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Phugoid
In aviation, a phugoid or fugoid is an aircraft motion in which the vehicle pitches up and climbs, and then pitches down and descends, accompanied by speeding up and slowing down as it goes "downhill" and "uphill". This is one of the basic flight dynamics modes of an aircraft (others include short period, roll subsidence, dutch roll, and spiral divergence), and is a classic example of a positive feedback system. Detailed description The phugoid has a nearly constant angle of attack but varying pitch, caused by a repeated exchange of airspeed and altitude. It can be excited by an elevator singlet (a short, sharp deflection followed by a return to the centered position) resulting in a pitch increase with no change in trim from the cruise condition. As speed decays, the nose drops below the horizon. Speed increases, and the nose climbs above the horizon. Periods can vary from under 30 seconds for light aircraft to minutes for larger aircraft. Microlight aircraft typically s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Dynamic Modes
The dynamic stability of an aircraft refers to how the aircraft behaves after it has been disturbed following steady non-oscillating flight. Longitudinal modes Oscillating motions can be described by two parameters, the period of time required for one complete oscillation, and the time required to damp to half-amplitude, or the time to double the amplitude for a dynamically unstable motion. The longitudinal motion consists of two distinct oscillations, a long-period oscillation called a phugoid mode and a short-period oscillation referred to as the short-period mode. Phugoid (longer period) oscillations The longer period mode, called the "phugoid mode" is the one in which there is a large-amplitude variation of air-speed, pitch angle, and altitude, but almost no angle-of-attack variation. The phugoid oscillation is a slow interchange of kinetic energy (velocity) and potential energy (height) about some equilibrium energy level as the aircraft attempts to re-establish the equi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Period
The dynamic stability of an aircraft refers to how the aircraft behaves after it has been disturbed following steady non-oscillating flight. Longitudinal modes Oscillating motions can be described by two parameters, the period of time required for one complete oscillation, and the time required to damp to half-amplitude, or the time to double the amplitude for a dynamically unstable motion. The longitudinal motion consists of two distinct oscillations, a long-period oscillation called a phugoid mode and a short-period oscillation referred to as the short-period mode. Phugoid (longer period) oscillations The longer period mode, called the "phugoid mode" is the one in which there is a large-amplitude variation of air-speed, pitch angle, and altitude, but almost no angle-of-attack variation. The phugoid oscillation is a slow interchange of kinetic energy (velocity) and potential energy (height) about some equilibrium energy level as the aircraft attempts to re-establish the equil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Dynamic Modes
The dynamic stability of an aircraft refers to how the aircraft behaves after it has been disturbed following steady non-oscillating flight. Longitudinal modes Oscillating motions can be described by two parameters, the period of time required for one complete oscillation, and the time required to damp to half-amplitude, or the time to double the amplitude for a dynamically unstable motion. The longitudinal motion consists of two distinct oscillations, a long-period oscillation called a phugoid mode and a short-period oscillation referred to as the short-period mode. Phugoid (longer period) oscillations The longer period mode, called the "phugoid mode" is the one in which there is a large-amplitude variation of air-speed, pitch angle, and altitude, but almost no angle-of-attack variation. The phugoid oscillation is a slow interchange of kinetic energy (velocity) and potential energy (height) about some equilibrium energy level as the aircraft attempts to re-establish the equi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Divergence
The dynamic stability of an aircraft refers to how the aircraft behaves after it has been disturbed following steady non-oscillating flight. Longitudinal modes Oscillating motions can be described by two parameters, the period of time required for one complete oscillation, and the time required to damp to half-amplitude, or the time to double the amplitude for a dynamically unstable motion. The longitudinal motion consists of two distinct oscillations, a long-period oscillation called a phugoid mode and a short-period oscillation referred to as the short-period mode. Phugoid (longer period) oscillations The longer period mode, called the "phugoid mode" is the one in which there is a large-amplitude variation of air-speed, pitch angle, and altitude, but almost no angle-of-attack variation. The phugoid oscillation is a slow interchange of kinetic energy (velocity) and potential energy (height) about some equilibrium energy level as the aircraft attempts to re-establish the equ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilot-induced Oscillation
Pilot-induced oscillations (PIOs), as defined by MIL-HDBK-1797A, are ''sustained or uncontrollable oscillations resulting from efforts of the pilot to control the aircraft''. They occur when the pilot of an aircraft inadvertently commands an often increasing series of corrections in opposite directions, each an attempt to cover the aircraft's reaction to the previous input with an overcorrection in the opposite direction. An aircraft in such a condition can appear to be "porpoising" switching between upward and downward directions. As such it is a coupling of the frequency of the pilot's inputs and the aircraft's own frequency. During flight test, pilot-induced oscillation is one of the handling qualities factors that is analyzed, with the aircraft being graded by an established scale (chart at right). In order to avoid any assumption that oscillation is necessarily the fault of the pilot, new terms have been suggested to replace ''pilot-induced oscillation''. These include ''airc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan Airlines Flight 123
