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54-525: The Northrop YF-17 (nicknamed "Cobra" ) was a prototype lightweight fighter aircraft designed by Northrop aviation for the United States Air Force 's Lightweight Fighter (LWF) technology evaluation program. The LWF was initiated because many in the fighter community believed that aircraft like the F-15 Eagle were too large and expensive for many combat roles. The YF-17 was the culmination of

108-633: 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

162-499: 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 . Nomex Nomex

216-425: 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

270-401: A conventional construction. Like the wings, the leading and trailing edges were constructed of composite facesheets over honeycomb core. A composite speedbrake was located on top of the fuselage between the engines. The aircraft was powered by two 14,400-pound-force (64 kN) General Electric YJ101-GE-100 afterburning turbojets, installed next to each other to minimize thrust asymmetry in

324-526: 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

378-872: A long line of Northrop designs, beginning with the N-102 Fang in 1956, continuing through the F-5 family. Although it lost the LWF competition to the F-16 Fighting Falcon , the YF-17 was selected for the new Naval Fighter Attack Experimental ( VFAX ) program. In enlarged form, the F/A-18 Hornet was adopted by the United States Navy and United States Marine Corps to replace the A-7 Corsair II and F-4 Phantom II , complementing

432-483: A purely land-based fighter. The aircraft's main design elements date to early 1965, from the internal Northrop project N-300. The N-300 was derived from the F-5E , and features a longer fuselage, small leading-edge root extensions (LERX), and more powerful GE15-J1A1 turbojets , rated at 9,000  lbf (40 kN). The wing position was raised slightly to increase ground clearance for ordnance. The N-300 further evolved into

486-501: A rigid and lightweight plate is produced, which can improve the efficiency of the soundboard. While the 'laminated' technique was created by Matthias Dammann, the use of Nomex within was first employed by luthier Gernot Wagner. The deaths in fiery crashes of race car drivers Fireball Roberts at Charlotte, and Eddie Sachs and Dave MacDonald at Indianapolis in 1964, led to the use of flame-resistant fabrics such as Nomex. In early 1966 Competition Press and Autoweek reported: "During

540-463: A simple ranging-radar. The cockpit had an ejection seat inclined at 18°, a bubble canopy , and a head-up display (HUD). The thin wings carried no fuel, and in areas such as the leading and trailing edge and the LERX, were composed of a Nomex honeycomb core with composite facesheets. The rear of the aircraft had twin all-moving stabilators of aluminum over a honeycomb core, and twin vertical stabilizers of

594-579: A single vertical stabilizer was insufficient at high angles of attack, and it was changed to twin vertical stabilizers , canted at 45°, resulting in a "relaxed longitudinal stability" design, which enhances maneuverability. Northrop was not yet confident in fly-by-wire controls and retained mechanically actuated flight controls. The resulting aircraft, unveiled on 28 January 1971, had a maximum weight of 40,000 lb (18,144 kg) and maximum speed of Mach  2, but stirred little interest among foreign buyers. The first prototype ( serial number 72-1569 )

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648-499: 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

702-634: A trapezoidal shape formed by a sweep of 20° at the quarter-chord line, and an unswept trailing edge , but was over double the area, with 400 sq ft (37 m) as opposed to 186 sq ft (17.3 m) of the F-5E. Initially shoulder mounted, the wings were lowered to the mid position. Its most distinctive new feature were the LERXs that tapered into the fuselage under the cockpit. They added about 50% additional lift at angles of attack exceeding 50°, improving maneuvering. The extensions also aligned airflow into

756-551: A typical example of something such as in 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

810-468: 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

864-605: Is a common piece of racing and firefighting equipment. It is placed on the head on top of a firefighter 's face mask. The hood protects the portions of the head not covered by the helmet and face mask from the intense heat of the fire. Wildland firefighters wear Nomex shirts and trousers as part of their personal protective equipment during wildfire suppression activities. Racing car drivers wear driving suits constructed of Nomex and or other fire retardant materials , along with Nomex gloves, long underwear, balaclavas , socks, helmet lining and shoes, to protect them in

