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Terminal Manoeuvring Area
In aviation, a terminal control area (TMA, or TCA in the U.S. and Canada), is a designated area of controlled airspace surrounding a major airport where there is a high volume of traffic. TMA airspace is normally designed in a circular configuration centered on the airport, and differs from a control area in that it includes several levels of increasingly larger areas, creating an "upside-down wedding cake" shape. In Canada, the inner circle of the TCA is generally a 12 NM radius from the airport geographic center based at 1200 feet AGL, with an intermediate circle at 35 NM based at 2200 feet AGL, and an outer limit at 45 NM radius based at 9500 feet AGL. In Canada, the TCA is normally designated as class B, C or D. In the U.S., the airspace of a TCA is typically designated as class B. In the U.K., the airspace of a TMA is usually designated as class A, D or E. In Australia, "terminal airspace" is not used both in common vernacular or publication and legislation. However, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 balloons and airships. Aviation began in the 18th century with the development of the hot air balloon, an apparatus capable of atmospheric displacement through buoyancy. Some of the most significant advancements in aviation technology came with the controlled gliding flying of Otto Lilienthal in 1896; then a large step in significance came with the construction of the first powered airplane by the Wright brothers in the early 1900s. Since that time, aviation has been technologically revolutionized by the introduction of the jet which permitted a major form of transport throughout the world. Etymology The word ''aviation'' was coined by the French writer and former naval officer Gabriel La Landelle in 1863. He derived the term from the v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Controlled Airspace
Controlled airspace is airspace of defined dimensions within which air traffic control (ATC) services are provided. The level of control varies with different classes of airspace. Controlled airspace usually imposes higher weather minimums than are applicable in uncontrolled airspace. It is the opposite of uncontrolled airspace. Controlled airspace is established mainly for three different reasons: * high-volume air traffic areas, e.g. near airports * Instrument flight rules traffic under ATC guidance * security, e.g. within an Air Defense Identification Zone Controlled airspace usually exists in the immediate vicinity of busier airports, where aircraft used in commercial air transport flights are climbing out from or making an approach to the airport, or at higher levels where air transport flights would tend to cruise. Some countries also provide controlled airspace almost generally, however in most countries it is common to provide uncontrolled airspace in areas where si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Area (aviation)
In aviation, a control area (CTA) is the volume of controlled airspace that exists in the vicinity of an airport. It has a specified lower level and a specified upper level. It usually is situated on top of a control zone and provides protection to aircraft climbing out from the airport by joining the low-level control zone to the nearest airways. In the UK they are generally class A, D or E. Control areas are particularly useful where there are busy airports located close together. In this case a single CTA will sit over all of the individual airports' CTRs. In larger-scale cases, this is known as a terminal manoeuvring area (TMA). See also *Airway (aviation) *Flight information region In aviation, a flight information region (FIR) is a specified region of airspace in which a flight information service and an alerting service (ALRS) are provided. The International Civil Aviation Organization (ICAO) delegates which country is re ... Air traffic control {{Commercial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Mile
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today the international nautical mile is defined as exactly . The derived unit of speed is the knot, one nautical mile per hour. Unit symbol There is no single internationally agreed symbol, with several symbols in use. * M is used as the abbreviation for the nautical mile by the International Hydrographic Organization. * NM is used by the International Civil Aviation Organization. * nmi is used by the Institute of Electrical and Electronics Engineers and the United States Government Publishing Office. * nm is a non-standard abbreviation used in many maritime applications and texts, including U.S. Government Coast Pilots and Sailing Directions. It conflicts with the SI symbol for nanometre. History The word mile is from the Latin word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Above Ground Level
In aviation, atmospheric sciences and broadcasting, a height above ground level (AGL or HAGL) is a height measured with respect to the underlying ground surface. This is as opposed to height above mean sea level (AMSL or HAMSL), height above ellipsoid (HAE, as reported by a GPS receiver), or height above average terrain (AAT or HAAT, in broadcast engineering). In other words, these expressions (AGL, AMSL, HAE, AAT) indicate where the "zero level" or "reference altitude" - the vertical datum - is located. Aviation A pilot flying an aircraft under instrument flight rules (typically under poor visibility conditions) must rely on the aircraft's altimeter to decide when to deploy the undercarriage and prepare for landing. Therefore, the pilot needs reliable information on the height of the plane with respect to the landing area (usually an airport). The altimeter, which is usually a barometer calibrated in units of distance instead of atmospheric pressure, can therefore be set in su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vernacular
A vernacular or vernacular language is in contrast with a "standard language". It refers to the language or dialect that is spoken by people that are inhabiting a particular country or region. The vernacular is typically the native language, normally spoken informally rather than written, and seen as of lower status than more codified forms. It may vary from more prestigious speech varieties in different ways, in that the vernacular can be a distinct stylistic register, a regional dialect, a sociolect, or an independent language. Vernacular is a term for a type of speech variety, generally used to refer to a local language or dialect, as distinct from what is seen as a standard language. The vernacular is contrasted with higher-prestige forms of language, such as national, literary, liturgical or scientific idiom, or a ''lingua franca'', used to facilitate communication across a large area. According to another definition, a vernacular is a language that has not develope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airway (aviation)
In the United States, airways or air routes are defined by the Federal Aviation Administration (FAA) in two ways: "VOR Federal airways and Low/Medium Frequency (L/MF) (Colored) Federal airways" These are designated routes which aeroplanes fly to aid in navigation and help with separation to avoid accidents. Airways are defined with segments within a specific altitude block, corridor width, and between fixed geographic coordinates for satellites navigation system, or between ground-based radio transmitter navigational aids (navaids; such as VORs or NDBs) or the intersection of specific radials of two navaids. United States To guide airmail pilots on their delivery routes, the United States Postal Service constructed the first airways in the United States, the Contract Air Mail routes. These airways were between major cities and identified at night by a series of flashing lights and beacons which pilots flew over in sequence to get from one city to the next. Intermediate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Zone
A control zone (CTR) in aviation is a volume of controlled airspace, usually situated below a control area, normally around an airport, which extends from the ''surface'' to a ''specified upper limit'', established to protect air traffic operating to and from that airport. Because CTRs are, by definition, controlled airspace, aircraft can only fly in it after receiving a specific clearance from air traffic control. This means that air traffic control at the airport know exactly which aircraft are in that airspace, and can take steps to ensure aircraft are aware of each other, either using separation or by passing traffic information. In the USA the term control zone is no longer used and has been replaced by airspace class D. Typically it extends 5 miles in diameter with a height of 2500 ft AGL (above ground level) around small commercial airports. Aircraft are required to establish radio contact with the control tower before entering and to maintain in contact while in class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Information Region
In aviation, a flight information region (FIR) is a specified region of airspace in which a flight information service and an alerting service (ALRS) are provided. The International Civil Aviation Organization (ICAO) delegates which country is responsible for the operational control of a given FIR. FIRs are the largest regular division of airspace in use in the world today, and have existed at least since 1947. Smaller countries' airspace is encompassed by a single FIR; larger countries' airspace is subdivided into a number of regional FIRs. Some FIRs encompass the territorial airspace of several countries. Oceanic airspace is divided into oceanic information regions and delegated to a controlling authority bordering that region. The division among authorities is done by international agreement through the International Civil Aviation Organization (ICAO). There is no standard size for FIRs–some are merely vertical extensions of their respective countries, however small they m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
