The Boeing B-29 Superfortress is a United States Army Air Forces long range, strategic heavy bomber that was produced in many experimental and production models from 1943 to 1946.
121-609: The XB-29 , Boeing Model 345, was the first accepted prototype or experimental model delivered to the Army Air Corps , incorporating a number of improvements on the design originally submitted, including more and larger guns and self-sealing fuel tanks . Two aircraft were ordered in August 1940, and a third was ordered in December. A mockup was completed in the spring of 1941, and it first flew on September 21, 1942. Testing
242-639: A mockup , which is an inert representation of a machine's appearance, often made of some non-durable substance. An electronics designer often builds the first prototype from breadboard or stripboard or perfboard , typically using "DIP" packages. However, more and more often the first functional prototype is built on a "prototype PCB " almost identical to the production PCB, as PCB manufacturing prices fall and as many components are not available in DIP packages, but only available in SMT packages optimized for placing on
363-522: A second (thus defining the speed of light to be 299,792,458 meters per second). In many sciences, from pathology to taxonomy, prototype refers to a disease, species, etc. which sets a good example for the whole category. In biology, prototype is the ancestral or primitive form of a species or other group; an archetype. For example, the Senegal bichir is regarded as the prototypes of its genus, Polypterus . Flak Anti-aircraft warfare
484-600: A 75 mm 12-pounder, and even a 105 mm gun. Erhardt also had a 12-pounder, while Vickers Maxim offered a 3-pounder and Schneider a 47 mm. The French balloon gun appeared in 1910, it was an 11-pounder but mounted on a vehicle, with a total uncrewed weight of two tons. However, since balloons were slow moving, sights were simple. But the challenges of faster moving aeroplanes were recognised. By 1913 only France and Germany had developed field guns suitable for engaging balloons and aircraft and addressed issues of military organisation. Britain's Royal Navy would soon introduce
605-425: A PCB. Builders of military machines and aviation prefer the terms "experimental" and "service test". In electronics , prototyping means building an actual circuit to a theoretical design to verify that it works, and to provide a physical platform for debugging it if it does not. The prototype is often constructed using techniques such as wire wrapping or using a breadboard , stripboard or perfboard , with
726-529: A favorite among US Military modelers), railroad equipment, motor trucks, motorcycles, and space-ships (real-world such as Apollo/Saturn Vs, or the ISS). As of 2014, basic rapid prototype machines (such as 3D printers ) cost about $ 2,000, but larger and more precise machines can cost as much as $ 500,000. In architecture , prototyping refers to either architectural model making (as form of scale modelling ) or as part of aesthetic or material experimentation , such as
847-645: A full military structure. For example, the UK's Anti-Aircraft Command, commanded by a full British Army general was part of ADGB. At its peak in 1941–42 it comprised three AA corps with 12 AA divisions between them. The use of balloons by the U.S. Army during the American Civil War compelled the Confederates to develop methods of combating them. These included the use of artillery, small arms, and saboteurs. They were unsuccessful, and internal politics led
968-451: A large traverse that could be easily transported on a wagon. Krupp 75 mm guns were supplied with an optical sighting system that improved their capabilities. The German Army also adapted a revolving cannon that came to be known to Allied fliers as the " flaming onion " from the shells in flight. This gun had five barrels that quickly launched a series of 37 mm artillery shells. As aircraft started to be used against ground targets on
1089-543: A maritime force against attacks by airborne weapons launched from aircraft, ships, submarines and land-based sites". In some armies the term all-arms air defence (AAAD) is used for air defence by nonspecialist troops. Other terms from the late 20th century include "ground based air defence" (GBAD) with related terms " short range air defense " (SHORAD) and man-portable air-defense system (MANPADS). Anti-aircraft missiles are variously called surface-to-air missiles , ("SAMs") and surface-to-air guided weapons (SAGWs). Examples are
1210-600: A modified aircraft to show that it could still be used if the R-3350 development was not successful. Since the R-3350 did not have significant enough problems to prevent its use, no XB-39s were ordered. In 1945, three B-29s were forced to land in Soviet territory after a bombing raid on Japan because of lack of fuel. Since the Soviet Union was not at war with Japan at the time, the aircraft and crew were interned. Eventually,
1331-513: A new 3.6-inch gun, in 1918. In 1928 a 3.7-inch (94 mm) gun became the preferred solution, but it took six years to gain funding. Production of the QF 3.7-inch gun began in 1937; this gun was used on mobile carriages with the field army and transportable guns on fixed mountings for static positions. At the same time the Royal Navy adopted a new 4.5-inch (113 mm) gun in a twin turret, which
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#17327724916081452-637: A new field mounting was introduced in 1916. Since most attacks were at night, searchlights were soon used, and acoustic methods of detection and locating were developed. By December 1916 there were 183 AA sections defending Britain (most with the 3-inch), 74 with the BEF in France and 10 in the Middle East. AA gunnery was a difficult business. The problem was of successfully aiming a shell to burst close to its target's future position, with various factors affecting
1573-630: A par with the army, navy, or air force. In the Soviet Union, this was called Voyska PVO , and had both fighter aircraft, separate from the air force, and ground-based systems. This was divided into two arms, PVO Strany, the Strategic Air defence Service responsible for Air Defence of the Homeland, created in 1941 and becoming an independent service in 1954, and PVO SV, Air Defence of the Ground Forces. Subsequently, these became part of
1694-422: A real, working system rather than a theoretical one. Physical prototyping has a long history, and paper prototyping and virtual prototyping now extensively complement it. In some design workflow models, creating a prototype (a process sometimes called materialization ) is the step between the formalization and the evaluation of an idea. A prototype can also mean a typical example of something such as in
