An aircraft engine is a component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are always either lightweight piston engines or gas turbines, except for small multicopter UAVs which are always electric aircraft. In commercial aviation, the major players in the manufacturing of turbofan engines are Pratt & Whitney, General Electric, Rolls-Royce, CFM International. A major entrant into the market launched in 2016 when Aeroengine Corporation of China was formed by organizing smaller companies engaged in designing and manufacturing aircraft engines into a new state owned behemoth of 96,000 employees. In general aviation, the dominant manufacturer of turboprop engines has been Whitney. General Electric announced in 2015 entrance into the market. 1848: John Stringfellow made a steam engine for a 10-foot wingspan model aircraft which achieved the first powered flight, albeit with negligible payload. 1903: Charlie Taylor built an inline aeroengine for the Wright Flyer.
1903: Manly-Balzer engine sets standards for radial engines. 1906: Léon Levavasseur produces a successful water-cooled V8 engine for aircraft use. 1908: René Lorin patents a design for the ramjet engine. 1908: Louis Seguin designed the Gnome Omega, the world's first rotary engine to be produced in quantity. In 1909 a Gnome powered Farman III aircraft won the prize for the greatest non-stop distance flown at the Reims Grande Semaine d'Aviation setting a world record for endurance of 180 kilometres. 1910: Coandă-1910, an unsuccessful ducted fan aircraft exhibited at Paris Aero Salon, powered by a piston engine. The aircraft never flew, but a patent was filed for routing exhaust gases into the duct to augment thrust. 1914: Auguste Rateau suggests using exhaust-powered compressor – a turbocharger – to improve high-altitude performance. VI heavy bomber becomes the earliest known supercharger-equipped aircraft to fly, with a Mercedes D. II straight-six engine in the central fuselage driving a Brown-Boveri mechanical supercharger for the R.30/16's four Mercedes D.
IVa engines. 1918: Sanford Alexander Moss picks up Rateau's idea and creates the first successful turbocharger 1926: Armstrong Siddeley Jaguar IV, the first series-produced supercharged engine for aircraft use. 1930: Frank Whittle submitted his first patent for a turbojet engine. June 1939: Heinkel He 176 is the first successful aircraft to fly powered by a liquid-fueled rocket engine. August 1939: Heinkel HeS 3 turbojet propels the pioneering German Heinkel He 178 aircraft. 1940: Jendrassik Cs-1, the world's first run of a turboprop engine. It is not put into service. 1943 Daimler-Benz DB 670, first turbofan runs 1944: Messerschmitt Me 163B Komet, the world's first rocket-propelled combat aircraft deployed. 1945: First turboprop-powered aircraft flies, a modified Gloster Meteor with two Rolls-Royce Trent engines. 1947: Bell X-1 rocket-propelled aircraft exceeds the speed of sound. 1948: 100 shp 782, the first turboshaft engine to be applied to aircraft use. 1949: Leduc 010, the world's first ramjet-powered aircraft flight.
1950: Rolls-Royce Conway, the world's first production turbofan, enters service. 1968: General Electric TF39 high bypass turbofan enters service delivering greater thrust and much better efficiency. 2002: HyShot scramjet flew in dive. 2004: NASA X-43, the first scramjet to maintain altitude. In this entry, for clarity, the term "inline engine" refers only to engines with a single row of cylinders, as used in automotive language, but in aviation terms, the phrase "inline engine" covers V-type and opposed engines, is not limited to engines with a single row of cylinders; this is to differentiate them from radial engines. A straight engine has an number of cylinders, but there are instances of three- and five-cylinder engines; the greatest advantage of an inline engine is that it allows the aircraft to be designed with a low frontal area to minimize drag. If the engine crankshaft is located above the cylinders, it is called an inverted inline engine: this allows the propeller to be mounted high up to increase ground clearance, enabling shorter landing gear.
