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Servo Transparency
In aviation, and in particular in helicopters, servo transparency (also called servo reversibility or jack stall), is a phenomenon affecting the servomechanisms (or ''servos'') that assist a Helicopter flight controls, helicopter's flight controls, which, in certain flight conditions, can result in a significant stiffening of the controls handled by the pilot. The effect, if not promptly recognised by the pilot, can be hazardous as it can lead to partial or total Loss of control (aeronautics), loss of control, which, if encountered at low altitude, could result in impact with terrain. Background Helicopter flight controls are connected to the Helicopter rotor, main and tail rotors, and include a cyclic stick, broadly to control forward-aft and left-right movements, a collective lever, broadly to control vertical movements, and anti-torque pedals, to control left and right Yaw (aviation), yaw. The forces applied to such controls by the pilot are opposed by aerodynamic forces act ... [...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] |
Flight Envelope
In aerodynamics, the flight envelope, service envelope, or performance envelope of an aircraft or spacecraft refers to the capabilities of a design in terms of airspeed and load factor or atmospheric density, often simplified to altitude. The term is somewhat loosely applied, and can also refer to other measurements such as maneuverability. For example, when a plane is pushed, for instance by diving it at high speeds, it is said to be flown "outside the envelope", something considered rather dangerous. During vehicle test programs, flight envelope simply means that part of the aircraft or spacecraft's design capabilities that have already been successfully tested, and have therefore moved from theoretical or designed capability into a demonstrated/certified capability. Flight envelope is one of a number of related terms that are used in a similar fashion. It is perhaps the most common term because it is the oldest, first being used in the early days of test flight. It is clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EASA
The European Union Aviation Safety Agency (EASA) is an agency of the European Commission with responsibility for civil aviation safety in the European Union. It carries out certification, regulation and standardisation and also performs investigation and monitoring. It collects and analyses safety data, drafts and advises on safety legislation and co-ordinates with similar organisations in other parts of the world. The idea of a European-level aviation safety authority goes back to 1996, but the agency was legally established only in 2002; it began its work in 2003. History Based in Cologne, Germany, the agency was created on 15 July 2002 as the "European Aviation Safety Agency", and reached full functionality in 2008, taking over functions of the Joint Aviation Authorities. It was renamed the "European Union Aviation Safety Agency" in 2018. European Free Trade Association countries participate in the agency. The United Kingdom was a member until the end of the Brexit trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurocopter AS350
Airbus Helicopters SAS (formerly Eurocopter S.A., trading as Eurocopter Group) is the helicopter manufacturing division of Airbus. It is the largest in the industry in terms of revenues and turbine helicopter deliveries, holding 48% of the worldwide market share as of 2020. Its head office is located at Marseille Provence Airport in Marignane, France, near Marseille. The main facilities of Airbus Helicopters are at its headquarters in Marignane, France, and in Donauwörth, Germany, with additional production plants in Spain, Brazil, Canada, Australia, Romania, the United Kingdom and the United States. The company, originally named Eurocopter, was rebranded Airbus Helicopters on 2 January 2014. History Airbus Helicopters was formed in 1992 as ''Eurocopter S.A.'', through the merger of the helicopter divisions of Aérospatiale and DASA. The company's heritage traces back to Blériot and Lioré et Olivier in France and to Messerschmitt and Focke-Wulf in Germany. Aérospatiale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density Altitude
The density altitude is the altitude relative to standard atmospheric conditions at which the air density would be equal to the indicated air density at the place of observation. In other words, the density altitude is the air density given as a height above mean sea level. The density altitude can also be considered to be the pressure altitude adjusted for a non-standard temperature. Both an increase in the temperature and a decrease in the atmospheric pressure, and, to a much lesser degree, an increase in the humidity, will cause an increase in the density altitude. In hot and humid conditions, the density altitude at a particular location may be significantly higher than the true altitude. In aviation, the density altitude is used to assess an aircraft's aerodynamic performance under certain weather conditions. The lift generated by the aircraft's airfoils, and the relation between its indicated airspeed (IAS) and its true airspeed (TAS), are also subject to air-density ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-force
