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Hirth Hi25 Kria
The experimental Hirth Hi-25 Kria was only the second glider constructed from glass reinforced plastic (GRP). Built in Germany in 1958, it was a single seat, span aircraft. Only one was built; it later flew for several years with Akaflieg Stuttgart. Design and development The first glider with a GRP structure was the Akaflieg Stuttgart Phönix which flew in November 1957. Wolf Hirth had followed its construction with interest and had hoped to manufacture it. Instead, the Phönix was produced by Bölkow and Hirth built his own design, the Hi-25 Kria, using the construction methods developed for the Phönix. As well as their structural similarity, the Kria and the Phönix shared some aerodynamic features, particularly Eppler airfoils and fuselages which conformed to the upward flowing air ahead of the wings and downwash behind. The Kria, though, was a high wing rather than mid-wing monoplane, was smaller overall (the Phönix had a 16 m span) and had a butterfly tail. Kr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WikiProject Aircraft
A WikiProject, or Wikiproject, is a Wikimedia movement affinity group for contributors with shared goals. WikiProjects are prevalent within the largest wiki, Wikipedia, and exist to varying degrees within sister projects such as Wiktionary, Wikiquote, Wikidata, and Wikisource. They also exist in different languages, and translation of articles is a form of their collaboration. During the COVID-19 pandemic, CBS News noted the role of Wikipedia's WikiProject Medicine in maintaining the accuracy of articles related to the disease. Another WikiProject that has drawn attention is WikiProject Women Scientists, which was profiled by '' Smithsonian'' for its efforts to improve coverage of women scientists which the profile noted had "helped increase the number of female scientists on Wikipedia from around 1,600 to over 5,000". On Wikipedia Some Wikipedia WikiProjects are substantial enough to engage in cooperative activities with outside organizations relevant to the field at issue. For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Tern
The Arctic tern (''Sterna paradisaea'') is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south as Massachusetts). The species is strongly migratory, seeing two summers each year as it migrates along a convoluted route from its northern breeding grounds to the Antarctic coast for the southern summer and back again about six months later. Recent studies have shown average annual round-trip lengths of about for birds nesting in Iceland and Greenland and about for birds nesting in the Netherlands. These are by far the longest migrations known in the animal kingdom. The Arctic tern nests once every one to three years (depending on its mating cycle). Arctic terns are medium-sized birds. They have a length of and a wingspan of . They are mainly grey and white plumaged, with a red/orange beak and feet, white forehead, a black nape and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1950s German Sailplanes
Year 195 ( CXCV) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Scrapula and Clemens (or, less frequently, year 948 '' Ab urbe condita''). The denomination 195 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Emperor Septimius Severus has the Roman Senate deify the previous emperor Commodus, in an attempt to gain favor with the family of Marcus Aurelius. * King Vologases V and other eastern princes support the claims of Pescennius Niger. The Roman province of Mesopotamia rises in revolt with Parthian support. Severus marches to Mesopotamia to battle the Parthians. * The Roman province of Syria is divided and the role of Antioch is diminished. The Romans annexed the Syrian cities of Edessa and Nisibis. Severus re-establish his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopy (aircraft)
An aircraft canopy is the transparent enclosure over the cockpit of some types of aircraft. An aircraft canopy provides a controlled and sometimes pressurized environment for the aircraft's occupants, and allows for a greater field of view over a traditional flight deck. A canopy's shape is a compromise designed to minimize aerodynamic drag, while maximizing visibility for pilots and other crewmembers. History Very early aircraft had no canopies. The pilots were exposed to the wind and weather, although most flying was done in good weather. Through World War I most aircraft had no canopy, although they often had a small windshield to deflect the prop wash and wind from hitting the pilot in the face. In the 1920s and 1930s, the increasing speed and altitude of airplanes necessitated a fully enclosed cockpit and canopies became more common. Early canopies were made of numerous pieces of flat glass held in position by a frame and muntins. The muntins reduced visibility, which w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Brake (aircraft)
