Misplaced Pages

#959040

22-561: In 1949 the US government canceled the Boeing XB-55 contract, which had been an effort to produce a subsonic replacement for the just-being-introduced Boeing B-47 Stratojet . The XB-55 project had started in 1947, but by the end of the decade it was apparent that if strategic penetration in warfare were to be successful at all, it would require aircraft much faster than the jet fighter aircraft which were then being placed into operation. Thus,

44-443: A prototype if it provides at least part of the functionality of a system and enables testing of a design. Mock-ups are used by designers mainly to acquire feedback from users. Mock-ups address the idea captured in a popular engineering one-liner: "You can fix it now on the drafting board with an eraser or you can fix it later on the construction site with a sledge hammer". Mockups are used as design tools virtually everywhere

66-811: A strategic bomber . The XB-55 was intended to be a replacement for the Boeing B-47 Stratojet in United States Air Force (USAF) service. The XB-55 concept was contained in a Request for Proposal (RFP) issued by the United States Air Force in October 1947, two months before the first flight of the XB-47 prototype. Several United States manufacturers responded to the RFP. Boeing was selected from among this group and given

88-472: A contract on 1 July 1948 to conduct further engineering studies. Boeing's initial approach was to mount four turboprop engines on an airframe similar to its B-47: the wing would have less sweepback; the Allison T40 -A-2 engines would drive three-blade contra-rotating propellers , i.e. , six blades per engine; the engines were to be mounted in nacelles hung from the wings, two per side; the landing gear

110-533: A new product is designed. Mockups are used in the automotive device industry as part of the product development process, where dimensions, overall impression, and shapes are tested in a wind tunnel experiment. They can also be used to test consumer reaction. Mockups are part of the military acquisition process. Mockups are often used to test human factors and aerodynamics , for example. In this context, mockups include wire-frame models . They can also be used for public display and demonstration purposes prior to

132-458: A prototype. Data from Air Force Museum Fact Sheet General characteristics Performance Armament Related development Aircraft of comparable role, configuration, and era Related lists Mockup In manufacturing and design , a mockup , or mock-up , is a scale or full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes. A mockup may be

154-404: A single function, and derive results from the tests to enhance the products power and usability on the whole. Mockups, wireframes and prototypes are not so cleanly distinguished in software and systems engineering , where mockups are a way of designing user interfaces on paper or in computer images. A software mockup will thus look like the real thing, but will not do useful work beyond what

176-784: Is then "faked" using mock objects. This is especially important if the functions that are simulated like this are difficult to obtain (for example because it involves complex computation) or if the result is non-deterministic, such as the readout of a sensor. A common style of software design is Service-oriented architecture (SOA), where many components communicate via protocols such as HTTP . Service virtualization and API mocks and simulators are examples of implementations of mockups or so called over-the-wire test doubles in software systems that are modelling dependent components or microservices in SOA environments. Mockup software can also be used for micro level evaluation, for example to check

198-705: The XB-55 program were government funding constraints and the growing realization that the B-47 was becoming more successful than first projected. On 29 January 1949, the Air Materiel Command was directed to cancel the Boeing XB-55 contract. Under a revised contract, the Boeing Project 474 was converted into the Boeing Project 479, which included a study of using six J40 turbojet engines in place of

220-527: The XB-59 was to have a crew of three, and would be powered by four GE J73-X24A turbojet engines, mounted in the roots of the 73-foot span wings. The landing gear would be similar to the bicycle arrangement found on the B-47 and B-52 Stratofortress , with wingtip-mounted outriggers. The Boeing contract for the XB-59 was canceled in late 1952 after the Convair company's submission, designated B-58 Hustler ,

242-508: The development of a prototype, as with the case of the Lockheed Martin F-35 Lightning II mock-up aircraft. Mockups are used in the consumer goods industry as part of the product development process, where dimensions, human factors, overall impression, and commercial art are tested in marketing research . Mockups help to visualise how all design decisions play together, they are convincing and closely resemble