Japan Air Lines Flight 123 (JAL123) () was a scheduled domestic Japan Air Lines passenger flight from Haneda Airport in Tokyo to Itami International Airport in Osaka. On August 12, 1985, the Boeing 747SR operating this flight suffered a sudden decompression 12 minutes into the flight, and crashed in the area of Mount Takamagahara, Ueno, Gunma Prefecture, from Tokyo 32 minutes later. The crash site was on Osutaka Ridge, near Mount Osutaka. Japan's Aircraft Accident Investigation Commission (AAIC) concluded, agreeing with investigators from the U.S. National Transportation Safety Board, that the rapid decompression was caused by a faulty repair by Boeing technicians after a tailstrike incident during a landing at Osaka Airport in 1978 as JAL Flight 115. The rear bulkhead of the plane had been repaired with an improperly installed doubler plate, compromising the plane's airworthiness. Cabin pressurization continued to expand and contract the improperly repaired bulkhead until th ... [...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] |
Greek (language)
Greek ( el, label=Modern Greek, Ελληνικά, Elliniká, ; grc, Ἑλληνική, Hellēnikḗ) is an independent branch of the Indo-European family of languages, native to Greece, Cyprus, southern Italy ( Calabria and Salento), southern Albania, and other regions of the Balkans, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aviator
An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its Aircraft flight control system, directional flight controls. Some other aircrew, aircrew members, such as navigators or flight engineers, are also considered aviators, because they are involved in operating the aircraft's navigation and engine systems. Other aircrew members, such as drone operators, flight attendants, Aircraft maintenance technician, mechanics and Line technician (aviation), ground crew, are not classified as aviators. In recognition of the pilots' qualifications and responsibilities, most militaries and many airlines worldwide award aviator badges to their pilots. History The first recorded use of the term ''aviator'' (''aviateur'' in French) was in 1887, as a variation of ''aviation'', from the Latin ''avis'' (meaning ''bird''), coined in 1863 by in ''Aviation Ou Navigation Aérienne'' ("Aviation or Air Navigation"). The term ''aviatrix'' (''aviatrice'' in F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frederick W
Frederick may refer to: People * Frederick (given name), the name Nobility Anhalt-Harzgerode *Frederick, Prince of Anhalt-Harzgerode (1613–1670) Austria * Frederick I, Duke of Austria (Babenberg), Duke of Austria from 1195 to 1198 * Frederick II, Duke of Austria (1219–1246), last Duke of Austria from the Babenberg dynasty * Frederick the Fair (Frederick I of Austria (Habsburg), 1286–1330), Duke of Austria and King of the Romans Baden * Frederick I, Grand Duke of Baden (1826–1907), Grand Duke of Baden * Frederick II, Grand Duke of Baden (1857–1928), Grand Duke of Baden Bohemia * Frederick, Duke of Bohemia (died 1189), Duke of Olomouc and Bohemia Britain * Frederick, Prince of Wales (1707–1751), eldest son of King George II of Great Britain Brandenburg/Prussia * Frederick I, Elector of Brandenburg (1371–1440), also known as Frederick VI, Burgrave of Nuremberg * Frederick II, Elector of Brandenburg (1413–1470), Margrave of Brandenburg * Frederick William, Elector ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aft Pressure Bulkhead
The aft pressure bulkhead or rear pressure bulkhead is the rear component of the pressure seal in all aircraft that cruise in a tropopause zone in the earth's atmosphere. It helps maintain pressure when stratocruising and protects the aircraft from bursting due to the higher internal pressure. Design Aft pressure bulkheads can either be curved, which reduces the amount of metal needed at the cost of reducing the usable space in the airliner, or flat, which gives more internal space but also more weight. Patents have been filed that propose deliberately creating cavities within the rear bulkhead with the purpose of providing more usable cabin space. On several airliners, production of the rear pressure bulkhead has been outsourced to third party manufacturers. While typically being a time-consuming and somewhat uncommon process, an aircraft's aft pressure bulkhead can be wholly replaced. During the twenty-first century, various parties became increasingly interested in developing a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fokker F-27 Friendship
The Fokker F27 Friendship is a turboprop airliner developed and manufactured by the Dutch aircraft manufacturer Fokker. It is the most numerous post-war aircraft manufactured in the Netherlands; the F27 was also one of the most successful European airliners of its era. The F27 was developed during the early 1950s with the intent of producing a capable successor to the earlier piston engine-powered airliners that had become commonplace on the market, such as the Douglas DC-3. A key innovation of the F27 was the adoption of the Rolls-Royce Dart turboprop engine, which produced substantially less vibration and noise which provided improved conditions for passengers; another major comfort feature was cabin pressurisation. Innovative manufacturing techniques were also employed in the aircraft's construction. On 24 November 1955, the F27 made its maiden flight; on 19 November 1958, the type was introduced to revenue service. Shortly after its introduction, the F27 was recognised as be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