In aeronautics, air brakes or speed brakes are a type of flight control surface used on an aircraft to increase the drag on the aircraft. Air brakes differ from spoilers in that air brakes are designed to increase drag while making little change to lift, whereas spoilers reduce the lift-to-drag ratio and require a higher angle of attack to maintain lift, resulting in a higher stall speed. Introduction An air brake is a part of an aircraft. When extended into the airstream, it causes an increase in the drag on the aircraft. When not in use, it conforms to the local streamlined profile of the aircraft in order to help minimise the drag. History In the early decades of powered flight, air brakes were flaps mounted on the wings. They were manually controlled by a lever in the cockpit, and mechanical linkages to the air brake. An early type of air brake, developed in 1931, was fitted to the aircraft wing support struts. In 1936, Hans Jacobs, who headed Nazi Germany's '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around the aircraft's longitudinal axis), which normally results in a change in flight path due to the tilting of the lift vector. Movement around this axis is called 'rolling' or 'banking'. Considerable controversy exists over credit for the invention of the aileron. The Wright brothers and Glenn Curtiss fought a years-long legal battle over the Wright patent of 1906, which described a method of wing-warping to achieve lateral control. The brothers prevailed in several court decisions which found that Curtiss's use of ailerons violated the Wright patent. Ultimately, the First World War compelled the U.S. Government to legislate a legal resolution. A much earlier aileron concept was patented in 1868 by British scientist Matthew Piers Watt Bou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihedral (aircraft)
In aeronautics, dihedral is the angle between the left and right wings (or tail surfaces) of an aircraft. "Dihedral" is also used to describe the effect of sideslip on the rolling of the aircraft. Dihedral angle is the upward angle from horizontal of the wings or tailplane of a fixed-wing aircraft. "Anhedral angle" is the name given to negative dihedral angle, that is, when there is a ''downward'' angle from horizontal of the wings or tailplane of a fixed-wing aircraft. Dihedral angle has a strong influence on dihedral effect, which is named after it. Dihedral effect is the amount of roll moment produced in proportion to the amount of sideslip. Dihedral effect is a critical factor in the stability of an aircraft about the roll axis (the spiral mode). It is also pertinent to the nature of an aircraft's Dutch roll oscillation and to maneuverability about the roll axis. Longitudinal dihedral is a comparatively obscure term related to the pitch axis of an airplane. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trailing Edge
The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. Essential flight control surfaces are attached here to control the direction of the departing air flow, and exert a controlling force on the aircraft. Such control surfaces include ailerons on the wings for roll control, elevators on the tailplane controlling pitch, and the rudder on the fin controlling yaw. Elevators and ailerons may be combined as elevons on tailless aircraft. The shape of the trailing edge is of prime importance in the aerodynamic function of any aerodynamic surface. George Batchelor has written about: :“ ... the remarkable controlling influence exerted by the sharp trailing edge of an aerofoil on the circulation.”Batchelor, G. K. (1967), ''An Introduction to Fluid Dynamics'', p.438, Cambridge University Press. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leading Edge
The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, 1997. Characteristics Sweep Seen in plan the leading edge may be straight, curved, kinked or a combination of these. A straight leading edge may be swept or unswept, while curves or kinks always mean that part of the leading edge is swept. On a swept wing the sweep angle may differ from that of the wing, as wing sweep is conventionally measured at the airfoil 25% chord line. However on a delta wing the leading edge sweep defines the wing sweep. Radius and stagnation point A rounded leading edge helps to maintain a smooth airflow at varying angles of incidence to the airflow. Most subsonic airfoils therefore have a rounded leading edge. The degree of rounding is characterised by the profile radius at that point. The airflow divides to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wing Tip
A wing tip (or wingtip) is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft. Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of shapes, including: * Squared-off * Aluminium tube bow * Rounded * Hoerner style * Winglets * Drooped tips * Raked wingtips * Tip tanks * Sails * Fences * End plates Winglets have become popular additions to high speed aircraft to increase fuel efficiency by reducing drag from wingtip vortices. In lower speed aircraft, the effect of the wingtip shape is less apparent, with only a marginal performance difference between round, square, and Hoerner style tips The slowest speed aircraft, STOL aircraft, may use wingtips to shape airflow for controllability at low airspeeds. Wing tips are also an expression of aircraft design style, so their shape may be influenced by marketing considerations as well as by aerodynamic requirements. Wing tips are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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