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Flying Qualities
Flying qualities is one of the three principal regimes in the science of flight test, which also includes performance and systems. Flying qualities involves the study and evaluation of the stability and control characteristics of an aircraft. They have a critical bearing on the safety of flight and on the ease of controlling an airplane in steady flight and in maneuvers. Relation to stability To understand the discipline of flying qualities, the concept of stability should be understood. Stability can be defined only when the vehicle is in trim; that is, there are no unbalanced forces or moments acting on the vehicle to cause it to deviate from steady flight. If this condition exists, and if the vehicle is disturbed, stability refers to the tendency of the vehicle to return to the trimmed condition. If the vehicle initially tends to return to a trimmed condition, it is said to be statically stable. If it continues to approach the trimmed condition without overshooting, the motion is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Test
Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. Data is sampled during the flight of an aircraft, or Atmosphere of Earth, atmospheric testing of launch vehicles and Reusable launch vehicle, reusable spacecraft. This data is validated for accuracy and analyzed before being passed to specialist engineering groups for further analysis to Verification and validation, validate the design of the vehicle. The flight test phase accomplishes two major tasks: 1) finding and fixing any Aeronautics, design problems and then 2) verification and validation, verifying and documenting the vehicle capabilities for government certification or customer acceptance. The flight test phase can range from the test of a single new system for an existing vehicle to the complete development and certification of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Engli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
NACA
The National Advisory Committee for Aeronautics (NACA) was a United States federal agency founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its assets and personnel were transferred to the newly created National Aeronautics and Space Administration (NASA). NACA is an initialism, i.e., pronounced as individual letters, rather than as a whole word (as was NASA during the early years after being established). Among other advancements, NACA research and development produced the NACA duct, a type of air intake used in modern automotive applications, the NACA cowling, and several series of NACA airfoils, which are still used in aircraft manufacturing. During World War II, NACA was described as "The Force Behind Our Air Supremacy" due to its key role in producing working superchargers for high altitude bombers, and for producing the laminar wing profiles for the North American P-51 Mustang. N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hartley A
Hartley may refer to: Places Australia * Hartley, New South Wales * Hartley, South Australia **Electoral district of Hartley, a state electoral district Canada *Hartley Bay, British Columbia United Kingdom * Hartley, Cumbria * Hartley, Plymouth, Devon *Hartley Wespall, Hampshire * Hartley, Sevenoaks, Kent * Hartley, Tunbridge Wells, Kent * Hartley, Northumberland (Old Hartley), part of Seaton Sluice *New Hartley, Northumberland United States * Hartley, California *Hartley, Iowa * Hartley, Michigan * Hartley, South Dakota * Hartley, Texas * Hartley County, Texas *Brohard, West Virginia, also Hartley Zimbabwe *Chegutu, formerly Hartley People * Hartley (surname) * Hartley Burr Alexander, (1873–1939), American philosopher * Hartley Alleyne (born 1957), Barbadian cricketer * Hartley Booth (born 1946), British politician * Hartley Coleridge (1796–1849), English writer * Hartley Craig (1917–2007), Australian cricketer * Hartley Douglas Dent (1929–1993), Canadian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert R
Robert Lee Rayford (February 3, 1953 – May 15 1969), sometimes identified as Robert R. due to his age, was an American teenager from Missouri who has been suggested to represent the earliest confirmed case of HIV/AIDS in North America based on evidence which was published in 1988 in which the authors claimed that medical evidence indicated that he was "infected with a virus closely related or identical to human immunodeficiency virus type 1." Rayford died of pneumonia, but his other symptoms baffled the doctors who treated him. A study published in 1988 reported the detection of antibodies against HIV. Results of testing for HIV genetic material were reported once at a scientific conference in Australia in 1999; however, the data has never been published in a peer-reviewed medical or scientific journal. Background Robert Rayford was born on February 3, 1953, in St. Louis, Missouri to Constance Rayford (September 12, 1931 – April 3, 2011) and Joseph Benny Bell (March 24, 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melvin N
Melvin is a masculine given name and surname, likely a variant of Melville and a descendant of the French surname de Maleuin and the later Melwin. It may alternatively be spelled as Melvyn or, in Welsh, Melfyn and the name Melivinia or Melva may be used a feminine form. Of Norman French origin, originally Malleville, which translates to "bad town," it likely made its way into usage in Scotland as a result of the Norman conquest of England. It came into use as a given name as early as the 19th century, in English-speaking populations. As a name Given name Academics *Melvin Calvin (1911–1997), American chemist who discovered the Calvin cycle *Melvin Day (1923–2016), New Zealand artist and art historian *Melvin Hochster (born 1943), American mathematician *Melvin Konner (born 1946), Professor of Anthropology *Melvin Schwartz (1932–2006), American physicist who won the Nobel Prize in Physics in 1988 * Melvin Alvah Traylor, Jr. (1915–2008), American ornithologist Busin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Test
Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. Data is sampled during the flight of an aircraft, or Atmosphere of Earth, atmospheric testing of launch vehicles and Reusable launch vehicle, reusable spacecraft. This data is validated for accuracy and analyzed before being passed to specialist engineering groups for further analysis to Verification and validation, validate the design of the vehicle. The flight test phase accomplishes two major tasks: 1) finding and fixing any Aeronautics, design problems and then 2) verification and validation, verifying and documenting the vehicle capabilities for government certification or customer acceptance. The flight test phase can range from the test of a single new system for an existing vehicle to the complete development and certification of a ... [...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] |
Longitudinal Static Stability
In flight dynamics, longitudinal stability is the stability of an aircraft in the longitudinal, or pitching, plane. This characteristic is important in determining whether an aircraft pilot will be able to control the aircraft in the pitching plane without requiring excessive attention or excessive strength. The longitudinal stability of an aircraft, also called pitch stability, refers to the aircraft's stability in its plane of symmetry about the lateral axis (the axis along the wingspan). It is an important aspect of the handling qualities of the aircraft, and one of the main factors determining the ease with which the pilot is able to maintain level flight. Longitudinal static stability refers to the aircraft's initial tendency on pitching. Dynamic stability refers to whether oscillations tend to increase, decrease or stay constant. Static stability If an aircraft is longitudinally statically stable, a small increase in angle of attack will create a nose-down pitching mom ... [...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. 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. Flight envelope is one of a number of related terms that are all 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 flying. It is closely related to more modern terms known as extra power and a doghouse plot which are different ways of describing a flight envelope. In addition, the term has been widened in scope outside the field of engineering, to refer to the strict limits in which an event will take place or mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
