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V-speed
In aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot air ..., V-speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft. These speeds are derived from data obtained by aircraft designers and manufacturers during flight testing for aircraft Type certificate, type-certification. Using them is considered a best practice to maximize aviation safety, aircraft performance, or both. The actual speeds represented by these designators are specific to a particular model of aircraft. They are expressed by the aircraft's indicated airspeed (and not by, for example, the ground speed), so that pilots may use them directly, without having to apply correction factors, as aircraft instruments also show indicated airspeed. In general aviation aircr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of Climb
In aerodynamics, climb gradient is the ratio between distance travelled over the ground and altitude gained, and is expressed as a percentage. The angle of climb can be defined as the angle between a horizontal plane representing the Earth's surface and the actual flight path followed by the aircraft during its ascent. The speed of an aircraft type at which the angle of climb is largest is called VX. It is always slower than VY, the speed for the best rate of climb. As the latter gives the quickest way for gaining altitude levels, regardless of the distance covered during such a maneuver, it is more relevant to cruising. The maximum angle of climb on the other hand is where the aircraft gains the most altitude in a given distance, regardless of the time needed for the maneuver. This is important for clearing an obstacle, and therefore is the speed a pilot uses when executing a "short field" takeoff. VX increases with altitude and VY decreases with altitude until they converge at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total area. Its southern and western border with the United States, stretching , is the world's longest binational land border. Canada's capital is Ottawa, and its three largest metropolitan areas are Toronto, Montreal, and Vancouver. Indigenous peoples have continuously inhabited what is now Canada for thousands of years. Beginning in the 16th century, British and French expeditions explored and later settled along the Atlantic coast. As a consequence of various armed conflicts, France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces. This began an accretion of provinces an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation (aeronautics)
In aviation, rotation refers to the action of applying back pressure to a control device, such as a yoke, side-stick or centre stick, to lift the nose wheel off the ground during takeoff. The aircraft rotates around its lateral axis. Rotation is begun at the speed known as VR. Rotation at the correct speed and to the correct angle is important for safety reasons and to decrease takeoff distance. After rotation, the aircraft continues to accelerate until it reaches its liftoff speed VLO, at which point it leaves the runway. Over-rotation can cause a tailstrike, which can damage the underside of the tail unless prevented by a protection device such as a tailskid or tail bumper. A certification test is required to show that a new aircraft design will still take off safely with the tail dragging on the runway. Using a higher VR will increase tail clearance and reduce the probability of tailstrike. Description Rotation applies to tricycle gear aircraft rather than those with convent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersonic
Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times the speed of sound (Mach 5) are often referred to as hypersonic. Flights during which only some parts of the air surrounding an object, such as the ends of rotor blades, reach supersonic speeds are called transonic. This occurs typically somewhere between Mach 0.8 and Mach 1.2. Sounds are traveling vibrations in the form of pressure waves in an elastic medium. Objects move at supersonic speed when the objects move faster than the speed at which sound propagates through the medium. In gases, sound travels longitudinally at different speeds, mostly depending on the molecular mass and temperature of the gas, and pressure has little effect. Since air temperature and composition varies significantly with altitude, the speed of s ... [...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 rotati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Control Speed
The minimum control speed (VMC) of a multi-engine aircraft (specifically an airplane) is a V-speed that specifies the calibrated airspeed below which directional or lateral control of the aircraft can no longer be maintained, after the failure of one or more engines. The VMC only applies if at least one engine is still operative, and will depend on the stage of flight. Indeed, multiple VMCs have to be calculated for landing, air travel, and ground travel, and there are more still for aircraft with four or more engines. These are all included in the aircraft flight manual of all multi-engine aircraft. When design engineers are sizing an airplane's vertical tail and flight control surfaces, they have to take into account the effect this will have on the airplane's minimum control speeds. Minimum control speeds are typically established by flight tests as part of an aircraft certification process. They provide a guide to the pilot in the safe operation of the aircraft. Physical des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Control Speed