1815-499: A time to the initial prototype. In many programming languages , a function prototype is the declaration of a subroutine or function (and should not be confused with software prototyping). This term is rather C / C++ -specific; other terms for this notion are signature , type and interface . In prototype-based programming (a form of object-oriented programming ), new objects are produced by cloning existing objects, which are called prototypes. The term may also refer to
1936-472: A way that the Planck constant h is prescribed a value of exactly 6.626 070 15 × 10 joule-second (J⋅s) Until 1960, the meter was defined by a platinum-iridium prototype bar with two marks on it (that were, by definition, spaced apart by one meter), the international prototype of the metre , and in 1983 the meter was redefined to be the distance in free space covered by light in 1/299,792,458 of
2057-518: Is a form of functional or working prototype. The justification for its creation is usually a data migration , data integration or application implementation project and the raw materials used as input are an instance of all the relevant data which exists at the start of the project. The objectives of data prototyping are to produce: To achieve this, a data architect uses a graphical interface to interactively develop and execute transformation and cleansing rules using raw data. The resultant data
2178-483: Is assisted but not governed by identification friend or foe (IFF) electronic devices originally introduced during the Second World War . While these rules originate at the highest authority, different rules can apply to different types of air defence covering the same area at the same time. AAAD usually operates under the tightest rules. NATO calls these rules "weapon control orders" (WCO), they are: Until
2299-517: Is becoming practical to eliminate the creation of a physical prototype (except possibly at greatly reduced scales for promotional purposes), instead modeling all aspects of the final product as a computer model . An example of such a development can be seen in Boeing 787 Dreamliner , in which the first full sized physical realization is made on the series production line. Computer modeling is now being extensively used in automotive design, both for form (in
2420-639: Is deployed in several ways: Air defence has included other elements, although after the Second World War most fell into disuse: Passive air defence is defined by NATO as "Passive measures taken for the physical defence and protection of personnel, essential installations and equipment in order to minimise the effectiveness of air and/or missile attack". It remains a vital activity by ground forces and includes camouflage and concealment to avoid detection by reconnaissance and attacking aircraft. Measures such as camouflaging important buildings were common in
2541-454: Is operated by specialists, batteries may have several dozen teams deploying separately in small sections; self-propelled air defence guns may deploy in pairs. Batteries are usually grouped into battalions or equivalent. In the field army, a light gun or SHORAD battalion is often assigned to a manoeuvre division. Heavier guns and long-range missiles may be in air-defence brigades and come under corps or higher command. Homeland air defence may have
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#17327724916082662-462: Is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action". It encompasses surface-based, subsurface ( submarine-launched ), and air-based weapon systems, in addition to associated sensor systems, command and control arrangements, and passive measures (e.g. barrage balloons ). It may be used to protect naval , ground , and air forces in any location. However, for most countries,
2783-414: Is then evaluated and the rules refined. Beyond the obvious visual checking of the data on-screen by the data architect, the usual evaluation and validation approaches are to use Data profiling software and then to insert the resultant data into a test version of the target application and trial its use. When developing software or digital tools that humans interact with, a prototype is an artifact that
2904-414: Is to detect hostile aircraft and destroy them. The critical issue is to hit a target moving in three-dimensional space; an attack must not only match these three coordinates, but must do so at the time the target is at that position. This means that projectiles either have to be guided to hit the target, or aimed at the predicted position of the target at the time the projectile reaches it, taking into account
3025-499: Is used as the standard of measurement of some physical quantity to base all measurement of that physical quantity against. Sometimes this standard object is called an artifact . In the International System of Units ( SI ), there remains no prototype standard since May 20, 2019 . Before that date, the last prototype used was the international prototype of the kilogram , a solid platinum-iridium cylinder kept at
3146-409: Is used to ask and answer a design question. Prototypes provide the means for examining design problems and evaluating solutions. HCI practitioners can employ several different types of prototypes: In the field of scale modeling (which includes model railroading , vehicle modeling, airplane modeling , military modeling, etc.), a prototype is the real-world basis or source for a scale model—such as
3267-586: Is usually accomplished via the combined use of systems optimized for either short-, medium-, or long-range air defence. In some countries, such as Britain and Germany during the Second World War , the Soviet Union , and modern NATO and the United States, ground-based air defence and air defence aircraft have been under integrated command and control. However, while overall air defence may be for homeland defence (including military facilities), forces in
3388-425: The 13-pr QF 9 cwt and these proved much more satisfactory. However, in general, these ad hoc solutions proved largely useless. With little experience in the role, no means of measuring target, range, height or speed the difficulty of observing their shell bursts relative to the target gunners proved unable to get their fuse setting correct and most rounds burst well below their targets. The exception to this rule
3509-524: The B-50 , which served throughout the 1950s in the U.S. bomber fleet. A number of B-29s were converted to serve as test beds for new systems. These all received variant designation, even though many existed only as a single converted aircraft. The XB-29E for fire-control systems (one converted) was a model B-29-45-BW. The B-29F for cold-weather operation in Alaska were six converted B-29-BWs. The B-29
3630-594: The Bureau International des Poids et Mesures (International Bureau of Weights and Measures) in Sèvres France (a suburb of Paris ) that by definition was the mass of exactly one kilogram . Copies of this prototype are fashioned and issued to many nations to represent the national standard of the kilogram and are periodically compared to the Paris prototype. Now the kilogram is redefined in such