The disadvantages of an inline engine include a poor power-to-weight ratio, because the crankcase and crankshaft are long and thus heavy. An in-line engine may be either air-cooled or liquid-cooled, but liquid-cooling is more common because it is difficult to get enough air-flow to cool the rear cylinders directly. Inline engines were common in early aircraft. However, the inherent disadvantages of the design soon became apparent, the inline design was abandoned, becoming a rarity in modern aviation. For other configurations of aviation inline engine, such as U-engines, H-engines, etc.. See Inline engine. Cylinders in this engine are arranged in two in-line banks tilted 60–90 degrees apart from each other and driving a common crankshaft; the vast majority of V engines are water-cooled. The V design provides a higher power-to-weight ratio than an inline engine, while still providing a small frontal area; the most famous example of this design is the legendary Rolls-Royce Merlin engine, a 27-litre 60° V12 engine used in, among others, the Spitfires that played a major role in the Battle of Britain.
A horizontally opposed engine called a flat or boxer engine, ha
The hectare is an SI accepted metric system unit of area equal to a square with 100-metre sides, or 10,000 m2, is used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about 0.405 hectare and one hectare contains about 2.47 acres. In 1795, when the metric system was introduced, the "are" was defined as 100 square metres and the hectare was thus 100 "ares" or 1⁄100 km2; when the metric system was further rationalised in 1960, resulting in the International System of Units, the are was not included as a recognised unit. The hectare, remains as a non-SI unit accepted for use with the SI units, mentioned in Section 4.1 of the SI Brochure as a unit whose use is "expected to continue indefinitely". The name was coined from the Latin ārea; the metric system of measurement was first given a legal basis in 1795 by the French Revolutionary government. The law of 18 Germinal, Year III defined five units of measure: The metre for length The are for area The stère for volume of stacked firewood The litre for volumes of liquid The gram for massIn 1960, when the metric system was updated as the International System of Units, the are did not receive international recognition.
The International Committee for Weights and Measures makes no mention of the are in the current definition of the SI, but classifies the hectare as a "Non-SI unit accepted for use with the International System of Units". In 1972, the European Economic Community passed directive 71/354/EEC, which catalogued the units of measure that might be used within the Community; the units that were catalogued replicated the recommendations of the CGPM, supplemented by a few other units including the are whose use was limited to the measurement of land. The names centiare, deciare and hectare are derived by adding the standard metric prefixes to the original base unit of area, the are; the centiare is one square metre. The deciare is ten square metres; the are is a unit of area, used for measuring land area. It was defined by older forms of the metric system, but is now outside the modern International System of Units, it is still used in colloquial speech to measure real estate, in particular in Indonesia, in various European countries.
In Russian and other languages of the former Soviet Union, the are is called sotka. It is used to describe the size of suburban dacha or allotment garden plots or small city parks where the hectare would be too large; the decare is derived from deca and are, is equal to 10 ares or 1000 square metres. It is used in Norway and in the former Ottoman areas of the Middle East and the Balkans as a measure of land area. Instead of the name "decare", the names of traditional land measures are used, redefined as one decare: Stremma in Greece Dunam, donum, or dönüm in Israel, Jordan, Lebanon and Turkey Mål is sometimes used for decare in Norway, from the old measure of about the same area; the hectare, although not a unit of SI, is the only named unit of area, accepted for use within the SI. In practice the hectare is derived from the SI, being equivalent to a square hectometre, it is used throughout the world for the measurement of large areas of land, it is the legal unit of measure in domains concerned with land ownership and management, including law, agriculture and town planning throughout the European Union.
