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Bossi-Bonomi Pedaliante
The ''Pedaliante'' (Italian for "Pedal Glider") was a human-powered aircraft designed and built by Enea Bossi and Vittorio Bonomi and credited with, in 1936, making one of the first fully human-powered flights. The aircraft successfully traveled as part of an Italian competition, but was denied the monetary prize due to its catapult launch. History Early development In 1932, Enea Bossi heard of an airplane which had successfully flown while powered only by a engine. This prompted Bossi to calculate the minimum power that a manned aircraft would need to fly. The calculation yielded a value of approximately , which convinced Bossi that human-powered flight might be possible. During a trip to Philadelphia, Bossi tested the speed at which a glider would take off under tow. The experiment consisted of hiring a professional bicyclist to tow a glider. A spring scale was attached to the tow line to sense the force exerted by the bicyclist, the results confirming that a speed at which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human-powered Aircraft
A human-powered aircraft (HPA) is an aircraft belonging to the class of vehicles known as human-powered transport. Human-powered aircraft have been successfully flown over considerable distances. However, they are still primarily constructed as engineering challenges rather than for any kind of recreational or utilitarian purpose. History Early attempts at human-powered flight were unsuccessful because of the difficulty of achieving the high power-to-weight ratio. Prototypes often used ornithopter principles which were not only too heavy to meet this requirement but aerodynamically unsatisfactory. First attempts In 1904, Scientific American published an article and a photograph of a bicycle plane built by Steward Winslow of Riparia, Washington. He attempted to fly his plane on 30 July 1904, but one of the wheels failed. An early human-powered aircraft was the Gerhardt Cycleplane, developed by W. Frederick Gerhardt at McCook Field in Dayton, Ohio in 1923. The aircraft h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frankfurt
Frankfurt, officially Frankfurt am Main (; Hessian: , "Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on its namesake Main River, it forms a continuous conurbation with the neighboring city of Offenbach am Main and its urban area has a population of over 2.3 million. The city is the heart of the larger Rhine-Main metropolitan region, which has a population of more than 5.6 million and is Germany's second-largest metropolitan region after the Rhine-Ruhr region. Frankfurt's central business district, the Bankenviertel, lies about northwest of the geographic center of the EU at Gadheim, Lower Franconia. Like France and Franconia, the city is named after the Franks. Frankfurt is the largest city in the Rhine Franconian dialect area. Frankfurt was a city state, the Free City of Frankfurt, for nearly five centuries, and was one of the most import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spoiler (aeronautics)
In aeronautics, a spoiler (sometimes called a lift spoiler or lift dumper) is a device which intentionally reduces the lift (force), lift component of an airfoil in a controlled way. Most often, spoilers are plates on the top surface of a wing that can be extended upward into the airflow to ''spoil'' the streamline flow. By so doing, the spoiler creates a controlled Stall (flight), stall over the portion of the wing behind it, greatly reducing the lift of that wing section. Spoilers differ from air brake (aeronautics), airbrakes in that airbrakes are designed to increase drag without disrupting the lift distribution across the wing span, while spoilers disrupt the lift distribution as well as increasing drag. Spoilers fall into two categories: those that are deployed at controlled angles during flight to increase descent rate or control roll, and those that are fully deployed immediately on landing to greatly reduce lift ("lift dumpers") and increase drag. In modern fly-by- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elevator (aircraft)
Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's pitch, and therefore the angle of attack and the lift of the wing. The elevators are usually hinged to the tailplane or horizontal stabilizer. They may be the only pitch control surface present, and are sometimes located at the front of the aircraft (early airplanes) or integrated into a rear "all-moving tailplane", also called a slab elevator or stabilator. Elevator control effectiveness The elevator is a usable up and down system that controls the plane, horizontal stabilizer usually creates a ''downward'' force which balances the nose down moment created by the wing lift force, which typically applies at a point (the wing center of lift) situated aft of the airplane's center of gravity. The effects of drag and changing the engine thrust may also result in pitch moments that need to be compensated with the horizontal stabilizer. Both the horizontal stabilizer and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull (watercraft), hull or fuselage, thus imparting a turning or yaw (rotation), yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Often rudders are shaped so as to minimize Drag (physics), hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Flight Control System