3751-655: The F-13/FB-29 s were redesignated RB-29 and RB-29A . Six B-29A/F-13As were modified with the Wright R-3350-CA-2 fuel injected engines and designated at YB-29J s. These were then converted to RB-29J s. In January 1949, RB-29s were assigned to the 91st Strategic Reconnaissance Wing and moved to Yokota AB , Japan in December 1950; to provide support to the Korean War and attached to the 15th Air Force , Far East Air Force . The SB-29 'Super Dumbo'
Boeing B-29 Superfortress variants - Misplaced Pages Continue
3872-528: The Forty Wall House open source material prototyping centre in Australia. Architects prototype to test ideas structurally, aesthetically and technically. Whether the prototype works or not is not the primary focus: architectural prototyping is the revelatory process through which the architect gains insight. In the science and practice of metrology , a prototype is a human-made object that
3993-536: The Prototype Javascript Framework . Additionally, the term may refer to the prototype design pattern. Continuous learning approaches within organizations or businesses may also use the concept of business or process prototypes through software models. The concept of prototypicality is used to describe how much a website deviates from the expected norm, and leads to a lowering of user preference for that site's design. A data prototype
4114-463: The QF 3-inch and QF 4-inch AA guns and also had Vickers 1-pounder quick firing "pom-poms" that could be used in various mountings. The first US anti-aircraft cannon was a 1-pounder concept design by Admiral Twining in 1911 to meet the perceived threat of airships, that eventually was used as the basis for the US Navy's first operational anti-aircraft cannon: the 3-inch/23 caliber gun . On
4235-671: The RIM-66 Standard , Raytheon Standard Missile 6 , or the MBDA Aster missile. Non-English terms for air defence include the German Flak or FlaK ( Fliegerabwehrkanone , 'aircraft defence cannon', also cited as Flugabwehrkanone ), whence English flak , and the Russian term Protivovozdushnaya oborona ( Cyrillic : Противовозду́шная оборо́на), a literal translation of 'anti-air defence', abbreviated as PVO. In Russian,
4356-675: The Royal Naval Volunteer Reserve (RNVR) was manning AA guns and searchlights assembled from various sources at some nine ports. The Royal Garrison Artillery (RGA) was given responsibility for AA defence in the field, using motorised two-gun sections. The first were formally formed in November 1914. Initially they used QF 1-pounder "pom-pom"s (37 mm versions of the Maxim Gun ). All armies soon deployed AA guns often based on their smaller field pieces, notably
4477-520: The UK over the Atlantic. They were also used to fly into the eye of a hurricane or typhoon to gather information. Following nuclear weapons tests, some WB-29s used air sampling scoops to test radiation levels. On 3 September 1949, a WB-29 returning from Yokota AB , Japan, to Eielson AFB , Alaska, recovered radioactive debris in air sampling scoops from the cloud generated by the first atomic bomb test by
4598-682: The United States Air Force 's operating bases in the UK. All ground-based air defence was removed from Royal Air Force (RAF) jurisdiction in 2004 . The British Army's Anti-Aircraft Command was disbanded in March 1955, but during the 1960s and 1970s the RAF's Fighter Command operated long-range air-defence missiles to protect key areas in the UK. During World War II, the Royal Marines also provided air defence units; formally part of
4719-643: The XXI Bomber Command — felt that a (lighter) faster bomber would better evade Japanese flak . In the B-29B, as with the atomic raid-dedicated Silverplate versions earlier, all defensive armament was removed except for that in the tail turret. Initially the armament was two .50 in AN/M2 machine guns and one 20 mm M2 cannon which was soon changed to three .50 in AN/M2s. The weight saved by removing
4840-421: The styling and aerodynamics of the vehicle) and in function—especially for improving vehicle crashworthiness and in weight reduction to improve mileage. The most common use of the word prototype is a functional, although experimental, version of a non-military machine (e.g., automobiles, domestic appliances, consumer electronics) whose designers would like to have built by mass production means, as opposed to
4961-649: The 1950s, guns firing ballistic munitions were the standard weapon; guided missiles then became dominant, except at the very shortest ranges. However, the type of shell or warhead and its fuzing and, with missiles, the guidance arrangement were and are varied. Targets are not always easy to destroy; nonetheless, damaged aircraft may be forced to abort their mission and, even if they manage to return and land in friendly territory, may be out of action for days or permanently. Ignoring small arms and smaller machine-guns, ground-based air defence guns have varied in calibre from 20 mm to at least 152 mm. Ground-based air defence
Boeing B-29 Superfortress variants - Misplaced Pages Continue
5082-471: The 30th of September, 1915, troops of the Serbian Army observed three enemy aircraft approaching Kragujevac . Soldiers fired at them with shotguns and machine-guns but failed to prevent them from dropping 45 bombs over the city, hitting military installations, the railway station and many other, mostly civilian, targets in the city. During the bombing raid, private Radoje Ljutovac fired his cannon at
5203-420: The 8.8 cm FlaK 18 in 1933, the 36 and 37 models followed with various improvements, but ballistic performance was unchanged. In the late 1930s the 10.5 cm FlaK 38 appeared, soon followed by the 39; this was designed primarily for static sites but had a mobile mounting, and the unit had 220 V 24 kW generators. In 1938 design started on the 12.8 cm FlaK . Britain had successfully tested
5324-487: The AA systems are called zenitnye (i.e., 'pointing to zenith ') systems. In French, air defence is called Défense contre les aéronefs (DCA) , aéronef meaning 'aircraft'. The maximum distance at which a gun or missile can engage an aircraft is an important figure. However, many different definitions are used and unless the same definition is used, performance of different guns or missiles cannot be compared. For AA guns only
5445-790: The B-29 crew members were returned, but the aircraft remained in Russian hands. Seeking a modern long-range bomber, Joseph Stalin ordered the Tupolev OKB to reverse-engineer the Superfortress. The resulting aircraft first flew on May 19, 1947, and immediately began series production, totalling 847 Tu-4s. Although largely identical in appearance to American B-29s, the Tu-4 ( NATO reporting name : "Bull") had Soviet-designed defensive guns and had been re-engineered to suit production using material of metric thicknesses, resulting in an aircraft that
