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JT4A
The Pratt & Whitney J75 (civilian designation: JT4A) is an axial-flow turbojet engine first flown in 1955. A two-spool design in the 17,000 lbf (76 kN) thrust class, the J75 was essentially the bigger brother of the Pratt & Whitney J57 (JT3C). It was known in civilian service as the JT4A, and in a variety of stationary roles as the GG4 and FT4. Design and development In military use, the J75 was used on the Convair F-106 Delta Dart, Lockheed U-2, and Republic F-105 Thunderchief. It was also utilized in the prototype and experimental Avro Canada CF-105 Arrow, Lockheed A-12, Martin P6M SeaMaster, North American YF-107, and Vought XF8U-3 Crusader III. Before the arrival of the Pratt & Whitney JT3D turbofan engine, the JT4A was used to power certain Boeing 707 and Douglas DC-8 models, bringing improved field performance in the medium-range Boeing 707-220 and Douglas DC-8-20, and intercontinental range in the Boeing 707-320 and the Douglas DC-8-30. By late 1959, P&W had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boeing 707
The Boeing 707 is an American, long-range, narrow-body airliner, the first jetliner developed and produced by Boeing Commercial Airplanes. Developed from the Boeing 367-80 prototype first flown in 1954, the initial first flew on December 20, 1957. Pan American World Airways began regular 707 service on October 26, 1958. With versions produced until 1979, the 707 was a swept wing, quadjet with podded engines. Its larger fuselage cross-section allowed six-abreast economy seating, retained in the later 720, 727, 737, and 757 models. Although it was not the first commercial jetliner in service, the 707 was the first to be widespread and is often credited with beginning the Jet Age. It dominated passenger air transport in the 1960s, and remained common through the 1970s, on domestic, transcontinental, and transatlantic flights, as well as cargo and military applications. It established Boeing as a dominant airliner manufacturer with its 7x7 series. The initial, was powered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douglas DC-8
The Douglas DC-8 (sometimes McDonnell Douglas DC-8) is a long-range narrow-body airliner built by the American Douglas Aircraft Company. After losing the May 1954 US Air Force tanker competition to the Boeing KC-135, Douglas announced in July 1955 its derived jetliner project. In October 1955, Pan Am made the first order along with the competing Boeing 707, and many other airlines followed. The first DC-8 was rolled out in Long Beach Airport on April 9, 1958, and flew for the first time on May 30. FAA certification was achieved in August 1959 and the DC-8 entered service with Delta Air Lines on September 18. The six-abreast, low wing airliner was a four-engined jet aircraft with initial variants being long. The DC-8-10 was powered by Pratt & Whitney JT3C turbojets and had a MTOW, the DC-8-20 had more powerful JT4A turbojets for a MTOW. The intercontinental models had more fuel capacity and up to MTOW, powered by JT4As for the Series 30 and by Rolls-Royce Conway turbof ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pratt & Whitney J57
The Pratt & Whitney J57 (company designation: JT3C) is an axial-flow turbojet engine developed by Pratt & Whitney in the early 1950s. The J57 (first run January 1950) was the first 10,000 lbf (45 kN) thrust class engine in the United States. The J57/JT3C was developed into the J52 turbojet, the J75/JT4A turbojet, the JT3D/TF33 turbofan, and the XT57 turboprop (of which only one was built). The J57 and JT3C saw extensive use on fighter jets, jetliners, and bombers for many decades. Design and development The J57 was a development of the Pratt & Whitney XT45 (PT4) turboprop engine that was originally intended for the Boeing XB-52. As the B-52 power requirements grew, the design evolved into a turbojet, the JT3. Pratt & Whitney designed the J57 to have a relatively high overall pressure ratio to help improve both Thrust-specific fuel consumption and specific thrust, but it was known that throttling a single high pressure ratio compressor would cause stability problems. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pratt & Whitney JT3D
The Pratt & Whitney JT3D is an early turbofan aircraft engine derived from the Pratt & Whitney J57, Pratt & Whitney JT3C. It was first run in 1958 and was first flown in 1959 under a B-45 Tornado test aircraft. Over 8,000 JT3Ds were produced between 1959 and 1985. Most JT3D engines still in service today are used on military aircraft, where the engine is referred to by its US military designation of TF33. Design and development Aware of the competition from the Rolls-Royce Conway turbofan, Pratt & Whitney decided to develop the JT3D turbofan from the JT3C turbojet for later deliveries of the Boeing 707 and the Douglas DC-8, then nearing entry into service. A 2-stage fan replaced the first 3 stages of the 9-stage JT3C LP compressor. On the LP turbine, the second stage was enlarged and a third stage added. Unlike GE with the CJ805-23, Pratt & Whitney had not undertaken any transonic fan research prior to designing the JT3D, so they were unable to incorporate a single stage unit in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lockheed U-2
The Lockheed U-2, nicknamed "''Dragon Lady''", is an American single-jet engine, high altitude reconnaissance aircraft operated by the United States Air Force (USAF) and previously flown by the Central Intelligence Agency (CIA). It provides day and night, high-altitude (), all-weather intelligence gathering. Lockheed Corporation originally proposed it in 1953, it was approved in 1954, and its first test flight was in 1955. It was flown during the Cold War over the Soviet Union, China, Vietnam War, Vietnam, and Cuba. In 1960, Francis Gary Powers, Gary Powers was 1960 U-2 incident, shot down in a CIA U-2C over the Soviet Union by a surface-to-air missile (SAM). Major Rudolf Anderson, Rudolf Anderson Jr. was shot down in a U-2 during the Cuban Missile Crisis in 1962. U-2s have taken part in post-Cold War conflicts in War in Afghanistan (2001–2021), Afghanistan and Operation Iraqi Freedom, Iraq, and supported several multinational NATO operations. The U-2 has also been used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peak Demand
