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Bombsight
A bombsight is a device used by military aircraft to drop bombs accurately. Bombsights, a feature of combat aircraft since World War I, were first found on purpose-designed bomber aircraft and then moved to fighter-bombers and modern tactical aircraft as those aircraft took up the brunt of the bombing role. A bombsight has to estimate the path the bomb will take after release from the aircraft. The two primary forces during its fall are gravity and air drag, which make the path of the bomb through the air roughly parabolic. There are additional factors such as changes in air density and wind that may be considered, but they are concerns only for bombs that spend a significant portion of a minute falling through the air. Those effects can be minimized by reducing the fall time by low-level bombing or by increasing the speed of the bombs. Those effects are combined in the dive bomber. However, low-level bombing also increases the danger to the bomber from ground-based defe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norden Bombsight
The Norden Mk. XV, known as the Norden M series in U.S. Army service, is a bombsight that was used by the United States Army Air Forces (USAAF) and the United States Navy during World War II, and the United States Air Force in the Korean War, Korean and the Vietnam Wars. It was an early Bombsight#Tachometric bombsights, tachometric design, which combined optics, a mechanical computer, and an autopilot for the first time to not merely identify a target but fly the airplane to it. The bombsight directly measured the aircraft's ground speed and direction, which older types could only estimate with lengthy manual procedures. The Norden further improved on older designs by using an analog computer that continuously recalculated the bomb's impact point based on changing flight conditions, and an autopilot that reacted quickly and accurately to changes in the wind or other effects. Together, these features promised unprecedented accuracy for daytime bombing from high altitudes. During ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bombsight
A bombsight is a device used by military aircraft to drop bombs accurately. Bombsights, a feature of combat aircraft since World War I, were first found on purpose-designed bomber aircraft and then moved to fighter-bombers and modern tactical aircraft as those aircraft took up the brunt of the bombing role. A bombsight has to estimate the path the bomb will take after release from the aircraft. The two primary forces during its fall are gravity and air drag, which make the path of the bomb through the air roughly parabolic. There are additional factors such as changes in air density and wind that may be considered, but they are concerns only for bombs that spend a significant portion of a minute falling through the air. Those effects can be minimized by reducing the fall time by low-level bombing or by increasing the speed of the bombs. Those effects are combined in the dive bomber. However, low-level bombing also increases the danger to the bomber from ground-based defe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boeing B-17
The Boeing B-17 Flying Fortress is an American four-engined heavy bomber aircraft developed in the 1930s for the United States Army Air Corps (USAAC). A fast and high-flying bomber, the B-17 dropped more bombs than any other aircraft during World War II, used primarily in the European Theater of Operations, United States Army, European Theater of Operations. It is the List of most-produced aircraft, third-most produced bomber in history, behind the American four-engined Consolidated B-24 Liberator and the German multirole, twin-engined Junkers Ju 88. The B-17 was also employed in transport, anti-submarine warfare, and search and rescue roles. In a USAAC competition, Boeing, Boeing's prototype Model 299/XB-17 outperformed two other entries but crashed, losing the initial 200-bomber contract to the Douglas B-18 Bolo. Still, the Air Corps ordered 13 more B-17s for further evaluation, which were introduced into service in 1938. The B-17 evolved through numerous Boeing B-17 Flyin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dive Bomber
A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact throughout the bomb run. This allows attacks on point targets and ships, which were difficult to attack with conventional level bombers, even ''en masse''. Dive bombing was especially effective against vehicles when integrated into early instances of Blitzkrieg. After World War II, the rise of precision-guided munitions and improved anti-aircraft defences—both fixed gunnery positions and fighter interception—led to a fundamental change in dive bombing. New weapons, such as rockets, allowed for better accuracy from smaller dive angles and from greater distances. They could be fitted to almost any aircraft, including fighters, improving their effectiveness without the inherent vulnerabilities of dive bombers, which needed air superiority to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Computer
A mechanical computer is a computer built from mechanical components such as levers and gears rather than electronic components. The most common examples are adding machines and mechanical counters, which use the turning of gears to increment output displays. More complex examples could carry out multiplication and division—Friden used a moving head which paused at each column—and even differential analysis. One model, the Ascota 170 accounting machine sold in the 1960s, calculated square roots. Mechanical computers reached their zenith during World War II, when they formed the basis of complex bombsights including the Norden, as well as the similar devices for ship computations such as the US Torpedo Data Computer or British Admiralty Fire Control Table. Noteworthy are mechanical flight instruments for early spacecraft, which provided their computed output not in the form of digits, but through the displacements of indicator surfaces. From Yuri Gagarin's first s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head-up Display
