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145-512: The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James Allison in 1929 the company was purchased by the Fisher brothers . Fisher sold the company to General Motors , which owned it for most of its history. It was acquired by Rolls-Royce plc in 1995 to become the US subsidiary , Rolls-Royce North America . A predecessor of Allison Engine Company,

290-634: A deflationary spiral started in 1931. Farmers faced a worse outlook; declining crop prices and a Great Plains drought crippled their economic outlook. At its peak, the Great Depression saw nearly 10% of all Great Plains farms change hands despite federal assistance. At first, the decline in the U.S. economy was the factor that triggered economic downturns in most other countries due to a decline in trade, capital movement, and global business confidence. Then, internal weaknesses or strengths in each country made conditions worse or better. For example,

435-443: A gas turbine engine offered. Thus was born the idea to mate a turbine engine to a traditional propeller. Because gas turbines optimally spin at high speed, a turboprop features a gearbox to lower the speed of the shaft so that the propeller tips don't reach supersonic speeds. Often the turbines that drive the propeller are separate from the rest of the rotating components so that they can rotate at their own best speed (referred to as

580-418: A silver standard , almost avoided the depression entirely. The connection between leaving the gold standard as a strong predictor of that country's severity of its depression and the length of time of its recovery has been shown to be consistent for dozens of countries, including developing countries . This partly explains why the experience and length of the depression differed between regions and states around

725-599: A "family aircraft". Before work on this design had progressed very far, Fisher sold the company to General Motors, which ended development owing to financial pressures of the Great Depression . Nevertheless, Gilman pressed ahead with the cylinder design, building a "paper project" V-12 engine. The Army was once again uninterested, but instead suggested Allison try selling it to the United States Navy . The Navy agreed to fund development of A and B models to

870-541: A LiftFan nozzle was tested in 1997 at NASA's Lewis facility. By 1997, a complete prototype had been demonstrated by the Rolls-Royce owned but American-controlled Allison Advanced Development Company. In 1965 a drag racer, Jim Lytle, created a car known as Quad Al which incorporated four World War II surplus V-12 Allison aero-engines in a four-wheel drive configuration, and developing approximately 12,000 hp (8,900 kW). Although its engines started, it never ran;

1015-618: A better efficiency. A hybrid system as emergency back-up and for added power in take-off is offered for sale by Axter Aerospace, Madrid, Spain. Small multicopter UAVs are almost always powered by electric motors. Reaction engines generate the thrust to propel an aircraft by ejecting the exhaust gases at high velocity from the engine, the resultant reaction of forces driving the aircraft forwards. The most common reaction propulsion engines flown are turbojets, turbofans and rockets. Other types such as pulsejets , ramjets , scramjets and pulse detonation engines have also flown. In jet engines

1160-419: A combustion section where fuel is added and ignited, one or more turbines that extract power from the expanding exhaust gases to drive the compressor, and an exhaust nozzle that accelerates the exhaust gases out the back of the engine to create thrust. When turbojets were introduced, the top speed of fighter aircraft equipped with them was at least 100 miles per hour faster than competing piston-driven aircraft. In

1305-564: 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. Perhaps the most famous example of this design is the legendary Rolls-Royce Merlin engine, a 27-litre (1649 in ) 60° V12 engine used in, among others, the Spitfires that played a major role in the Battle of Britain . A horizontally opposed engine, also called

1450-490: A cooling system into the air duct of a hydrogen jet engine permits greater fuel injection at high speed and obviates the need for the duct to be made of refractory or actively cooled materials. This greatly improves the thrust/weight ratio of the engine at high speed. It is thought that this design of engine could permit sufficient performance for antipodal flight at Mach 5, or even permit a single stage to orbit vehicle to be practical. The hybrid air-breathing SABRE rocket engine

1595-440: A cylinder on the other side. Opposed, air-cooled four- and six-cylinder piston engines are by far the most common engines used in small general aviation aircraft requiring up to 400 horsepower (300 kW) per engine. Aircraft that require more than 400 horsepower (300 kW) per engine tend to be powered by turbine engines . An H configuration engine is essentially a pair of horizontally opposed engines placed together, with