918-518: 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

972-481: Is a trademarked term for an inherently flame-resistant fabric with meta - aramid chemistry widely used for industrial applications and fire protection equipment. It was developed in the early 1960s by DuPont and first marketed in 1967. The fabric is often combined with Kevlar to increase its resistance for breakage or tear. Nomex and related aramid polymers are related to nylon , but have aromatic backbones, and hence are more rigid and more durable. Nomex

1026-422: Is an example of a meta variant of the aramids ( Kevlar is a para aramid). Unlike Kevlar, Nomex strands cannot align during filament polymerization and have less strength: its ultimate tensile strength is 340 MPa (49,000 psi). However, it has excellent thermal, chemical, and radiation resistance for a polymer material. It can withstand temperatures of up to 370 °C (700 °F). Nomex

1080-513: 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

1134-478: Is produced by condensation reaction from the monomers m -phenylenediamine and isophthaloyl chloride . It is sold in both fiber and sheet forms and is used as a fabric where resistance from heat and flame is required. Nomex sheet is actually a calendered paper and made in a similar fashion. Nomex Type 410 paper was the first Nomex paper developed and one of the higher volume grades made, mostly for electrical insulation purposes. Wilfred Sweeny (1926–2011),

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1188-414: 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

1242-490: 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

1296-409: 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

1350-574: 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

1404-515: 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

1458-524: 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

1512-478: The Stiletto 27 . Nomex is used in industrial applications as a filter in exhaust filtration systems, typically a baghouse , that deal with hot gas emissions found in asphalt plants, cement plants, steel smelting facilities, and non-ferrous metal production facilities. Nomex is used in some classical guitar tops in order to create a 'composite' soundboard. When Nomex is laminated between 2 spruce or cedar 'skins',

1566-421: 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

1620-635: The DuPont scientist responsible for discoveries leading to Nomex, earned a DuPont Lavoisier Medal in 2002 partly for this work. Nomex Paper is used in electrical laminates such as circuit boards and transformer cores as well as fireproof honeycomb structures where it is saturated with a phenolic resin . Honeycomb structures such as these, as well as mylar -Nomex laminates, are used extensively in aircraft construction. Firefighting, military aviation, and vehicle racing industries use Nomex to create clothing and equipment that can withstand intense heat. A Nomex hood

1674-632: The LWF program. In August 1974, Congress directed the Navy to make maximum use of the technology and hardware of the LWF for its new lightweight strike fighter, the VFAX . As neither contractor had experience with naval fighters, they sought partners to provide that expertise. General Dynamics teamed with Vought for the Vought Model 1600 ; Northrop with McDonnell Douglas for the F-18. Each submitted revised designs in line with

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1728-499: The Navy needs for a long-range radar and multirole capabilities. Prototype YF-17 72-1569 was sent to NASA's Dryden Research Center for base drag studies from 27 May to 14 July 1976 prior to the first F/A-18 prototype under development. Data from Northrop YF-17: The fighter they didn't want General characteristics Performance Armament Related development Aircraft of comparable role, configuration, and era Prototype A prototype can also mean

1782-502: The P-530 Cobra, which uses 13,000 lbf (58 kN) GE15-J1A5 engines, with a very small 0.25:1 bypass ratio leading to the nickname "leaky turbojet". The bypass air was required for cooling the afterburner and nozzle and the cool bypass duct surface allowed the engine bay to be constructed of lighter, cheaper materials. The P-530 wing planform and nose section were similar to the F-5, with

1836-624: The U.S. space program, Nomex has been used for the Thermal Micrometeoroid Garment on the Extravehicular Mobility Unit (in conjunction with Kevlar and Gore-Tex ) and ACES pressure suit, both for fire and extreme environment (water immersion to near vacuum) protection, and as thermal blankets on the payload bay doors, fuselage, and upper wing surfaces of the Space Shuttle Orbiter. It has also been used for