The United Kingdom, United States, to some extent Canada use the acre instead. Some countries that underwent a general conversion from traditional measurements to metric measurements required a resurvey when units of measure in legal descriptions relating to land were converted to metric units. Others, such as South Africa, published conversion factors which were to be used "when preparing consolidation diagrams by compilation". In many countries, metrication clarified existing measures in terms of metric units; the following legacy units of area have been redefined as being equal to one hectare: Jerib in Iran Djerib in Turkey Gong Qing in Hong Kong / mainland China Manzana in Argentina Bunder in The Netherlands The most used units are in bold. One hectare is equivalent to: 1 square hectometre 15 mǔ or 0.15 qǐng 10 dunam or dönüm 10 stremmata 6.25 rai ≈ 1.008 chō ≈ 2.381 feddan Conversion of units Hecto- Hectometre Order of magnitude Official SI website: Table 6. Non-SI units accepted for use with the International System of Units
Antelope Valley is located in northern Los Angeles County and the southeast portion of Kern County and constitutes the western tip of the Mojave Desert. It is situated between the San Gabriel Mountains; the valley was named for the pronghorns that roamed there until they were all but eliminated in the 1880s by hunting, or resettled in other areas. The principal cities in the Antelope Valley are Lancaster; the Antelope Valley comprises the western tip of the Mojave Desert, opening up to the Victor Valley and the Great Basin to the east. Lying north of the San Gabriel Mountains and southeast of the Tehachapis, this desert ecosystem spans 2,200 square miles. Precipitation in the surrounding mountain ranges contributes to groundwater recharge; the Antelope Valley is home to a wide range of animals. This includes hundreds of plants such as the California Juniper, Joshua tree, California Scrub Oak and wildflowers, notably the California poppy. Winter brings much-needed rain which penetrates the area's dry ground, bringing up native grasses and wildflowers.
Poppy season depends on the precipitation, but a good bloom can be killed off by the unusual weather in the late winter and early spring months. The Antelope Valley gets its name from its history of pronghorn grazing in large numbers. In 1882-85, the valley lost 30,000 head of antelope half of the species for which it was named. Unusually heavy snows in both the mountains and the valley floor drove the antelope toward their normal feeding grounds in the eastern part of the valley. Since they would not cross the railroad tracks, many of them starved to death; the remainder of these pronghorn were hunted for their fur by settlers. Once abundant, they migrated into the Central Valley. A drought in the early 1900s caused a scarcity in their main food source. Now the sighting of a pronghorn is rare, although there are still a small number in the western portion of the valley. Human water use in the Antelope Valley depends on pumping of groundwater from the valley's aquifers and on importing additional water from the California Aqueduct.
Long-term groundwater pumping has lowered the water table, thereby increasing pumping lifts, reducing well efficiency, causing land subsidence. While aqueducts supply additional water that meets increasing human demand for agricultural and domestic uses, diversion of water from the Sacramento-San Joaquin River Delta in northern California has caused and causes adverse environmental and social effects in the delta: "Over decades, competing uses for water supply and habitat have jeopardized the Delta’s ability to meet either need. All stakeholders agree the estuary is in trouble and requires long-term solutions to ensure reliable, quality water supplies and a healthy ecosystem." The Antelope Valley's population growth and development place considerable stress on the local and regional water systems. According to David Leighton of the United States Geological Survey: "A deliberate management effort will be required to meet future water demand in the Antelope Valley without incurring significant economic and environmental costs associated with overuse of the ground-water resource."
The first peoples of the Antelope Valley include the Kawaiisu, Kitanemuk and Tataviam. Europeans first entered during the colonization of North America. Father Francisco Garces, a Spanish Franciscan friar, is believed to have traveled the west end of the valley in 1776; the Spanish established El Camino Viejo through the western part of the valley between Los Angeles and the missions of the San Francisco Bay in the 1780s. By 1808, the Spanish had moved the native people out into missions. Jedediah Smith came through in 1827, John C. Fremont made a scientific observation of the valley in 1844. After Fremont's visit the 49ers crossed the valley via the Old Tejon Pass into the San Joaquin Valley on their way to the gold fields. A better wagon road, the Stockton – Los Angeles Road route to Tejon Pass, followed in 1854. Stagecoach lines across the southern foothills came through the valley along this wagon road, were the preferred method for travelers before the coming of the Southern Pacific Railroad in 1876.
