicator is actually an inclinometer that at rest displays the angle of the aircraft's transverse axis with respect to horizontal, and in motion displays this angle as modified by the acceleration of the aircraft. The most commonly used units are degrees per second (deg/s) or minutes per turn (min/tr). Name The turn and slip indicator can be referred to as the turn and bank indicator, although the instrument does not respond directly to bank angle. Neither does the turn coordinator, but it does respond to roll rate, which enables it to respond more quickly to the start of a turn. Operation Turn indicato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Course (navigation)
In navigation, the course of a watercraft or aircraft is the cardinal direction in which the craft is to be steered. The course is to be distinguished from the ''heading'', which is the direction where the watercraft's bow or the aircraft's nose is pointed. Course, track, route and heading The path that a vessel follows over the ground is called a ''ground track'', ''course made good'' or ''course over the ground''. For an aircraft it is simply its ''track''. The intended track is a ''route''. For ships and aircraft, routes are typically straight-line segments between waypoints. A navigator determines the ''bearing'' (the compass direction from the craft's current position) of the next waypoint. Because water currents or wind can cause a craft to drift off course, a navigator sets a ''course to steer'' that compensates for drift. The helmsman or pilot points the craft on a ''heading'' that corresponds to the course to steer. If the predicted drift is correct, then the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sideslip Angle
A slip is an aerodynamic state where an aircraft is moving ''somewhat'' sideways as well as forward relative to the oncoming airflow or relative wind. In other words, for a conventional aircraft, the nose will be pointing in the opposite direction to the bank of the wing(s). The aircraft is not in coordinated flight and therefore is flying inefficiently. Background Flying in a slip is aerodynamically inefficient, since the lift-to-drag ratio is reduced. More drag is at play consuming energy but not producing lift. Inexperienced or inattentive pilots will often enter slips unintentionally during turns by failing to coordinate the aircraft with the rudder. Airplanes can readily enter into a slip climbing out from take-off on a windy day. If left unchecked, climb performance will suffer. This is especially dangerous if there are nearby obstructions under the climb path and the aircraft is underpowered or heavily loaded. A slip can also be a ''piloting maneuver'' where the pilot del ... [...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 mai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swashplate (helicopter)
A swashplate is a mechanical device that translates input via the helicopter flight controls into motion of the main rotor blades. Because the main rotor blades are spinning, the swashplate is used to transmit three of the pilot's commands from the non-rotating fuselage to the rotating rotor hub and mainblades. Assembly The swashplate consists of two main parts: a stationary swashplate and a rotating swashplate. The stationary (outer) swashplate is mounted on the main rotor mast and is connected to the cyclic and collective controls by a series of pushrods. It is able to tilt in all directions and move vertically. The rotating (inner) swashplate is mounted to the stationary swashplate by means of a bearing and is allowed to rotate with the main rotor mast. An anti-rotation link prevents the inner swash from rotating independently of the blades, which would apply torque to the actuators. The outer swashplate typically has an anti-rotation slider as well to prevent it from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOTAR
NOTAR ("no tail rotor") is a helicopter system which avoids the use of a tail rotor. It was developed by McDonnell Douglas Helicopter Systems (through their acquisition of Hughes Helicopters). The system uses a fan inside the tail boom to build a high volume of low-pressure air, which exits through two slots and creates a boundary layer flow of air along the tailboom utilizing the Coandă effect. The boundary layer changes the direction of airflow around the tailboom, creating thrust opposite the motion imparted to the fuselage by the torque effect of the main rotor. Directional yaw control is gained through a vented, rotating drum at the end of the tailboom, called the direct jet thruster. Advocates of NOTAR believe the system offers quieter and safer operation over a traditional tail rotor. Development The use of directed air to provide anti-torque control had been tested as early as 1945 in the British Cierva W.9. During 1957, a Spanish prototype designed and built by Aerot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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