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1740-414: A division of General Motors . The company's only regular production item was a patented steel-backed lead bearing, which was used in various high performance engines. It also built various drive shafts, extensions and gear chains for high power engines, on demand. Later its main business was the conversion of older Liberty engines to more powerful models, both for aircraft and marine use. Allison needed

1885-408: A flat or boxer engine, has two banks of cylinders on opposite sides of a centrally located crankcase. The engine is either air-cooled or liquid-cooled, but air-cooled versions predominate. Opposed engines are mounted with the crankshaft horizontal in airplanes , but may be mounted with the crankshaft vertical in helicopters . Due to the cylinder layout, reciprocating forces tend to cancel, resulting in

2030-604: A former privately run bank, bearing no relation to the U.S. government (not to be confused with the Federal Reserve ). Unable to pay out to all of its creditors, the bank failed. Among the 608 American banks that closed in November and December 1930, the Bank of United States accounted for a third of the total $ 550 million deposits lost and, with its closure, bank failures reached a critical mass. In an initial response to

2175-572: A fraction of the cost of traditional engines. Such conversions first took place in the early 1970s; and as of 10 December 2006 the National Transportation Safety Board has only seven reports of incidents involving aircraft with Mazda engines, and none of these is of a failure due to design or manufacturing flaws. The most common combustion cycle for aero engines is the four-stroke with spark ignition. Two-stroke spark ignition has also been used for small engines, while

2320-407: A free-turbine engine). A turboprop is very efficient when operated within the realm of cruise speeds it was designed for, which is typically 200 to 400 mph (320 to 640 km/h). Turboshaft engines are used primarily for helicopters and auxiliary power units . A turboshaft engine is similar to a turboprop in principle, but in a turboprop the propeller is supported by the engine and the engine

2465-467: A greater reduction in credit. On 5 April 1933, President Roosevelt signed Executive Order 6102 making the private ownership of gold certificates , coins and bullion illegal, reducing the pressure on Federal Reserve gold. British economist John Maynard Keynes argued in The General Theory of Employment, Interest and Money that lower aggregate expenditures in the economy contributed to

2610-456: A handful of types are still in production. The last airliner that used turbojets was the Concorde , whose Mach 2 airspeed permitted the engine to be highly efficient. A turbofan engine is much the same as a turbojet, but with an enlarged fan at the front that provides thrust in much the same way as a ducted propeller , resulting in improved fuel efficiency . Though the fan creates thrust like

2755-600: A modern industrial city handled shortages of money and resources. Often they updated strategies their mothers used when they were growing up in poor families. Cheap foods were used, such as soups, beans and noodles. They purchased the cheapest cuts of meat—sometimes even horse meat—and recycled the Sunday roast into sandwiches and soups. They sewed and patched clothing, traded with their neighbors for outgrown items, and made do with colder homes. New furniture and appliances were postponed until better days. Many women also worked outside

2900-402: A monetary contraction first-hand were forced to join the deflationary policy since higher interest rates in countries that performed a deflationary policy led to a gold outflow in countries with lower interest rates. Under the gold standard's price–specie flow mechanism , countries that lost gold but nevertheless wanted to maintain the gold standard had to permit their money supply to decrease and

3045-569: A peak pressure of 30 MPa (300 bar). Although engine weight increases by 30%, aircraft fuel consumption is reduced by 15%. Sponsored by the European Commission under Framework 7 project LEMCOTEC , Bauhaus Luftfahrt, MTU Aero Engines and GKN Aerospace presented the concept in 2015, raising the overall engine pressure ratio to over 100 for a 15.2% fuel burn reduction compared to 2025 engines. On multi-engine aircraft, engine positions are numbered from left to right from