The rail service linking the valley to the Central Valley and Los Angeles started its first large influx of white settlers, farms and towns soon sprouted on the valley floor. The aircraft industry took hold in the valley at Plant 42 in 1952. Edwards AFB called Muroc Army Air Field, was established in 1933. In recent decades the valley has become a bedroom community to the Greater Los Angeles area. Major housing tract development and population growth took off beginning in 1983, which has increased the population of Palmdale around 12 times its former size as of 2006. Neighboring Lancaster has increased its population since the early 1980s to around three times its former level. Major retail has followed the population influx, centered on Palmdale's Antelope Valley Mall; the Antelope Valley is home to over 475,000 people. Non-Hispanic whites make up 48% of the population of the Antelope Valley and form a majority or plurality in most of its cities and towns. Hispanics are the next largest group, followed by Asian Americans.
Some long-term residents living far out in the desert have been cited by Los Angeles County's nuisance abatement teams for code violations, forcing residents to either make improvements or move. One of the properties is a church building, used as a filming location for Kill Bill; the code enforcers have arrived on some of their visits in SWAT team formats. Edwards Air Force Base lie
Greater Los Angeles
Greater Los Angeles is the second-largest urban region in the United States, encompassing five counties in southern California, extending from Ventura County in the west to San Bernardino County and Riverside County on the east, with Los Angeles County in the center and Orange County to the southeast. It consists of three metropolitan areas in Southern California. Throughout the 20th century, it was one of the fastest-growing regions in the United States, although growth has slowed since 2000; as of the 2010 U. S. Census, the Los Angeles Metropolitan Statistical Area had a population of nearly 13 million residents. Meanwhile, the larger metropolitan region's population at the 2010 census was estimated to be over 17.8 million residents, a 2015 estimate reported a population of about 18.7 million. Either definition makes it the second largest metropolitan region in the country, behind the New York metropolitan area, as well as one of the largest urban agglomerations in the world; the agglomeration of the urbanized Greater Los Angeles area surrounds the urban core of Los Angeles County.
The regional term is defined to refer to the more-or-less continuously urbanized area stretching from Ventura County to the southern border of Orange County and from the Pacific Ocean to the Coachella Valley in the Inland Empire. The US Census Bureau defines the Los Angeles-Long Beach, CA Combined Statistical Area as including the entire Los Angeles County, Ventura County, Orange County and the two counties of the Inland Empire. However, this Census definition includes large, sparsely populated and desert swaths of Los Angeles, San Bernardino and Riverside counties that are not part of the urbanized region; the term "Greater Los Angeles" does not include San Diego County, whose urbanized area is separated from San Clemente, the southernmost contiguous urbanized area south of Los Angeles, by a 16.4-mile stretch of the Marine Corps Base Camp Pendleton. According to the U. S. Census Bureau, the Los Angeles metropolitan area has a total area of 4,850 square miles, while the wider combined statistical area covers 33,954 square miles, making it the largest metropolitan region in the United States by land area.
However, more than half of this area lies in the sparsely populated eastern areas of Riverside and San Bernardino counties. In addition to being the nexus of the world's largest entertainment industry, Greater Los Angeles is a global center of business, international trade, media, tourism and technology, transportation. Los Angeles has a long-standing reputation for sprawl; the area is in fact sprawling, but according to the 2000 census, the "Los Angeles-Long Beach-Anaheim" Urbanized Area had a population density of 7,068 inhabitants per square mile, covering 1,668 square miles of land area, making it the most densely populated Urbanized Area in the United States. For comparison, the "New York–Newark" Urbanized Area as a whole had a population density of 5,309 per square mile, covering 3,353 square miles of land area. Los Angeles' sprawl may originate in the region's decentralized structure, its major commercial and cultural institutions are geographically dispersed rather than being concentrated in a single downtown or central area.