5566-608: The B-29 program, issuing a scathing report, prompting the Army Air Forces to take control of the program. The YB-29 was an improved XB-29 and 14 were built for service testing. Testing began in the summer of 1943, and dozens of modifications were made to the planes. The engines were upgraded from Wright R-3350 -13s to R-3350-21s. Where the XB-29 had three-bladed props, the YB-29 had four-bladed propellers. Various alternatives to
5687-605: The B-29, the Tu-4 , was used as the platform for a Chinese experimental airborne early warning aircraft, the KJ-1 AEWC , in the 1970s. A study for the conversion of B-29s to long-range cruise missiles was conducted by the Air Materiel Command between 1946 and 1950; given the designation MX-767, it was given the codename Project Banshee. Flight tests were conducted, however no full conversions were carried out before
5808-492: The British Isles increased in 1915 and the AA efforts were deemed somewhat ineffective, so a Royal Navy gunnery expert, Admiral Sir Percy Scott , was appointed to make improvements, particularly an integrated AA defence for London. The air defences were expanded with more RNVR AA guns, 75 mm and 3-inch, the pom-poms being ineffective. The naval 3-inch was also adopted by the army, the QF 3-inch 20 cwt (76 mm),
5929-546: The British adopted a new instrument developed by Vickers. It was a mechanical analogue computer - the Predictor AA No 1. Given the target height, its operators tracked the target and the predictor produced bearing, quadrant elevation and fuse setting. These were passed electrically to the guns, where they were displayed on repeater dials to the layers who "matched pointers" (target data and the gun's actual data) to lay
6050-472: The French 75 mm and Russian 76.2 mm, typically simply propped up on some sort of embankment to get the muzzle pointed skyward. The British Army adopted the 13-pounder quickly producing new mountings suitable for AA use, the 13-pdr QF 6 cwt Mk III was issued in 1915. It remained in service throughout the war but 18-pdr guns were lined down to take the 13-pdr shell with a larger cartridge producing
6171-563: The German Flugzeugabwehrkanone ), "ack-ack" (from the spelling alphabet used by the British for voice transmission of "AA"); and "archie" (a World War I British term probably coined by Amyas Borton , and believed to derive via the Royal Flying Corps , from the music-hall comedian George Robey 's line "Archibald, certainly not!" ). NATO defines anti-aircraft warfare (AAW) as "measures taken to defend
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#17327724916086292-473: The Second World War. During the Cold War the runways and taxiways of some airfields were painted green. While navies are usually responsible for their own air defence—at least for ships at sea—organisational arrangements for land-based air defence vary between nations and over time. The most extreme case was the Soviet Union and this model may still be followed in some countries: it was a separate service, on
6413-599: The Soviet Union on 29 August. In 1951, three B-29s were modified for use in the Airborne Early Warning program . The upper section of the forward fuselage was extensively modified to house an AN/APS-20 C search radar, and the interior was modified to house radar and Electronic Counter Measures (ECM) equipment. This development led to production radar picket aircraft, including the EC-121 Warning Star . (×3, converted) A Soviet-built copy of
6534-508: The Tu-4 airframe in the KJ-1 AWACS aircraft. Prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics , design , electronics , and software programming . A prototype is generally used to evaluate a new design to enhance precision by system analysts and users. Prototyping serves to provide specifications for
6655-621: The United States Army's Balloon Corps to be disbanded mid-war. The Confederates experimented with balloons as well. Turks carried out the first ever anti-airplane operation in history during the Italo-Turkish war . Although lacking anti-aircraft weapons, they were the first to shoot down an airplane by rifle fire. The first aircraft to crash in a war was the one of Lieutenant Piero Manzini, shot down on August 25, 1912. The earliest known use of weapons specifically made for
6776-669: The air force and ground forces respectively. At the other extreme, the United States Army has an Air Defense Artillery Branch that provides ground-based air defence for both homeland and the army in the field; however, it is operationally under the Joint Force Air Component Commander . Many other nations also deploy an air-defence branch in the army. Some, such as Japan or Israel, choose to integrate their ground based air defence systems into their air force. In Britain and some other armies,
6897-682: The aircraft, unable to climb, crashed into the Frye meat-packing plant. The crash demolished the majority of the packing plant and killed all eleven XB-29 crew, 22 employees at the plant, and one fireman. Many leading Boeing personnel involved in the design perished in the accident; the pilot, Allen, was chief of the Research Division. After the crash, the United States Army Air Forces and a congressional committee headed by then- Senator Harry S. Truman investigated
7018-413: The altitude at which a gun could deliver a series of shells against a moving target; this could be constrained by maximum fuse running time as well as the gun's capability. By the late 1930s the British definition was "that height at which a directly approaching target at 400 mph [640 km/h] can be engaged for 20 seconds before the gun reaches 70 degrees elevation". The essence of air defence
7139-562: The anti-aircraft role occurred during the Franco-Prussian War of 1870. After the disaster at Sedan , Paris was besieged and French troops outside the city started an attempt at communication via balloon . Gustav Krupp mounted a modified 1-pounder (37 mm) gun – the Ballonabwehrkanone (Balloon defence cannon) or BaK — on top of a horse-drawn carriage for the purpose of shooting down these balloons. By
7260-407: The ascending part of the trajectory can be usefully used. One term is "ceiling", the maximum ceiling being the height a projectile would reach if fired vertically, not practically useful in itself as few AA guns are able to fire vertically, and the maximum fuse duration may be too short, but potentially useful as a standard to compare different weapons. The British adopted "effective ceiling", meaning
7381-457: The battlefield, the AA guns could not be traversed quickly enough at close targets and, being relatively few, were not always in the right place (and were often unpopular with other troops), so changed positions frequently. Soon the forces were adding various machine-gun based weapons mounted on poles. These short-range weapons proved more deadly, and the " Red Baron " is believed to have been shot down by an anti-aircraft Vickers machine gun . When