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3190-478: A piston-engine with two 10 piston banks without a high-pressure turbine, increasing efficiency with non-stationary isochoric - isobaric combustion for higher peak pressures and temperatures. The 11,200 lb (49.7 kN) engine could power a 50-seat regional jet . Its cruise TSFC would be 11.5 g/kN/s (0.406 lb/lbf/hr) for an overall engine efficiency of 48.2%, for a burner temperature of 1,700 K (1,430 °C), an overall pressure ratio of 38 and

3335-521: A place where his race car engines could be modified and repaired. On January 1, 1917 Allison moved into a building at what was to become, in later years, the Indianapolis Motor Speedway . Along with the move, Allison hired Norman H. Gillman, a very talented engineer from a competing race team, as his chief engineer. Allison moved to Florida to invest in real estate after World War I, leaving Gillman in charge. Allison did not want

3480-424: A propeller, the surrounding duct frees it from many of the restrictions that limit propeller performance. This operation is a more efficient way to provide thrust than simply using the jet nozzle alone, and turbofans are more efficient than propellers in the transsonic range of aircraft speeds and can operate in the supersonic realm. A turbofan typically has extra turbine stages to turn the fan. Turbofans were among

3625-425: A search for replacement fuels for general aviation aircraft a priority for pilots’ organizations. Turbine engines and aircraft diesel engines burn various grades of jet fuel . Jet fuel is a relatively less volatile petroleum derivative based on kerosene , but certified to strict aviation standards, with additional additives. Model aircraft typically use nitro engines (also known as "glow engines" due to

3770-567: A serious issue in the 1930s. Support for increasing welfare programs during the depression included a focus on women in the family. The Conseil Supérieur de la Natalité campaigned for provisions enacted in the Code de la Famille (1939) that increased state assistance to families with children and required employers to protect the jobs of fathers, even if they were immigrants. In rural and small-town areas, women expanded their operation of vegetable gardens to include as much food production as possible. In

3915-463: A single row of cylinders, as used in automotive language, but in aviation terms, the phrase "inline engine" also covers V-type and opposed engines (as described below), and is not limited to engines with a single row of cylinders. This is typically to differentiate them from radial engines . A straight engine typically has an even number of cylinders, but there are instances of three- and five-cylinder engines. The greatest advantage of an inline engine

4060-480: A small cadre of Labour, but the vast majority of Labour leaders denounced MacDonald as a traitor for leading the new government. Britain went off the gold standard , and suffered relatively less than other major countries in the Great Depression. In the 1931 British election, the Labour Party was virtually destroyed, leaving MacDonald as prime minister for a largely Conservative coalition. In most countries of

4205-404: A smooth running engine. Opposed-type engines have high power-to-weight ratios because they have a comparatively small, lightweight crankcase. In addition, the compact cylinder arrangement reduces the engine's frontal area and allows a streamlined installation that minimizes aerodynamic drag. These engines always have an even number of cylinders, since a cylinder on one side of the crankcase "opposes"

4350-713: A standstill agreement froze Germany's foreign liabilities for six months. Germany received emergency funding from private banks in New York as well as the Bank of International Settlements and the Bank of England. The funding only slowed the process. Industrial failures began in Germany, a major bank closed in July and a two-day holiday for all German banks was declared. Business failures were more frequent in July, and spread to Romania and Hungary. The crisis continued to get worse in Germany, bringing political upheaval that finally led to

4495-647: A very limited degree for its airships , until the crash of the USS Macon in 1935, when the Navy's need for a 1,000 hp (750 kW) engine disappeared. The very first V-1710 was purchased by the U.S. Navy as their GV-1710-2, and appears to have had an Allison serial of number 1, suggesting that they restarted numbering for the V-1710. The first V-1710 engine purchased by the USAAC was AAC 33-42, Allison Serial No. 2,

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4640-658: Is a consensus that the Federal Reserve System should have cut short the process of monetary deflation and banking collapse, by expanding the money supply and acting as lender of last resort . If they had done this, the economic downturn would have been far less severe and much shorter. Modern mainstream economists see the reasons in Insufficient spending, the money supply reduction, and debt on margin led to falling prices and further bankruptcies ( Irving Fisher 's debt deflation). The monetarist explanation