The population density of Los Angeles proper is low when compared to some other large American cities such as New York, San Francisco and Chicago. Densities are high within a 5-mile radius of downtown, where some neighborhoods exceed 20,000 people per square mile. What gives the entire Los Angeles metro region a high density is the fact that many of the city's suburbs and satellites cities have high density rates. Within its urbanized areas, Los Angeles is noted for having small lot sizes and low-rise buildings. Buildings in the area are low when compared to other large cities due to zoning regulations. Los Angeles became a major city just as the Pacific Electric Railway spread population to smaller cities much as interurbans did in East Coast cities. In the first decades of the twentieth century, the area was marked by a network of dense but separate cities linked by rail; the ascendance of the automobile helped fill in the gaps between these commuter towns with lower-density settlements. Starting in the early twentieth century, there was a large growth in population on the western edges of the city moving to the San Fernando Valley and out into the Conejo Valley in eastern Ventura County.
Many working class whites migrated to this area during the 1960s and 1970s out of East and Central Los Angeles. As a result, there was a large growth in population into the Conejo Valley and into Ventura County through the US 101 corridor. Making the US 101 a full freeway in the 1960s and expansions that followed helped make commuting to Los Angeles easier and opened the way for development westward. Development in Ventura County and along the US 101 corridor remains controversial, with open-space advocates battling those who feel business development is necessary to economic growth. Although the area still has abundant amount of open space and land all of it was put aside and mandated never to be developed as part of the master plan of each city; because of this, the area, once a inexpensive area to buy real estate, saw rising real estate prices well into the 2000s. Median home prices in the Conejo Valley for instance, ranged from $700,000 to
Mesa Airlines, Inc. is an American regional airline based in Phoenix, Arizona. It is an FAA Part 121-certificated air carrier operating under air carrier certificate number MASA036A issued on June 29, 1979, it is a subsidiary of Mesa Air Group and operates flights as American Eagle and United Express via respective code sharing agreements with American Airlines and United Airlines. It serves more than 180 markets in the Western Hemisphere. In a 1997 article from the Journal of Air Transportation, Mesa's safety record was noted as having the fewest incidents among domestic regional airlines At that time. Mesa filed for Chapter 11 bankruptcy in January 2010, hoping to shed financial obligations for leases on airplanes it no longer needed, emerged from bankruptcy in March of 2011. Since 2013, Mesa has added more aircraft to its fleet than any other regional airline. In November 2017, Mesa opened a new training center in Phoenix; the 23,000-square-foot facility features a full-size CRJ-200 cabin trainer aircraft, 14 classrooms, has the capacity to train 300 crew members at one time.
Mesa Airlines operates as: the regional marketing brand of American Airlines. Mesa began flying routes as American Eagle in 2014 from American's hubs in Dallas/Fort Worth and Phoenix using Bombardier CRJ900 regional jet aircraft. United Express, a mainline airline marketing sub-brand using United Express liveried fleet of Bombardier CRJ700 and Embraer 175 aircraft under a revenue-guarantee code sharing agreement, its hubs are at Washington Dulles for the CRJ700 aircraft. Air Midwest CalPac Desert Sun Airlines FloridaGulf Airlines Go! Liberty Express Airlines Mountain West Airlines Skyway Airlines Superior Airlines Mesa began operations as Mesa Air Shuttle in Farmington, New Mexico, in 1980. From 1989 through 1998, Mesa Airlines operated as a conglomeration of up to eight separate airlines. For the history of the acquisition and expansion of Mesa Airlines during this time see Mesa Air Group; the following history section details the history of the individual airlines that comprised Mesa Airlines during this time frame.
The original Mesa Air Shuttle was a flight division of JB Aviation in Farmington, New Mexico and operated a single route from Farmington to Albuquerque using a Piper Saratoga aircraft. In 1981 as the original Frontier Airlines was discontinuing its flights between the two cities, Mesa obtained a twin engine Piper Navajo Chieftain and increased service on the route. In 1982 the original owners sold the company to Janie Risley; the Risley's expanded the carrier by acquiring a fleet of 14-passenger seat Beechcraft 99 commuter turboprops and adding service throughout New Mexico and surrounding states with a hub at Albuquerque. In 1985 larger 19-passenger seat Beechcraft 1900's were acquired which replaced the Beech 99's and became the backbone of Mesa's fleet. By 1987 up to 47 daily departures were operating from Albuquerque to 18 cities. In 1987 a Denver hub was created when Mesa acquired Centennial Airlines which operated several routes from Denver into Wyoming. After an initial route from Farmington and Gallup to Phoenix began in 1985, Phoenix was expanded into a hub in 1989 with new routes throughout Arizona.