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#17327724916087502-408: The competition for a share of limited defence budgets. Demobilisation meant that most AA guns were taken out of service, leaving only the most modern. However, there were lessons to be learned. In particular the British, who had had AA guns in most theatres in action in daylight and used them against night attacks at home. Furthermore, they had also formed an Anti-Aircraft Experimental Section during
7623-407: The cycle returns to customer evaluation. The cycle starts by listening to the user, followed by building or revising a mock-up, and letting the user test the mock-up , then back. There is now a new generation of tools called Application Simulation Software which help quickly simulate application before their development. Extreme programming uses iterative design to gradually add one feature at
7744-441: The designation included B-29s modified solely for that purpose. Their most important role was serving as radar targets in the 1950s when the United States Air Force was developing intercept tactics for its fighters. The WB-29 s were production aircraft modified to perform weather monitoring missions. An observation position was fitted above the central fuselage section. They conducted standard data-gathering flights, including from
7865-582: The disassembled aircraft, awaiting future restoration to flyable status. BuNo 84030 and 84031 were later modified into anti-submarine patrol bombers and redesignated P2B-2S. The XB-39 Superfortress was a single YB-29 modified to use water-cooled Allison V-3420 -17 Vee type engines. Since the Army Air Force was concerned that problems might develop with their first choice of engine, the Wright R-3350 , they contracted General Motors to test
7986-631: The early 1960s, being replaced by more modern aircraft such as the Tupolev Tu-95 . Although the Tu-4 had never delivered any explosive payload with offensive intent, it influenced Soviet aircraft technology, particularly airframe construction and onboard systems. Advanced transport and bomber variants of the Tu-4 design such as the Tu-70 , Tu-75 , Tu-80 , and Tu-85 , were developed and built, but none of these achieved series production. The People's Liberation Army Air Force of China attempted to use
8107-678: The early 20th century balloon, or airship, guns, for land and naval use were attracting attention. Various types of ammunition were proposed, high explosive, incendiary, bullet-chains, rod bullets and shrapnel. The need for some form of tracer or smoke trail was articulated. Fuzing options were also examined, both impact and time types. Mountings were generally pedestal type but could be on field platforms. Trials were underway in most countries in Europe but only Krupp, Erhardt, Vickers Maxim, and Schneider had published any information by 1910. Krupp's designs included adaptations of their 65 mm 9-pounder,
8228-490: The enemy aircraft and successfully shot one down. It crashed in the city and both pilots died from their injuries. The cannon Ljutovac used was not designed as an anti-aircraft gun; it was a slightly modified Turkish cannon captured during the First Balkan War in 1912. This was the first occasion in military history that a military aircraft was shot down with ground-to-air artillery fire. The British recognised
8349-654: The field, wherever they are, provide their own defences against airborne threats. Until the 1950s, guns firing ballistic munitions ranging from 7.62 mm (.30 in) to 152.4 mm (6 in) were the standard weapons; guided missiles then became dominant, except at the very shortest ranges (as with close-in weapon systems , which typically use rotary autocannons or, in very modern systems, surface-to-air adaptations of short-range air-to-air missiles , often combined in one system with rotary cannons). It may also be called counter-air , anti-air , AA , flak , layered air defence or air defence forces . The term air defence
8470-480: The final production costs due to inefficiencies in materials and processes. Prototypes are also used to revise the design for the purposes of reducing costs through optimization and refinement. It is possible to use prototype testing to reduce the risk that a design may not perform as intended, however prototypes generally cannot eliminate all risk. Building the full design is often expensive and can be time-consuming, especially when repeated several times—building
8591-528: The final production design. This is due to the skill and choices of the designer(s), and the inevitable inherent limitations of a prototype. Due to differences in materials, processes and design fidelity, it is possible that a prototype may fail to perform acceptably although the production design may have been sound. Conversely, prototypes may perform acceptably but the production design and outcome may prove unsuccessful. In general, it can be expected that individual prototype costs will be substantially greater than
8712-540: The forward dorsal turrets was doubled to four beginning with production block 20. Where the wings of previous models had been made by the sub-assembly of two sections, the B-29A wing was built up from three. This made construction easier, and increased the strength of the airframe. The B-29A was produced until May 1946, when the last aircraft was completed. It was employed up to, and through, the Korean War , after which it
8833-464: The full design, figuring out what the problems are and how to solve them, then building another full design. As an alternative, rapid prototyping or rapid application development techniques are used for the initial prototypes, which implement part, but not all, of the complete design. This allows designers and manufacturers to rapidly and inexpensively test the parts of the design that are most likely to have problems, solve those problems, and then build
8954-508: The full design. In technology research, a technology demonstrator is a prototype serving as proof-of-concept and demonstration model for a new technology or future product, proving its viability and illustrating conceivable applications. In large development projects, a testbed is a platform and prototype development environment for rigorous experimentation and testing of new technologies, components, scientific theories and computational tools. With recent advances in computer modeling it
9075-584: The ground-based air defence of the British Army's Anti-Aircraft Command , although field-deployed air defence relied on less sophisticated arrangements. NATO later called these arrangements an "air defence ground environment", defined as "the network of ground radar sites and command and control centres within a specific theatre of operations which are used for the tactical control of air defence operations". Rules of engagement are critical to prevent air defences engaging friendly or neutral aircraft. Their use