SECTION 10

#1732790524960

264-519: The engine manufacturer and the propeller manufacturer over whether the Allison T40-A-2 driveshaft was strong enough to take the forces caused at high revolutions per minute of the propellers. Allison was predicting that it would be at least four years before a successful powerplant would be delivered. In October 1948, a conference in Dayton, Ohio was addressing the problems of the XB-55 when it

286-440: The final product, it can be easily revised rather than much later in the production stage, It also helps in visualisation of package design projects in 3D & speed up approvals. Mockups are commonly required by designers, architects, and end users for custom furniture and cabinetry. The intention is often to produce a full-sized replica, using inexpensive materials in order to verify a design. Mockups are often used to determine

308-449: The funding made available by the XB-55 cancellation was earmarked for the study of a supersonic medium bomber, and a request for proposals was extended to several aircraft companies. Boeing submitted a proposal for a four-engine, high-wing aircraft with a highly streamlined fuselage . The four engines would be buried in thickened wing roots; the remaining wing planform was highly tapered. Developed under weapons system designation MX-1965,

330-408: The initial drawings and sketches. Mockups used for this purpose can be on a reduced scale. The cost of making mockups is often more than repaid by the savings made by avoiding going into production with a design which needs improvement. The most common use of mockups in software development is to create user interfaces that show the end user what the software will look like without having to build

352-596: The proportions of the piece, relating to various dimensions of the piece itself, or to fit the piece into a specific space or room. The ability to see how the design of the piece relates to the rest of the space is also an important factor in determining size and design. When designing a functional piece of furniture, such as a desk or table, mockups can be used to test whether they suit typical human shapes and sizes. Designs that fail to consider these issues may not be practical to use. Mockups can also be used to test color, finish, and design details which cannot be visualized from

374-497: The software or the underlying functionality. Software UI mockups can range from very simple hand drawn screen layouts, through realistic bitmaps, to semi functional user interfaces developed in a software development tool. Mockups are often used to create unit tests - there they are usually called mock objects . The main reason to create such mockups is to be able to test one part of a software system (a unit) without having to use dependent modules. The function of these dependencies

396-491: The turboprops on a similar wing platform, but with a thicker root section. Work on detailed engineering and mockup construction was canceled, although Boeing was contracted to continue conceptual studies and wind tunnel investigations. These studies proved valuable in development of the Boeing B-52 Stratofortress , which first flew on April 15, 1952. The XB-55 project did not result in construction of

418-456: The user sees. A software prototype, on the other hand, will look and work just like the real thing. In many cases it is best to design or prototype the user interface before source code is written or hardware is built, to avoid having to go back and make expensive changes. Early layouts of a World Wide Web site or pages are often called mockups . A large selection of proprietary or open-source software tools are available for this purpose. At

440-471: Was proposed over lunch that the XB-52 (Boeing Model 464), which until that point had been planned with turboprop engines, could be equipped with the forthcoming Pratt & Whitney J57 turbojet engines. Within a week, it was clear that not only would the XB-52 outperform the XB-55, it could be flying at least a year before the XB-55 could be expected to have reliable engines. Also bearing on the decision to abandon

462-425: Was selected for development. The Boeing effort was a design study only, and no construction was involved. Data from "US Bombers," Lloyd S. Jones, 1974 General characteristics Performance Armament Aircraft of comparable role, configuration, and era Related lists Boeing XB-55 The Boeing XB-55 (company designation Model 474 ) was a proposed Boeing aircraft designed to be

SECTION 20

#1732790524960

484-410: Was to be similar to the B-47's tandem gear with outriggers retracting into the outboard engine nacelles. The XB-55 had a projected top speed of 490 mph (790 km/h) and a cruising speed of 435 mph (700 km/h), with a maximum weight of 153,000 lb (69,000 kg), a wingspan of 135 ft (41 m), and length of 118.9 ft (36.2 m). There was a major disagreement between

#959040