In 1990, most Denver flights were incorporated into the United Express division which Mesa had acquired from Aspen Airways. In 1992, when Mesa established a code share with America West Airlines, its Phoenix hub was turned over to the America West Express division. A minor hub was operated at Farmington in the late 1980s with up to 22 daily flights connecting Albuquerque and Salt Lake City to Durango and Telluride, CO. For a brief time in 1995 and 1996, the Mesa Airlines operation at Albuquerque, the United Express operation in Denver, the America West Express operation in Phoenix were all known as operated by Mountain West Airlines. In 1997 and 1998, routes from Little Rock to Nashville and Wichita and from Nashville to Tupelo were added, first as Mesa Airlines later as US Airways Express. In 1997, Mesa established a small hub at Fort Worth Meacham International Airport, using two Bombardier CRJ200 regional jet aircraft, providing service from Fort Worth to San Antonio and Houston Hobby, as well as new routes from Colorado Springs to Nashville and San Antonio.
The venture was short-lived and these routes were all eliminated during corporate restructuring. The Albuquerque hub was merged into Air Midwest in 2001 but operated as a code share for Mesa Airlines until the hub was dissolved at the end of 2007. In 1998, Mesa moved its headquarters from Farmington, NM to Phoenix, AZ. In September 1992, Mesa negotiated a code sharing agreement with America West Airlines to operate as America West Express out of its Phoenix hub, serving 12 cities; these routes were from the independent Mesa operation and several Beech 1900D aircraft were painted in the America West Airlines scheme. The code share allowed increased frequency and increased load factors and expansion into several new markets. In 1995, Mesa created a new subdivision called Desert Sun Airlines and acquired a pair of Fokker 70 jets for use on new America West Express routes from Phoenix to Des Moines and Spokane. Desert Sun was merged into the Mesa Airlines division in 1997 and its Fokker 70 aircraft were replaced by Canadair CRJ-200 regional jet aircraft.
The CRJ-200 aircraft began replacing the Beechcraft 1900D and Embraer EMB-120 Brasilia turboprops. The BE-1900Ds were transitioned over to Mesa's Air Midwest subsidiary. Beginning in December 1997, Mesa began operating de Havilland Canada DHC-8 Dash 8 series 200 aircraft between Ph
The Douglas DC-3 is a fixed-wing propeller-driven airliner that revolutionized air transport in the 1930s and 1940s. Its lasting effect on the airline industry and World War II makes it one of the most significant transport aircraft produced, it has a cruise speed of 207 mph, capacity of 21 to 32 passengers or 6,000 lbs of cargo and a range of 1,500 mi. The DC-3 is a twin-engine metal monoplane with a tailwheel-type landing gear and was developed as a larger, improved 14-bed sleeper version of the Douglas DC-2, it had many exceptional qualities compared to previous aircraft. It had good range and could operate from short runways, it carried passengers in greater comfort. Before the war it pioneered many air travel routes, it made worldwide flights possible. It is considered the first airliner. Civil DC-3 production ended in 1942 at 607 aircraft. Military versions, including the C-47 Skytrain, Russian- and Japanese-built versions, brought total production to over 16,000. Following the war, the airliner market was flooded with surplus C-47s and other ex-military transport aircraft, Douglas' attempts to produce an upgraded DC-3 failed due to cost.