9196-699: The guns increased the top speed from 357 mph to 364 mph (575 km/h to 586 km/h). Also incorporated on this version was an improved APQ-7 "Eagle" bombing-through-overcast radar that was fitted in an airfoil-shaped radome under the fuselage. All 311 B-29Bs were built at the Bell plant in Marietta, Georgia ("Bell-Atlanta"). The B-29C was a modification of the B-29A re-engined with improved Wright R-3350 Duplex-Cyclone engines. The Army Air Force originally ordered 5,000, but cancelled its request when World War II ended and none were built. The B-29D
9317-587: The guns. This system of repeater electrical dials built on the arrangements introduced by British coast artillery in the 1880s, and coast artillery was the background of many AA officers. Similar systems were adopted in other countries and for example the later Sperry M3A3 in the US, was also used by Britain as the Predictor AA No 2. Height finders were also increasing in size; in Britain, the seven-foot optical base World War I Barr & Stroud UB 2 stereoscopic rangefinder
9438-475: The impact of these differences on the intended role for the prototype. For example, if a visual prototype is not able to use the same materials as the final product, they will attempt to substitute materials with properties that closely simulate the intended final materials. Engineers and prototyping specialists seek to understand the limitations of prototypes to exactly simulate the characteristics of their intended design. Prototypes represent some compromise from
9559-501: The late 1930s for development work on sound-locating acoustic devices to be generally halted, although equipment was retained. Furthermore, in Britain the volunteer Observer Corps formed in 1925 provided a network of observation posts to report hostile aircraft flying over Britain. Initially radar was used for airspace surveillance to detect approaching hostile aircraft. However, the German Würzburg radar put into use in 1940
9680-601: The main effort has tended to be homeland defence . Missile defence is an extension of air defence, as are initiatives to adapt air defence to the task of intercepting any projectile in flight. Most modern anti-aircraft (AA) weapons systems are optimized for short-, medium-, or long-range air defence, although some systems may incorporate multiple weapons (such as both autocannons and surface-to-air missiles ). ‘Layered air defence’ usually refers to multiple ‘tiers’ of air defence systems which, when combined, an airborne threat must penetrate in order to reach its target; This defence
9801-513: The mobile naval base defence organisation, they were handled as an integral part of the army-commanded ground based air defences. The basic air defence unit is typically a battery with 2 to 12 guns or missile launchers and fire control elements. These batteries, particularly with guns, usually deploy in a small area, although batteries may be split; this is usual for some missile systems. SHORAD missile batteries often deploy across an area with individual launchers several kilometres apart. When MANPADS
9922-494: The need for anti-aircraft capability a few weeks before World War I broke out; on 8 July 1914, the New York Times reported that the British government had decided to "dot the coasts of the British Isles with a series of towers, each armed with two quick-firing guns of special design," while "a complete circle of towers" was to be built around "naval installations" and "at other especially vulnerable points". By December 1914
10043-421: The oil coolers have separate air intakes. Two were later converted to aerial refueling tanker prototypes, and redesignated YKB-29J . The remainder were used for reconnaissance , and designated RB-29J . The EB-29 (E stands for exempt), was used as a carrier aircraft in which the bomb bay was modified to accept and launch experimental aircraft. They were converted in the years following World War II . One EB-29
10164-482: The project was abandoned. The U.S. Navy acquired four B-29-BWs from the U.S. Army Air Forces on March 14, 1947. These aircraft were modified for long-range patrol missions and given the designation P2B-1S with Navy Bureau Numbers (BuNo) 84028, 84029, 84030 and 84031. BuNo 84029, previously AAF Ser. No. 45-21787, was modified to carry the Navy's Douglas D-558-2 Skyrocket high-speed research aircraft. The bomb bay
10285-411: The prototyping platform, or replace it with only the microcontroller chip and the circuitry that is relevant to their product. Prototype software is often referred to as alpha grade , meaning it is the first version to run. Often only a few functions are implemented, the primary focus of the alpha is to have a functional base code on to which features may be added. Once alpha grade software has most of
10406-438: The real EMD GP38-2 locomotive—which is the prototype of Athearn 's (among other manufacturers) locomotive model. Technically, any non-living object can serve as a prototype for a model, including structures, equipment, and appliances, and so on, but generally prototypes have come to mean full-size real-world vehicles including automobiles (the prototype 1957 Chevy has spawned many models), military equipment (such as M4 Shermans,
10527-406: The remote-controlled defensive systems were tested on a number of them, particularly the fourth one delivered. After alternative arrangements had been fully tested, defensive armament was standardised at ten .50-calibre machine guns in turret-mounted pairs. The YB-29 also featured a better fire control system . The B-29 was the original production version of the Superfortress. Since the new bomber
10648-463: The required features integrated into it, it becomes beta software for testing of the entire software and to adjust the program to respond correctly during situations unforeseen during development. Often the end users may not be able to provide a complete set of application objectives, detailed input, processing, or output requirements in the initial stage. After the user evaluation, another prototype will be built based on feedback from users, and again
10769-459: The result being a circuit that is electrically identical to the design but not physically identical to the final product. Open-source tools like Fritzing exist to document electronic prototypes (especially the breadboard-based ones) and move toward physical production. Prototyping platforms such as Arduino also simplify the task of programming and interacting with a microcontroller . The developer can choose to deploy their invention as-is using
10890-493: The sense of a mark left by a blow, then by a stamp struck by a die (note "typewriter"); by implication a scar or mark; by analogy a shape i.e. a statue, (figuratively) style, or resemblance; a model for imitation or illustrative example—note "typical"). Prototypes explore different aspects of an intended design: In general, the creation of prototypes will differ from creation of the final product in some fundamental ways: Engineers and prototype specialists attempt to minimize