The minimum control speed (VMC) of a multi-engine aircraft (specifically an airplane) is a V-speed that specifies the calibrated airspeed below which directional or lateral control of the aircraft can no longer be maintained, after the failure of one or more engines. The VMC only applies if at least one engine is still operative, and will depend on the stage of flight. Indeed, multiple VMCs have to be calculated for landing, air travel, and ground travel, and there are more still for aircraft with four or more engines. These are all included in the aircraft flight manual of all multi-engine aircraft. When design engineers are sizing an airplane's vertical tail and flight control surfaces, they have to take into account the effect this will have on the airplane's minimum control speeds. Minimum control speeds are typically established by flight tests as part of an aircraft certification process. They provide a guide to the pilot in the safe operation of the aircraft. Physical des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Engine
The critical engine of a multi-engine fixed-wing aircraft is the engine that, in the event of failure, would most adversely affect the performance or handling abilities of an aircraft. On propeller aircraft, there is a difference in the remaining yawing moments after failure of the left or the right (outboard) engine when all propellers rotate in the same direction due to the P-factor. On turbojet and turbofan twin-engine aircraft, there usually is no difference between the yawing moments after failure of a left or right engine in no-wind condition. Description When one of the engines on a typical multi-engine aircraft becomes inoperative, a thrust imbalance exists between the operative and inoperative sides of the aircraft. This thrust imbalance causes several negative effects in addition to the loss of one engine's thrust. The tail-design engineer is responsible for determining the size of vertical stabilizer that will comply with the regulatory requirements for the control an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cruise (aeronautics)
Cruise is the phase of aircraft flight that starts when the aircraft levels off after a climb, until it begins to descend for landing. Cruising usually consumes the majority of a flight, and it may include changes in heading (direction of flight), airspeed and altitude. Commercial or passenger aircraft are usually designed for optimum performance around their cruise speed ( VC) and cruise altitude. Factors affecting optimum cruise speed and altitude include payload, center of gravity, air temperature, and humidity. Cruise altitude is usually where the higher ground speed is balanced against the decrease in engine thrust and efficiency at higher altitudes. A typical cruising airspeed for a long-distance commercial passenger aircraft is approximately . The typical cruising altitude for commercial airliners is . The speed which covers the greatest distance for a given amount of fuel is known as the maximum range speed. This is the speed at which drag is minimised. For jet aircraft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Gust
A gust or wind gust is a brief increase in the speed of the wind, usually less than 20 seconds. It is of a more transient character than a squall, which lasts minutes, and is followed by a lull or slackening in the wind speed. Generally, winds are least gusty over large water surfaces and most gusty over rough land and near high buildings. Definition The wind is measured using an anemometer or estimated with a windsock. The average value of wind speed is generally measured over a period of 2 minutes before the meteorological observation according to the World Meteorological Organization. Any significant variation at this mean wind during the ten minutes preceding the observation are noted as gusts in messages such as METAR. It is generally reported in METAR when the peak wind speed reaches at least 16 knots and the variation in wind speed between the peaks and average wind is at least 9 to 10 knots. In marine meteorology, the top speed of a burst is expressed in meters per second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maneuvering Speed
In aviation, the maneuvering speed of an aircraft is an airspeed limitation selected by the designer of the aircraft. At speeds close to, and faster than, the maneuvering speed, full deflection of any flight control surface should not be attempted because of the risk of damage to the aircraft structure.Federal Aviation AdministrationAdvisory Circular 23-19A, ''Airframe Guide for Certification of Part 23 Airplanes'', Section 48 (p.27)Retrieved 2012-01-06 The maneuvering speed of an aircraft is shown on a cockpit placard and in the aircraft's flight manual but is not commonly shown on the aircraft's airspeed indicator. In the context of air combat maneuvering (ACM), the maneuvering speed is also known as corner speed or cornering speed. Implications It has been widely misunderstood that flight below maneuvering speed will provide total protection from structural failure. In response to the destruction of American Airlines Flight 587, a CFR Final Rule was issued clarifying th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Aviation Authority (United Kingdom)
The Civil Aviation Authority (CAA) is the statutory corporation which oversees and regulates all aspects of civil aviation in the United Kingdom. Its areas of responsibility include: * Supervising the issuing of pilots' licences, testing of equipment, calibrating of navaids, and many other inspections (Civil Aviation Flying Unit). * Managing the regulation of security standards, including vetting of all personnel in the aviation industry (Directorate of Aviation Security). * Overseeing the national protection scheme for customers abroad in the event of a travel company failure (Air Travel Organisers' Licensing – ATOL). The CAA is a public corporation of the Department for Transport, liaising with the government via the Standards Group of the Cabinet Office. Responsibilities The CAA directly or indirectly regulates all aspects of aviation in the UK. In some aspects of aviation it is the primary regulator. The UK government requires that the CAA's costs are met entirely fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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