The g-force or gravitational force equivalent is a Specific force, mass-specific force (force per unit mass), expressed in Unit of measurement, units of standard gravity (symbol ''g'' or ''g''0, not to be confused with "g", the symbol for grams). It is used for sustained accelerations that cause a perception of weight. For example, an object at rest on Earth's surface is subject to 1 ''g'', equaling the conventional value of gravitational acceleration on Earth, about . More transient acceleration, accompanied with significant jerk (physics), jerk, is called Shock (mechanics), ''shock''. When the g-force is produced by the surface of one object being pushed by the surface of another object, the reaction force to this push produces an equal and opposite force for every unit of each object's mass. The types of forces involved are transmitted through objects by interior Stress (mechanics), mechanical stresses. Gravitational acceleration is one cause of an object's accelera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transportation Safety Board Of Canada
The Transportation Safety Board of Canada (TSB, ), officially the Canadian Transportation Accident Investigation and Safety Board () is the agency of the Government of Canada responsible for advancing transportation safety in Canada. It is accountable to Parliament directly through the President of the King’s Privy Council and the Minister of Intergovernmental and Northern Affairs and Internal Trade. The independent agency investigates accidents and makes safety recommendations in four modes of transportation: aviation, rail, marine and pipelines. Agency history Prior to 1990, Transport Canada's Aircraft Accident Investigation Branch (1960–1984) and its successor the Canadian Aviation Safety Board or CASB (1984–1990) were responsible for investigation of air incidents. Before 1990, investigations and actions were taken by Transport Canada and even after 1984 the findings from CASB were not binding for Transport Canada to respond to. The TSB was created under the ''Cana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bank Angle
A banked turn (or banking turn) is a turn or change of direction in which the vehicle banks or inclines, usually towards the inside of the turn. For a road or railroad this is usually due to the roadbed having a transverse down-slope towards the inside of the curve. The bank angle is the angle at which the vehicle is inclined about its longitudinal axis with respect to the horizontal. Turn on flat surfaces If the bank angle is zero, the surface is flat and the normal force is vertically upward. The only force keeping the vehicle turning on its path is friction, or traction. This must be large enough to provide the centripetal force, a relationship that can be expressed as an inequality, assuming the car is driving in a circle of radius r: :\mu mg > . The expression on the right hand side is the centripetal acceleration multiplied by mass, the force required to turn the vehicle. The left hand side is the maximum frictional force, which equals the coefficient of friction \mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airspeed
In aviation, airspeed is the speed of an aircraft relative to the air it is flying through (which itself is usually moving relative to the ground due to wind). In contrast, the ground speed is the speed of an aircraft with respect to the surface of the Earth (whether over land or presumed-stationary water). It is difficult to measure the exact airspeed of the aircraft (true airspeed), but other measures of airspeed, such as indicated airspeed and Mach number give useful information about the capabilities and limitations of airplane performance. The common measures of 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. * True airspeed (TAS) is the actual speed the airplane is moving through the air. When combined with aircraft direction, wind speed and direction, it can be used to calculate ground speed and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retreating Blade Stall
Retreating blade stall is a hazardous flight condition in helicopters and other rotary wing aircraft, where the retreating rotor blade has a lower relative blade speed, combined with an increased angle of attack, causing a stall and loss of lift. Retreating blade stall is the primary limiting factor of a helicopter's never exceed speed, VNE. Retreating blade stall occurs at high forward speeds, and should not be confused with rotor stall, which is caused by low rotor RPM and can occur at any forward speed. Advancing vs. retreating blades A rotor blade that is moving in the same direction as the aircraft is called the ''advancing blade'' and the blade moving in the opposite direction is called the ''retreating blade.'' Balancing lift across the rotor disc is important to a helicopter's stability. The amount of lift generated by an airfoil is proportional to the square of its airspeed (velocity). In a zero airspeed hover the rotor blades, regardless of their position in rota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroscopic Effect
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, due to the conservation of angular momentum. Gyroscopes based on other operating principles also exist, such as the microchip-packaged MEMS gyroscopes found in electronic devices (sometimes called gyrometers), solid-state ring lasers, fibre optic gyroscopes, and the extremely sensitive quantum gyroscope. Applications of gyroscopes include inertial navigation systems, such as in the Hubble Space Telescope, or inside the steel hull of a submerged submarine. Due to their precision, gyroscopes are also used in gyrotheodolites to maintain direction in tunnel mining. Gyroscopes can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