4785-533: Is a pre-cooled engine under development. At the April 2018 ILA Berlin Air Show , Munich -based research institute de:Bauhaus Luftfahrt presented a high-efficiency composite cycle engine for 2050, combining a geared turbofan with a piston engine core. The 2.87 m diameter, 16-blade fan gives a 33.7 ultra-high bypass ratio , driven by a geared low-pressure turbine but the high-pressure compressor drive comes from

4930-449: Is a twin-spool engine, allowing only two different speeds for the turbines. Pulsejets are mechanically simple devices that—in a repeating cycle—draw air through a no-return valve at the front of the engine into a combustion chamber and ignite it. The combustion forces the exhaust gases out the back of the engine. It produces power as a series of pulses rather than as a steady output, hence the name. The only application of this type of engine

5075-490: Is above and behind. In the Cessna 337 Skymaster , a push-pull twin-engine airplane, engine No. 1 is the one at the front of the fuselage, while engine No. 2 is aft of the cabin. Aircraft reciprocating (piston) engines are typically designed to run on aviation gasoline . Avgas has a higher octane rating than automotive gasoline to allow higher compression ratios , power output, and efficiency at higher altitudes. Currently

5220-453: Is bolted to the airframe : in a turboshaft, the engine does not provide any direct physical support to the helicopter's rotors. The rotor is connected to a transmission which is bolted to the airframe, and the turboshaft engine drives the transmission. The distinction is seen by some as slim, as in some cases aircraft companies make both turboprop and turboshaft engines based on the same design. A number of electrically powered aircraft, such as

5365-720: 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; one was used in the Wright Flyer , the aircraft that made the first controlled powered flight. However, the inherent disadvantages of the design soon became apparent, and the inline design was abandoned, becoming a rarity in modern aviation. For other configurations of aviation inline engine, such as X-engines , U-engines , H-engines , etc., see Inline engine (aeronautics) . Cylinders in this engine are arranged in two in-line banks, typically tilted 60–90 degrees apart from each other and driving

5510-430: Is of lesser concern, rocket engines can be useful because they produce very large amounts of thrust and weigh very little. A rocket turbine engine is a combination of two types of propulsion engines: a liquid-propellant rocket and a turbine jet engine. Its power-to-weight ratio is a little higher than a regular jet engine, and works at higher altitudes. For very high supersonic/low hypersonic flight speeds, inserting

5655-493: Is supported by the contrast in how the crisis progressed in, e.g., Britain, Argentina and Brazil, all of which devalued their currencies early and returned to normal patterns of growth relatively rapidly and countries which stuck to the gold standard , such as France or Belgium. Frantic attempts by individual countries to shore up their economies through protectionist policies – such as the 1930 U.S. Smoot–Hawley Tariff Act and retaliatory tariffs in other countries – exacerbated

5800-513: 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

5945-539: The 1932 election , Hoover was defeated by Franklin D. Roosevelt , who from 1933 pursued a series of " New Deal " policies and programs to provide relief and create jobs, including the Civilian Conservation Corps , Federal Emergency Relief Administration , Tennessee Valley Authority , and Works Progress Administration . Historians disagree on the effects of the New Deal, with some claiming that

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6090-586: The 578-DX propfan . Unlike the competing General Electric GE-36 UDF , the 578-DX was fairly conventional, having a reduction gearbox between the LP turbine and the propfan blades. Noise considerations, plus a significant reduction in the real cost of aviation fuel, brought the NASA funded program to a halt. In 1995, Allison tested a prototype lift fan for the Joint Strike Fighter Program and

6235-524: The Allison GT 404-4 turboshaft engine intended for trucks. Allison continued to work with General Motors on development of ceramic- turbine powered engines until the early 1990s. During their work they were able to engineer fairly stable automobile engines that were capable of burning a variety of fuels, such as gasoline, Diesel, kerosene, alcohol, vegetable oil, and coal powder. In the 1980s Allison collaborated with Pratt & Whitney on demonstrating