11011-461: The shells' predicted trajectory. This was called deflection gun-laying, where "off-set" angles for range and elevation were set on the gunsight and updated as their target moved. In this method, when the sights were on the target, the barrel was pointed at the target's future position. Range and height of the target determined fuse length. The difficulties increased as aircraft performance improved. The British dealt with range measurement first, when it
11132-643: The single artillery branch has been responsible for both home and overseas ground-based air defence, although there was divided responsibility with the Royal Navy for air defence of the British Isles in World War I . However, during the Second World War , the RAF Regiment was formed to protect airfields everywhere, and this included light air defences. In the later decades of the Cold War this included
11253-477: The speed and direction of both the target and the projectile. Throughout the 20th century, air defence was one of the fastest-evolving areas of military technology, responding to the evolution of aircraft and exploiting technology such as radar, guided missiles and computing (initially electromechanical analogue computing from the 1930s on, as with equipment described below). Improvements were made to sensors, technical fire control, weapons, and command and control. At
11374-422: The start of the 20th century these were either very primitive or non-existent. Initially sensors were optical and acoustic devices developed during World War I and continued into the 1930s, but were quickly superseded by radar, which in turn was supplemented by optoelectronics in the 1980s. Command and control remained primitive until the late 1930s, when Britain created an integrated system for ADGB that linked
11495-463: The target and having its height. Second, that the target would maintain a steady course, speed and height. This HAA was to engage targets up to 24,000 ft (7.3 km). Mechanical time fuses were required because the speed of powder burning varied with height, so fuse length was not a simple function of time of flight. Automated fire ensured a constant rate of fire that made it easier to predict where each shell should be individually aimed. In 1925
11616-463: The two jet fighters) and their crews were lost in a crash on April 24, 1953. Early B-29/B-29As that were modified for photo reconnaissance carried the F-13/F-13A designations, with "F" meaning 'photo'. The aircraft (118 modified B-29BWs and B-29As) carried three K-17B, two K-22 and one K-18 cameras. Between the end of World War II (1945) and 1948 the designation was changed to FB-29J . In 1948,
11737-513: The use of the derivation ' prototypical '. This is a useful term in identifying objects, behaviours and concepts which are considered the accepted norm and is analogous with terms such as stereotypes and archetypes . The word prototype derives from the Greek πρωτότυπον prototypon , "primitive form", neutral of πρωτότυπος prototypos , "original, primitive", from πρῶτος protos , "first" and τύπος typos , "impression" (originally in
11858-409: The war and accumulated large amounts of data that was subjected to extensive analysis. As a result, they published the two-volume Textbook of Anti-Aircraft Gunnery in 1924–1925. It included five key recommendations for HAA equipment: Two assumptions underpinned the British approach to HAA fire; first, aimed fire was the primary method and this was enabled by predicting gun data from visually tracking
11979-437: The war ended, it was clear that the increasing capabilities of aircraft would require better means of acquiring targets and aiming at them. Nevertheless, a pattern had been set: anti-aircraft warfare would employ heavy weapons to attack high-altitude targets and lighter weapons for use when aircraft came to lower altitudes. World War I demonstrated that aircraft could be an important part of the battlefield, but in some nations it
12100-440: The years immediately after World War I, the prospect of another major war seemed remote, particularly in Europe, where the most militarily capable nations were, and little financing was available. Four years of war had seen the creation of a new and technically demanding branch of military activity. Air defence had made huge advances, albeit from a very low starting point. However, it was new and often lacked influential 'friends' in
12221-552: Was a version of the B-29 adapted for air-sea rescue duty after World War II . Sixteen B-29s were modified to carry a droppable A-3 lifeboat under the fuselage; redesignated SB-29, they were used mainly as rescue support for air units that flew long distances over water. The first SB-29s were received by the Air Rescue Service in February 1947. With the exception of the forward lower gun turret, all defensive armament
12342-493: Was an improved version of the original B-29 design, featuring 28-cylinder Pratt & Whitney R-4360 -35 Wasp Major engines of 3500 hp (2600 kW) each — nearly 60% more powerful than the usual Duplex-Cyclone . It also had a taller vertical stabilizer and a strengthened wing. The XB-44 was the testbed designation for the D model. When World War II ended, the B-29D was given the quartet of Wasp Major engines to become
12463-534: Was an improved version of the original B-29 production model. This is the definitive wartime variant of the B-29. All 1,119 B-29A's were built at the Boeing plant in Renton, Washington , formerly used by the United States Navy . Enhancements made in the B-29A included a better wing design and defensive modifications. Due to a demonstrated weakness to head-on fighter attacks, the number of machine guns in
12584-628: Was assigned the NACA number 137. As of May 2013, this aircraft was in the collection of Kermit Weeks at his Fantasy of Flight aviation museum in Polk City, Florida . The forward fuselage section was restored and briefly displayed at the Florida Air Museum in Lakeland, Florida . It has since been relocated to Fantasy of Flight's "Golden Hill" storage facility along with the remainder of
12705-586: Was capable of providing data suitable for controlling AA guns, and the British Radar, Gun Laying, Mark I , was designed to be used on AA gun positions and was in use by 1939. The Treaty of Versailles prevented Germany having AA weapons, and for example, the Krupps designers joined Bofors in Sweden. Some World War I guns were retained and some covert AA training started in the late 1920s. Germany introduced
12826-410: Was conducted on the XB-29 until February 18, 1943, when the second prototype crashed. The flight was conducted by Boeing 's chief test pilot, Edmund T. "Eddie" Allen on a two-hour powerplant performance test. The accident happened when leaking fuel from a filler cap in the wing leading edge ran down inside the leading-edge and ignited. The fire spread to the engines, and due to the much reduced power,
12947-516: Was converted to carry the famous Bell X-1 until it was replaced by a B-50 . Another was used to carry and test the XF-85 'parasite fighter' . This fighter was intended to be carried by the Convair B-36 on long-range missions to protect it from Soviet fighters. Another EB-29 was used to carry two EF-84B Thunderjet fighters as part of Project Tom-Tom . All three Tom-Tom aircraft (the B-29 and