Peak demand on an electrical grid is simply the highest electrical power demand that has occurred over a specified time period (Gönen 2008). Peak demand is typically characterized as annual, daily or seasonal and has the unit of power. Peak demand, peak load or on-peak are terms used in energy demand management describing a period in which electrical power is expected to be provided for a sustained period at a significantly higher than average supply level. Peak demand fluctuations may occur on daily, monthly, seasonal and yearly cycles. For an electric utility company, the actual point of peak demand is a single half-hour or hourly period which represents the highest point of customer consumption of electricity. At this time there is a combination of office, domestic demand and at some times of the year, the fall of darkness. Some utilities will charge customers based on their individual peak demand. The highest demand during each month or even a single 15 to 30 minute period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight International
''Flight International'' is a monthly magazine focused on aerospace. Published in the United Kingdom and founded in 1909 as "A Journal devoted to the Interests, Practice, and Progress of Aerial Locomotion and Transport", it is the world's oldest continuously published aviation news magazine. ''Flight International'' is published by DVV Media Group. Competitors include Jane's Information Group and ''Aviation Week''. Former editors of, and contributors include H. F. King, Bill Gunston, John W. R. Taylor and David Learmount. History The founder and first editor of ''Flight'' was Stanley Spooner. He was also the creator and editor of ''The Automotor Journal'', originally titled ''The Automotor Journal and Horseless Vehicle''.Guide To British Industrial History: Biographies: ''Stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USCGC Polar Sea (WAGB-11)
USCGC ''Polar Sea'' (WAGB-11) is a United States Coast Guard heavy icebreaker. Commissioned on 23 February 1977, the ship was built by Lockheed Shipbuilding and Construction Company of Seattle along with her sister ship, ''Polar Star'' (WAGB-10). Her home port is Seattle, Washington. ''Polar Sea'' has been out of service due to failure of five of her six Alco main diesel engines. Machinery ''Polar Sea'' has a computerized propulsion control system to effectively manage six diesel-powered propulsion generators, three diesel-powered ship's service generators, three propulsion gas turbines, and other equipment vital to the operation of the ship. Its three shafts are each turned by either one gas turbine or two diesel-electric power plants. Each shaft is connected to a 16-foot (4.9-m) diameter, four-bladed, controllable-pitch propeller. For all three shafts, the diesel-electric plants can produce a total of 18,000 shaft horsepower (13,425 kilowatts) and the gas turbine plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USCGC Polar Star (WAGB-10)
USCGC ''Polar Star'' (WAGB-10) is a United States Coast Guard heavy icebreaker. Commissioned in 1976, the ship was built by Lockheed Shipbuilding and Construction Company of Seattle, Washington along with sister ship, . Homeported in Seattle, ''Polar Star'' operates under the control of Coast Guard Pacific Area and coordinates her operations through the Ice Operations Section of the United States Coast Guard. After ''Polar Sea'' was deactivated in 2010, ''Polar Star'' became the US's only heavy icebreaker. The Coast Guard's only other icebreaker, , despite being classified as a "medium icebreaker", is actually larger than 'Polar Star' (13,623 LT versus 16,000 LT). Replacement ships for what is called the Polar Security Cutter program have been ordered for a new generation of USCG icebreakers. Design In August 1971 the Secretary of Transportation announced awarding of a contract to Lockheed Shipbuilding and Construction Company of Seattle, Washington, "to build the world's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CODOG
Combined diesel or gas (CODOG) is a type of propulsion system for ships that need a maximum speed that is considerably faster than their cruise speed, particularly warships like modern frigates or corvettes. For every propeller shaft there is one diesel engine for cruising speed and one geared gas turbine for high speed dashes. Both are connected to the shaft with clutches; only one system is driving the ship, in contrast to CODAG systems that can use the combined power output of both. The advantage of CODOG is a simpler gearing compared to CODAG, but it needs either more powerful or additional gas turbines to achieve the same maximum power output. The disadvantage of CODOG is that the fuel consumption at high speed is poor compared to CODAG. CODOG vessels * MGB 2009, a modified Motor Gun Boat of the Royal Navy (1947), and *The two German torpedo boats ''Pfeil'' and ''Strahl'' (''Vosper'' class, 1963-65) *The US Navy s (built 1966-1971) *The US Coast Guard s (from 1967) *s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WikiProject Aircraft
A WikiProject, or Wikiproject, is a Wikimedia movement affinity group for contributors with shared goals. WikiProjects are prevalent within the largest wiki, Wikipedia, and exist to varying degrees within sister projects such as Wiktionary, Wikiquote, Wikidata, and Wikisource. They also exist in different languages, and translation of articles is a form of their collaboration. During the COVID-19 pandemic, CBS News noted the role of Wikipedia's WikiProject Medicine in maintaining the accuracy of articles related to the disease. Another WikiProject that has drawn attention is WikiProject Women Scientists, which was profiled by '' Smithsonian'' for its efforts to improve coverage of women scientists which the profile noted had "helped increase the number of female scientists on Wikipedia from around 1,600 to over 5,000". On Wikipedia Some Wikipedia WikiProjects are substantial enough to engage in cooperative activities with outside organizations relevant to the field at issue. For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Natural gas is colorless and odorless, so odorizers such as mercaptan (which smells like sulfur or rotten eggs) are commonly added to natural gas supplies for safety so that leaks can be readily detected. Natural gas is a fossil fuel and non-renewable resource that is formed when layers of organic matter (primarily marine microorganisms) decompose under anaerobic conditions and are subjected to intense heat and pressure underground over millions of years. The energy that the decayed organisms originally obtained from the sun via photosynthesis is stored as chemical energy within the molecules of methane and other hydrocarbons. Natural gas can be burned fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