Post-war, the DC-3 was made obsolete on main routes by more advanced types such as the Douglas DC-6 and Lockheed Constellation, but the design proved exceptionally adaptable and useful. Large numbers continue to see service in a wide variety of niche roles well into the 21st century. In 2013 it was estimated that 2,000 DC-3s and military derivatives were still flying, a testament to the durability of the design. "DC" stands for "Douglas Commercial". The DC-3 was the culmination of a development effort that began after an inquiry from Transcontinental and Western Airlines to Donald Douglas. TWA's rival in transcontinental air service, United Airlines, was starting service with the Boeing 247 and Boeing refused to sell any 247s to other airlines until United's order for 60 aircraft had been filled. TWA asked Douglas to build an aircraft that would allow TWA to compete with United. Douglas' design, the 1933 DC-1, was promising, led to the DC-2 in 1934; the DC-2 was a success. The DC-3 resulted from a marathon telephone call from American Airlines CEO C. R. Smith to Donald Douglas, when Smith persuaded a reluctant Douglas to design a sleeper aircraft based on the DC-2 to replace American's Curtiss Condor II biplanes.
Douglas agreed to go ahead with development only after Smith informed him of American's intention to purchase twenty aircraft. The new aircraft was engineered by a team led by chief engineer Arthur E. Raymond over the next two years, the prototype DST first flew on December 17, 1935, its cabin was 92 in wide, a version with 21 seats instead of the 14–16 sleeping berths of the DST was given the designation DC-3. There was no prototype DC-3; the DC-3 and DST popularized air travel in the United States. Eastbound transcontinental flights could cross the U. S. in about 15 hours with three refueling stops. A few years earlier such a trip entailed short hops in slower and shorter-range aircraft during the day, coupled with train travel overnight. A variety of radial engines were available for the DC-3. Early-production civilian aircraft used Wright R-1820 Cyclone 9s, but aircraft used the Pratt & Whitney R-1830 Twin Wasp, which gave better high-altitude and single-engine performance. Five DC-3S Super DC-3s with Pratt & Whitney R-2000 Twin Wasps were built in the late 1940s, three of which entered airline service.
Total production of all variants was 16,079. More than 400 remained in commercial service in 1998. Production was as follows: 607 civil variants of the DC-3. Production of DSTs ended in mid-1941 and civil DC-3 production ended in early 1943, although dozens of DSTs and DC-3s ordered by airlines that were produced between 1941 and 1943 were impressed into the US military while still on the production line. Military versions were produced until the end of the war in 1945. A larger, more powerful Super DC-3 was launched in 1949 to positive reviews; the civilian market, was flooded with second-hand C-47s, many of which were converted to passenger and cargo versions. Only five Super DC-3s were built, three of them were delivered for commercial use; the prototype Super DC-3 served the U. S. Navy with the designation YC-129 alongside 100 R4Ds, upgraded to the Super DC-3 specification. From the early 1950s, some DC-3s were modified to use Rolls-Royce Dart engines, as in the Conroy Turbo Three. Other conversions featured Armstrong Siddeley Pratt & Whitney PT6A turbines.
The Greenwich Aircraft Corp DC-3-TP is a conversion with an extended fuselage and with Pratt & Whitney Canada PT6A-65AR or PT6A-67R engines fitted. The Basler BT-67 is a conversion of the DC-3/C-47. Basler refurbishes C-47s and DC-3s at Oshkosh, fitting them with Pratt & Whitney Ca
A helicopter is a type of rotorcraft in which lift and thrust are supplied by rotors. This allows the helicopter to take off and land vertically, to hover, to fly forward and laterally; these attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of VTOL aircraft cannot perform. The English word helicopter is adapted from the French word hélicoptère, coined by Gustave Ponton d'Amécourt in 1861, which originates from the Greek helix "helix, whirl, convolution" and pteron "wing". English language nicknames for helicopter include "chopper", "copter", "helo", "heli", "whirlybird". Helicopters were developed and built during the first half-century of flight, with the Focke-Wulf Fw 61 being the first operational helicopter in 1936; some helicopters reached limited production, but it was not until 1942 that a helicopter designed by Igor Sikorsky reached full-scale production, with 131 aircraft built. Though most earlier designs used more than one main rotor, it is the single main rotor with anti-torque tail rotor configuration that has become the most common helicopter configuration.