6380-618: The Allison J35 . The J35 was the primary powerplant for the F-84 Thunderjet and F-89 Scorpion , as well as appearing on numerous prototype designs. The J35 also finished production in 1955, by which point over 14,000 had been delivered. Allison also began development of a series of turboprop engines for the U.S. Navy, starting with the T38 and a "twinned" version as the T40 . The Navy

6525-616: The Concentrated Acetylene Company , was founded in September 1904 by James Allison, Percy C. "Fred" Avery and Carl G. Fisher . Avery was the holder of the patent for the product. This company was the predecessor of the Prest-O-Lite Company , a manufacturer of acetylene headlights. An explosion at the acetylene gas works in downtown Indianapolis caused the company to relocate out of town, near

6670-596: The Convair 580 turboprop passenger aircraft which was widely used by local service and regional airlines in the U.S. such as Allegheny Airlines , the original Frontier Airlines , North Central Airlines , as well as major carriers American , Eastern , United , and Pan-Am . Over the years a family of engines based on the T56 configuration was developed, culminating in the T406/ Allison AE1107 turboshaft for

6815-960: The Indianapolis Motor Speedway in Indianapolis . James Allison was the owner of the Indianapolis Speedway Team Company , a race car business in Indianapolis, Indiana. While it was founded as the Indianapolis Speedway Team Company, its name changed numerous times, first to the Allison Speedway Team Company, then the Allison Experimental Company and last as the Allison Engineering Company before becoming

6960-582: The New York Bank of United States – which produced panic and widespread runs on local banks, and the Federal Reserve sat idly by while banks collapsed. Friedman and Schwartz argued that, if the Fed had provided emergency lending to these key banks, or simply bought government bonds on the open market to provide liquidity and increase the quantity of money after the key banks fell, all the rest of

7105-527: The QinetiQ Zephyr , have been designed since the 1960s. Some are used as military drones . In France in late 2007, a conventional light aircraft powered by an 18 kW electric motor using lithium polymer batteries was flown, covering more than 50 kilometers (31 mi), the first electric airplane to receive a certificate of airworthiness . On 18 May 2020, the Pipistrel E-811 was

7250-684: The Rutan Quickie . The single-rotor engine was put into a Chevvron motor glider and into the Schleicher ASH motor-gliders. After the demise of MidWest, all rights were sold to Diamond of Austria, who have since developed a MkII version of the engine. As a cost-effective alternative to certified aircraft engines some Wankel engines, removed from automobiles and converted to aviation use, have been fitted in homebuilt experimental aircraft . Mazda units with outputs ranging from 100 horsepower (75 kW) to 300 horsepower (220 kW) can be

7395-484: The United Engine Corporation , Aviadvigatel and Klimov . Aeroengine Corporation of China was formed in 2016 with the merger of several smaller companies. The largest manufacturer of turboprop engines for general aviation is Pratt & Whitney. General Electric announced in 2015 entrance into the market. In this section, for clarity, the term "inline engine" refers only to engines with

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7540-790: The V-22 Osprey , the Allison AE2100 turboprop, used on newer models of the C-130 and the Allison/ Rolls-Royce AE 3007 turbofan which propels many regional airline aircraft, such as the Embraer ERJ 135 , ERJ 140 and ERJ 145 family of regional passenger jets that continue to be widely used in the airline industry. One of Allison's most successful projects is the Model 250 turboshaft/turboprop engine family, which

7685-539: The coming to power of Hitler's Nazi regime in January 1933. The world financial crisis now began to overwhelm Britain; investors around the world started withdrawing their gold from London at the rate of £2.5 million per day. Credits of £25 million each from the Bank of France and the Federal Reserve Bank of New York and an issue of £15 million fiduciary note slowed, but did not reverse,