13068-581: Was determined by time of flight, but the burning rate of the gunpowder was affected by altitude. The British pom-poms had only contact-fused ammunition. Zeppelins , being hydrogen-filled balloons, were targets for incendiary shells and the British introduced these with airburst fuses, both shrapnel type-forward projection of incendiary "pot" and base ejection of an incendiary stream. The British also fitted tracers to their shells for use at night. Smoke shells were also available for some AA guns, these bursts were used as targets during training. German air attacks on
13189-404: Was electrical; the operator entered the target range and had displays at guns; it was used with their 75 mm. The British Wilson-Dalby gun director used a pair of trackers and mechanical tachymetry; the operator entered the fuse length, and deflection angles were read from the instruments. By the start of World War I , the 77 mm had become the standard German weapon, and came mounted on
13310-538: Was modified to carry the Skyrocket II under the belly and drop for supersonic speed testing. The first Skyrocket test flight occurred on September 8, 1950, with test pilot William B. Bridgeman, and George Jansen flying the B-29. Scott Crossfield later broke Mach 2 flying the Skyrocket on November 20, 1953; the last Skyrocket flight was in December 1956. The P2B-1S "mother-ship" was nicknamed Fertile Myrtle and
13431-582: Was probably first used by the UK when Air Defence of Great Britain (ADGB) was created as a Royal Air Force command in 1925. However, arrangements in the UK were also called "anti-aircraft", abbreviated as AA , a term that remained in general use into the 1950s. After the First World War it was sometimes prefixed by "light" or "heavy" (LAA or HAA) to classify a type of gun or unit. Nicknames for anti-aircraft guns include "AA", "AAA" or "triple-A" (abbreviations of "anti-aircraft artillery"), "flak" (from
13552-476: Was realised that range was the key to producing a better fuse setting. This led to the height/range finder (HRF), the first model being the Barr & Stroud UB2, a two-metre optical coincident rangefinder mounted on a tripod. It measured the distance to the target and the elevation angle, which together gave the height of the aircraft. These were complex instruments and various other methods were also used. The HRF
13673-580: Was replaced by the nine-foot optical base UB 7 and the eighteen-foot optical base UB 10 (only used on static AA sites). Goertz in Germany and Levallois in France produced five m (16 ft) instruments. However, in most countries the main effort in HAA guns until the mid-1930s was improving existing ones, although various new designs were on drawing boards. From the early 1930s eight countries developed radar ; these developments were sufficiently advanced by
13794-558: Was retained; the aircraft additionally carried a variety of radio equipment, provisions, survival kits , and extra crew . The SB-29 was used operationally throughout the Korean War into the mid-1950s. It received its nickname from Dumbo , the Disney character, whose name was given to the aircraft used in previous missions to pick airmen up when they crashed at sea. The TB-29 was a trainer conversion of B-29 used to train crew for bombing missions; some were also used to tow targets, and
13915-544: Was slightly heavier and slower than the B-29. The Tu-4 presented a significant leap forward in Soviet strategic bombing. Not only did the Soviet Air Forces have the means to deliver nuclear weapons, but the Tu-4 had sufficient range to reach the United States on a one-way trip. On October 18, 1951, a Tu-4 was used in the first air-drop test of a Soviet atomic bomb . The Tu-4 had been phased out of Soviet service by
14036-554: Was soon joined by the height/fuse indicator (HFI), this was marked with elevation angles and height lines overlaid with fuse length curves, using the height reported by the HRF operator, the necessary fuse length could be read off. However, the problem of deflection settings — "aim-off" — required knowing the rate of change in the target's position. Both France and the UK introduced tachymetric devices to track targets and produce vertical and horizontal deflection angles. The French Brocq system
14157-501: Was the guns protecting spotting balloons, in which case the altitude could be accurately measured from the length of the cable holding the balloon. The first issue was ammunition. Before the war it was recognised that ammunition needed to explode in the air. Both high explosive (HE) and shrapnel were used, mostly the former. Airburst fuses were either igniferious (based on a burning fuse) or mechanical (clockwork). Igniferious fuses were not well suited for anti-aircraft use. The fuse length
14278-496: Was the prospect of strategic air attack that was the main issue, presenting both a threat and an opportunity. The experience of four years of air attacks on London by Zeppelins and Gotha G.V bombers had particularly influenced the British and was one of if not the main driver for forming an independent air force. As the capabilities of aircraft and their engines improved it was clear that their role in future war would be even more critical as their range and weapon load grew. However, in
14399-558: Was then quickly phased out when the B-47 Stratojet became operational. Washington B Mk 1 – This was the service name given to 88 B-29As supplied to the Royal Air Force . The B-29B was a modification used for low-level raids, designed with the intent of firebombing Japan . Since fighter opposition was minimal over Japan in late 1944, many of the Army Air Force leadership — most notably Curtis LeMay , commander of
14520-606: Was urgently needed, the production design was developed in tandem with the service testing. In fact, the first B-29 was completed only two months after the delivery of the first YB-29. Forty-six B-29s of this variant, built by the Glenn L. Martin Company at its Omaha plant, were used as the aircraft for the atomic bomb missions, modified to Silverplate specifications. Some 2,513 B-29s were manufactured by Boeing-Wichita (1,620), Bell-Atlanta (357), and Martin-Omaha (536). The B-29A
14641-787: Was used in the development of jet engines . Stripped of armament, a converted B-29B-55-BA (44-84043)(Bell) designated the XB-29G carried experimental jet engines in its bomb bay, which were extended into the airstream for testing during flight. This plane was used to test the Allison J35 , General Electric J47 and J73 jet engines. The XB-29H to test armament configurations was a converted B-29A. Experimentation in piston engines continued. Six B-29s (redesignated YB-29J ) of various designation were upgraded to R-3350-79 engines. Other engine-associated items were also upgraded, including new Curtiss propellers , and 'Andy Gump' cowlings, in which
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