A conventional Fixed-wing aircraft, fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed. The fundamentals of aircraft controls are explained in flight dynamics (fixed-wing aircraft), flight dynamics. This article centers on the operating mechanisms of the flight controls. The basic system in use on aircraft first appeared in a readily recognizable form as early as April 1908, on Louis Blériot's Blériot VIII pioneer-era monoplane design. Cockpit controls Primary controls Generally, the primary cockpit flight controls are arranged as follows:Langewiesche, WolfgangStick and Rudder: An Explanation of the Art of Flying McGraw-Hill Professional, 1990, , . * a Yoke (aircraft), control yoke (also known as a control column), centre s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length d of a diameter is also called the diameter. In this sense one speaks of diameter rather than diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r. :d = 2r \qquad\text\qquad r = \frac. For a convex shape in the plane, the diameter is defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary, and the is often defined to be the smallest such distance. Both quantities can be calculated efficiently using rotating calipers. For a curve of constant width such as the Reuleaux triangle, the width and diameter are the same because all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balsa Wood
''Ochroma pyramidale'', commonly known as the balsa tree, is a large, fast-growing tree native to the Americas. It is the sole member of the genus ''Ochroma''. The tree is famous for its wide usage in woodworking, with the name ''balsa'' being the Spanish word for "raft." A deciduous angiosperm, ''Ochroma pyramidale'' can grow up to 30 m tall, and is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood and is widely used because of its light weight. Biology Balsa on Bota Hill, Limbe Botanical Garden, Cameroon">Limbe_Botanical_Garden.html" ;"title="Bota Hill, Limbe Botanical Garden">Bota Hill, Limbe Botanical Garden, Cameroon A member of the mallow family, ''Ochroma pyramidale'' is native from southern Mexico to southern Brazil, but can now be found in many other countries (Papua New Guinea, Indonesia, Thailand, Solomon Islands). It is a pioneer plant, which establishes itself in clearings in forests, either man-made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laminate
Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials, such as plastic. A laminate is a permanently assembled object created using heat, pressure, welding, or adhesives. Various coating machines, machine presses and calendering equipment are used. Materials There are different lamination processes, depending primarily on the type or types of materials to be laminated. The materials used in laminates can be identical or different, depending on the process and the object to be laminated. Textile Laminated fabric are widely used in different fields of human activity, including medical and military. Woven fabrics (organic and inorganic based) are usually laminated by different chemical polymers to give them useful properties like chemical resistance, dust, grease, windproofness, photolumine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoplane
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing configuration and is the simplest to build. However, during the early years of flight, these advantages were offset by its greater weight and lower manoeuvrability, making it relatively rare until the 1930s. Since then, the monoplane has been the most common form for a fixed-wing aircraft. Characteristics Support and weight The inherent efficiency of the monoplane is best achieved in the cantilever wing, which carries all structural forces internally. However, to fly at practical speeds the wing must be made thin, which requires a heavy structure to make it strong and stiff enough. External bracing can be used to improve structural efficiency, reducing weight and cost. For a wing of a given size, the weight reduction allows it to fly slower a ... [...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. * Ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Nationality Law
United States nationality law details the conditions in which a person holds United States nationality. In the United States, nationality is typically obtained through provisions in the U.S. constitution, U.S. Constitution, various laws, and international agreements. Citizenship is a right, not a privilege. While the domestic documents often use citizenship and nationality interchangeably, nationality refers to the legal means in which a person obtains a national identity and formal membership in a nation and citizenship refers to the relationship held by nationals who are also citizens. Individuals born in any of the 50 U.S. states, the District of Columbia or almost any inhabited Territories of the United States, territory are Natural-born-citizen clause, natural-born United States citizens. The sole exception is American Samoa, where individuals are typically non-citizen U.S. nationals at birth. Foreign nationals living in any state or qualified territory may naturalize aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