Tandem rotor helicopters are in widespread use due to their greater payload capacity. Coaxial helicopters, tiltrotor aircraft, compound helicopters are all flying today. Quadcopter helicopters pioneered as early as 1907 in France, other types of multicopter have been developed for specialized applications such as unmanned drones; the earliest references for vertical flight came from China. Since around 400 BC, Chinese children have played with bamboo flying toys; this bamboo-copter is spun by rolling a stick attached to a rotor. The spinning creates lift, the toy flies when released; the 4th-century AD Daoist book Baopuzi by Ge Hong describes some of the ideas inherent to rotary wing aircraft. Designs similar to the Chinese helicopter toy appeared in some Renaissance paintings and other works. In the 18th and early 19th centuries Western scientists developed flying machines based on the Chinese toy, it was not until the early 1480s, when Italian polymath Leonardo da Vinci created a design for a machine that could be described as an "aerial screw", that any recorded advancement was made towards vertical flight.
His notes suggested that he built small flying models, but there were no indications for any provision to stop the rotor from making the craft rotate. As scientific knowledge increased and became more accepted, people continued to pursue the idea of vertical flight. In July 1754, Russian Mikhail Lomonosov had developed a small coaxial modeled after the Chinese top but powered by a wound-up spring device and demonstrated it to the Russian Academy of Sciences, it was powered by a spring, was suggested as a method to lift meteorological instruments. In 1783, Christian de Launoy, his mechanic, used a coaxial version of the Chinese top in a model consisting of contrarotating turkey flight feathers as rotor blades, in 1784, demonstrated it to the French Academy of Sciences. Sir George Cayley, influenced by a childhood fascination with the Chinese flying top, developed a model of feathers, similar to that of Launoy and Bienvenu, but powered by rubber bands. By the end of the century, he had progressed to using sheets of tin for rotor blades and springs for power.
His writings on his experiments and models would become influential on future aviation pioneers. Alphonse Pénaud would develop coaxial rotor model helicopter toys in 1870 powered by rubber bands. One of these toys, given as a gift by their father, would inspire the Wright brothers to pursue the dream of flight. In 1861, the word "helicopter" was coined by Gustave de Ponton d'Amécourt, a French inventor who demonstrated a small steam-powered model. While celebrated as an innovative use of a new metal, the model never lifted off the ground. D'Amecourt's linguistic contribution would survive to describe the vertical flight he had envisioned. Steam power was popular with other inventors as well. In 1878 the Italian Enrico Forlanini's unmanned vehicle powered by a steam engine, rose to a height of 12 meters, where it hovered for some 20 seconds after a vertical take-off. Emmanuel Dieuaide's steam-powered design featured counter-rotating rotors powered through a hose from a boiler on the ground. In 1887 Parisian inventor, Gustave built and flew a tethered electric model helicopter.
In July 1901, the maiden flight of Hermann Ganswindt's helicopter took place in Berlin-Schöneberg. A movie covering the event was taken by Max Skladanowsky. In 1885, Thomas Edison was given US$1,000 by James Gordon Bennett, Jr. to conduct experiments towards developing flight. Edison built a helicopter and used the paper for a stock ticker to create guncotton, with which he attempted to power an internal combustion engine; the helicopter was damaged by explosions and one of his workers was badly burned. Edison reported that it would take a motor with a ratio of three to four pounds per horsepower produced to be successful, based on his experiments. Ján Bahýľ, a Slovak inventor, adapted the internal combustion engine to power his helicopter model that reached a height of 0.5 meters in 1901. On 5 May 1905, his helicopter flew for over 1,500 meters. In 1908, Edison patented his own design for a helicopter powered by a gasoline engine with box kites attached to a mast by cables for a rotor, but it never flew.
In 1906, two French brothers and Louis Breguet, began experimenting with airfoils for helicopters. In