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Praga E-40
The Praga E-40 was a single engine, two seat, biplane basic trainer, built in Czechoslovakia in the mid-1930s. Design and development The E-40, one of several Praga trainer designs, was a single-bay biplane with open, tandem cockpits. The swept wings had twin wooden spars and a mixture of plywood and fabric covering. Ailerons were fitted to the lower wing and the upper wing had a cut-out on its trailing edge to enhance visibility from the forward cockpit. The N-form interplane struts were steel and the bay braced with streamlined wires. A pair of vertical N-form struts joined the wing centre section to the upper fuselage. The fixed tail surfaces were wood framed and plywood covered; the tailplane was strut braced from below. Elevators and rudder were fabric covered over steel frames. The rudder had a trim tab. The fuselage of the E-40 was a steel structure, rigidly braced at the front and wire braced aft. The nose and the upper decking were covered with detachable steel ... [...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 Wikimedia project, 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 Magazine, 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 organization ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streamlined
Streamlines, streaklines and pathlines are field lines in a fluid flow. They differ only when the flow changes with time, that is, when the flow is not steady. Considering a velocity vector field in three-dimensional space in the framework of continuum mechanics, we have that: * Streamlines are a family of curves whose tangent vectors constitute the velocity vector field of the flow. These show the direction in which a massless fluid element will travel at any point in time. * Streaklines are the loci of points of all the fluid particles that have passed continuously through a particular spatial point in the past. Dye steadily injected into the fluid at a fixed point extends along a streakline. * Pathlines are the trajectories that individual fluid particles follow. These can be thought of as "recording" the path of a fluid element in the flow over a certain period. The direction the path takes will be determined by the streamlines of the fluid at each moment in time. * Tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1930s Czechoslovakian Aircraft
Year 193 ( CXCIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Sosius and Ericius (or, less frequently, year 946 ''Ab urbe condita''). The denomination 193 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 * January 1 – Year of the Five Emperors: The Roman Senate chooses Publius Helvius Pertinax, against his will, to succeed the late Commodus as Emperor. Pertinax is forced to reorganize the handling of finances, which were wrecked under Commodus, to reestablish discipline in the Roman army, and to suspend the food programs established by Trajan, provoking the ire of the Praetorian Guard. * March 28 – Pertinax is assassinated by members of the Praetorian Guard, who storm the imperial palace. The Empire is auctioned of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praga Aircraft
Praga is a district of Warsaw, Poland. It is on the east bank of the river Vistula. First mentioned in 1432, until 1791 it formed a separate town with its own city charter. History The historical Praga was a small settlement located at the eastern bank of the Vistula river, directly opposite the towns of Old Warsaw and Mariensztat, both being parts of Warsaw now. First mentioned in 1432, it derived its name from the Polish verb ''prażyć'', meaning ''to burn'' or ''to roast'', as it occupied a forested area that was burnt out to make place for the village. Separated from Warsaw by a wide river, it developed independently of the nearby city, and on 10 February 1648 king Władysław IV of Poland granted Praga with a city charter. However, as it was mostly a suburb and most buildings were wooden, the town was repeatedly destroyed by fires, floods and foreign armies. Currently the only surviving historical monument from that epoch is the Church of Our Lady of Loreto. Altho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caster
A caster (or castor) is an undriven wheel that is designed to be attached to the bottom of a larger object (the "vehicle") to enable that object to be moved. Casters are used in numerous applications, including shopping carts, office chairs, toy wagons, hospital beds, and material handling equipment. High capacity, heavy duty casters are used in many industrial applications, such as platform trucks, carts, assemblies, and tow lines in plants. Types Casters may be fixed to roll along a straight line path, or mounted on a pivot or pintle such that the wheel will automatically align itself to the direction of travel. Rigid casters A basic, rigid caster consists of a wheel mounted to a stationary fork. The orientation of the fork, which is fixed relative to the vehicle, is determined when the caster is mounted to the vehicle. An example of this is the wheels found at the rear of a shopping cart in North America. Rigid casters tend to restrict vehicle motion so that the vehicl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tailwheel
Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 133. Aviation Supplies & Academics, 1997. From the Ground Up, 27th edition, page 11 The term taildragger is also used, although some argue it should apply only to those aircraft with a tailskid rather than a wheel. The term "conventional" persists for historical reasons, but all modern jet aircraft and most modern propeller aircraft use tricycle gear. History In early aircraft, a tailskid made of metal or wood was used to support the tail on the ground. In most modern aircraft with conventional landing gear, a small articulated wheel assembly is attached to the rearmost part of the airframe in place of the skid. This wheel may be steered by the pilot through a connection to the rudder pedals, allowing the rudder ... [...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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are specially shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the water at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston Engine
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.''Thermodynamics: An Engineering Approach'' by Yunus A. Cengal and Michael A. Boles Common features in all types There may be one or more pistons. Each piston is inside a cylinder, into which a gas is i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Minor
The Walter Minor is a family of four- and six-cylinder inverted inline air-cooled engines, developed under auspices of ing. Šimůnek and used on light aircraft. First produced in 1929, the Minor engines' family has an advanced design for the period and sports steel cylinders, aluminum heads and overhead valves, with identical bore and stroke of and , respectively. Typical power ratings varied from . After Walter concentrated on the turbine powerplants only, the production of piston engines has been transferred to the Avia Avia Motors s.r.o. is a Czech automotive manufacturer. It was founded in 1919 as an aircraft maker, and diversified into trucks after 1945. As an aircraft maker it was notable for producing biplane fighter aircraft, especially the B-534. Av ... company that further developed the family, bringing fuel injection, as the Avia M-137 and M-337. Nowadays the smallest of the family, the four-cylinder carburetted Minor, is produced by a small company in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trim Tab
Trim tabs are small surfaces connected to the trailing edge of a larger control surface on a boat or aircraft, used to control the trim of the controls, i.e. to counteract hydro- or aerodynamic forces and stabilise the boat or aircraft in a particular desired attitude without the need for the operator to constantly apply a control force. This is done by adjusting the angle of the tab relative to the larger surface. Changing the setting of a trim tab adjusts the neutral or resting position of a control surface (such as an elevator or rudder). As the desired position of a control surface changes (corresponding mainly to different speeds), an adjustable trim tab will allow the operator to reduce the manual force required to maintain that position—to zero, if used correctly. Thus the trim tab acts as a servo tab. Because the center of pressure of the trim tab is farther away from the axis of rotation of the control surface than the center of pressure of the control surface, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