1890-478: The YF-17 competed against the General Dynamics YF-16 . The two YF-17 prototypes flew 288 test flights, totaling 345.5 hours. The YF-17 attained a top speed of Mach 1.95, a peak load factor of 9.4 g , and a maximum altitude of over 50,000 ft (15,000 m). It demonstrated a maximum angle of attack of 68 degrees at 28 kn IAS. Initially, the U.S. Navy was not heavily involved as a participant in

1944-871: The airbags for the Mars Pathfinder and Mars Exploration Rover missions , the Galileo atmospheric probe , the Cassini-Huygens Titan probe, as an external covering on the AERCam Sprint , and is planned to be incorporated into NASA's upcoming Crew Exploration Vehicle . Nomex has been used as an acoustic material in Troy, NY, at Rensselaer Polytechnic Institute's Experimental Media and Performing Arts Center ( EMPAC ) main concert hall. A ceiling canopy of Nomex reflects high and mid frequency sound, providing reverberation, while letting lower frequency sound partially pass through

1998-509: The cannon moved from the underside of the fuselage, to the upper part. Design of the YF-17 and the prototype YJ101 engine, a development of the GE15 engine, consumed over a million man-hours, and 5,000 hours of wind tunnel testing. The YF-17 was primarily constructed of aluminum , in conventional semi- monocoque stressed-skin construction, though over 900 lb (408 kg) of its structure comprised graphite/epoxy composite. The small nose contained

2052-537: The canopy. According to RPI President Shirley Ann Jackson, EMPAC is the first venue in the world to use Nomex as an architectural material for acoustic reasons. Nomex (like Kevlar) is also used in the production of loudspeaker drivers. Honeycomb-structured Nomex paper is used as a spacer between layers of lead in the ATLAS Liquid Argon Calorimeter, and as a laminate core for hull and deck construction in custom boats such as Stiletto Catamarans like

2106-407: 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

2160-572: The engines at high angles of attack. The resemblance to the head of a cobra led to the adoption of the nickname "Cobra" for the P-530. When the Lightweight Fighter program was announced in 1971, Northrop modified the P-530 into the P-600 design that would be designated YF-17A. Whereas the P-530 was intended as a multi-role aircraft, the P-600 was to be strictly an air-to-air demonstrator, and consequently

2214-417: The event of a fire . Military pilots and aircrew wear flight suits made of over 92 percent Nomex to protect them from cockpit fires. It is also worn as sailors' anti-flash gear . Troops riding in ground vehicles often wear Nomex for fire protection. Kevlar thread is often used to hold the fabric together at seams. Military tank drivers also typically use Nomex hoods as protection against fire. In

Northrop YF-17 - Misplaced Pages Continue

2268-419: The event of an engine failure. To minimise engine removal time they were removed from below the aircraft without disturbing the empennage controls. Each engine drove an hydraulic pump for independent aircraft systems. Unlike the P-530, the YF-17 had partial fly-by-wire, called an electronic control augmentation system (ECAS), which used ailerons, rudders, and stabilators for primary flight control. Studies showed

2322-480: 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

2376-528: 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

2430-464: 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

2484-508: 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

2538-475: 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

2592-685: The more expensive F-14 Tomcat . This design, conceived as a small and lightweight fighter, was scaled up to the Boeing F/A-18E/F Super Hornet , which is similar in size and weight to the F-15 and ultimately replaced the F-14. A non-naval, export variant developed and marketed by Northrop, the F-18L failed to attract buyers; nevertheless, many air forces have operated the McDonnell Douglas F/A-18 as

2646-411: 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

2700-438: 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,

2754-463: 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

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2808-459: 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

2862-493: 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

2916-491: Was rolled out at Hawthorne on 4 April 1974; its first flight at Edwards AFB came on 9 June with Henry "Hank" Chouteau at the controls flying for 61 minutes reaching an altitude of 18,000 feet and a maximum speed of 610 miles per hour. Chouteau afterwards remarked that, "When our designers said that in the YF-17 they were going to give the airplane back to the pilot, they meant it. It's a fighter pilot's fighter." The second YF-17 (s/n 72-1570 ) first flew on 21 August. Through 1974,

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