A head-up display, or heads-up display, also known as a HUD () or head-up guidance system (HGS), is any transparent display that presents data without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view information with the head positioned "up" and looking forward, instead of angled down looking at lower instruments. A HUD also has the advantage that the pilot's eyes do not need to refocus to view the outside after looking at the optically nearer instruments. Although they were initially developed for military aviation, HUDs are now used in commercial aircraft, automobiles, and other (mostly professional) applications. Head-up displays were a precursor technology to augmented reality (AR), incorporating a subset of the features needed for the full AR experience, but lacking the necessary registration and tracking between the virtual content and the user's real-world environment. Overview A typical HUD cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bomber Aircraft
A bomber is a military combat aircraft that utilizes air-to-ground weaponry to drop bombs, launch torpedoes, or deploy air-launched cruise missiles. There are two major classifications of bomber: strategic and tactical. Strategic bombing is done by heavy bombers primarily designed for long-range bombing missions against strategic targets to diminish the enemy's ability to wage war by limiting access to resources through crippling infrastructure, reducing industrial output, or inflicting massive civilian casualties to an extent deemed to force surrender. Tactical bombing is aimed at countering enemy military activity and in supporting offensive operations, and is typically assigned to smaller aircraft operating at shorter ranges, typically near the troops on the ground or against enemy shipping. Bombs were first dropped from an aircraft during the Italo-Turkish War, with the first major deployments coming in the First World War and Second World War by all major airforces, dama ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Velocity
Terminal velocity is the maximum speed attainable by an object as it falls through a fluid (air is the most common example). It is reached when the sum of the drag force (''Fd'') and the buoyancy is equal to the downward force of gravity (''FG'') acting on the object. Since the net force on the object is zero, the object has zero acceleration. For objects falling through air at normal pressure, the buoyant force is usually dismissed and not taken into account, as its effects are negligible. As the speed of an object increases, so does the drag force acting on it, which also depends on the substance it is passing through (for example air or water). At some speed, the drag or force of resistance will be equal to the gravitational pull on the object. At this point the object stops accelerating and continues falling at a constant speed called the terminal velocity (also called settling velocity). An object moving downward faster than the terminal velocity (for example because it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of Attack
In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a Airfoil#Airfoil terminology, reference line on a body (often the chord (aircraft), chord line of an airfoil) and the vector (geometry), vector representing the relative motion between the body and the fluid through which it is moving. Angle of attack is the angle between the body's reference line and the oncoming flow. This article focuses on the most common application, the angle of attack of a wing or airfoil moving through air. In aerodynamics, angle of attack specifies the angle between the chord line of the wing of a fixed-wing aircraft and the vector representing the relative motion between the aircraft and the atmosphere. Since a wing can have twist, a chord line of the whole wing may not be definable, so an alternate reference line is simply defined. Often, the chord line of the Wing root, root of the wing is chosen as the reference line. Another choice is to use a horizontal line on the fuse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity. Drag force is proportional to the relative velocity for low-speed flow and is proportional to the velocity squared for high-speed flow. This distinction between low and high-speed flow is measured by the Reynolds number. Drag is instantaneously related to vorticity dynamics through the Josephson-Anderson relation. Examples Examples of drag include: * Net force, Net Aerodynamic force, aerodynamic or Fluid dynamics, hydrodynamic force: Drag acting opposite to the direction of movement of a solid object such as cars, aircraft, and boat hulls. * Viscou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Momentum
In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. If is an object's mass and is its velocity (also a vector quantity), then the object's momentum (from Latin '' pellere'' "push, drive") is: \mathbf = m \mathbf. In the International System of Units (SI), the unit of measurement of momentum is the kilogram metre per second (kg⋅m/s), which is dimensionally equivalent to the newton-second. Newton's second law of motion states that the rate of change of a body's momentum is equal to the net force acting on it. Momentum depends on the frame of reference, but in any inertial frame of reference, it is a ''conserved'' quantity, meaning that if a closed system is not affected by external forces, its total momentum does not change. Momentum is also conserved in special relativity (with a mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