7830-424: The gyroscopic effects of the heavy rotating engine produced handling problems in aircraft and the engines also consumed large amounts of oil since they used total loss lubrication, the oil being mixed with the fuel and ejected with the exhaust gases. Castor oil was used for lubrication, since it is not soluble in petrol, and the resultant fumes were nauseating to the pilots. Engine designers had always been aware of

7975-424: The oxygen necessary for fuel combustion comes from the air, while rockets carry an oxidizer (usually oxygen in some form) as part of the fuel load, permitting their use in space. A turbojet is a type of gas turbine engine that was originally developed for military fighters during World War II . A turbojet is the simplest of all aircraft gas turbines. It consists of a compressor to draw air in and compress it,

8120-447: The 1937 recession that interrupted it). The common view among most economists is that Roosevelt's New Deal policies either caused or accelerated the recovery, although his policies were never aggressive enough to bring the economy completely out of recession. Some economists have also called attention to the positive effects from expectations of reflation and rising nominal interest rates that Roosevelt's words and actions portended. It

8265-813: The British crisis. The financial crisis now caused a major political crisis in Britain in August 1931. With deficits mounting, the bankers demanded a balanced budget; the divided cabinet of Prime Minister Ramsay MacDonald's Labour government agreed; it proposed to raise taxes, cut spending, and most controversially, to cut unemployment benefits 20%. The attack on welfare was unacceptable to the Labour movement. MacDonald wanted to resign, but King George V insisted he remain and form an all-party coalition " National Government ". The Conservative and Liberals parties signed on, along with

8410-817: The Clerget 14F Diesel radial engine (1939) has the same power to weight ratio as a gasoline radial. Improvements in Diesel technology in automobiles (leading to much better power-weight ratios), the Diesel's much better fuel efficiency and the high relative taxation of AVGAS compared to Jet A1 in Europe have all seen a revival of interest in the use of diesels for aircraft. Thielert Aircraft Engines converted Mercedes Diesel automotive engines, certified them for aircraft use, and became an OEM provider to Diamond Aviation for their light twin. Financial problems have plagued Thielert, so Diamond's affiliate — Austro Engine — developed

8555-530: The Depression. Businessmen ignored the mounting national debt and heavy new taxes, redoubling their efforts for greater output to take advantage of generous government contracts. During World War I many countries suspended their gold standard in varying ways. There was high inflation from WWI, and in the 1920s in the Weimar Republic , Austria , and throughout Europe. In the late 1920s there

8700-469: The Dow returning to 294 (pre-depression levels) in April 1930, before steadily declining for years, to a low of 41 in 1932. At the beginning, governments and businesses spent more in the first half of 1930 than in the corresponding period of the previous year. On the other hand, consumers, many of whom suffered severe losses in the stock market the previous year, cut expenditures by 10%. In addition, beginning in

8845-489: The Federal Reserve did not act to limit the decline of the money supply was the gold standard . At that time, the amount of credit the Federal Reserve could issue was limited by the Federal Reserve Act , which required 40% gold backing of Federal Reserve Notes issued. By the late 1920s, the Federal Reserve had almost hit the limit of allowable credit that could be backed by the gold in its possession. This credit

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8990-442: The Great Depression is right, or the traditional Keynesian explanation that a fall in autonomous spending, particularly investment, is the primary explanation for the onset of the Great Depression. Today there is also significant academic support for the debt deflation theory and the expectations hypothesis that – building on the monetary explanation of Milton Friedman and Anna Schwartz – add non-monetary explanations. There

9135-642: The Great Depression. According to the U.S. Senate website, the Smoot–Hawley Tariff Act is among the most catastrophic acts in congressional history. Many economists have argued that the sharp decline in international trade after 1930 helped to worsen the depression, especially for countries significantly dependent on foreign trade. Most historians and economists blame the Act for worsening the depression by seriously reducing international trade and causing retaliatory tariffs in other countries. While foreign trade

9280-481: The New Deal prolonged the Great Depression, as they argue that National Industrial Recovery Act of 1933 and National Labor Relations Act of 1935 restricted competition and established price fixing. John Maynard Keynes did not think that the New Deal under Roosevelt single-handedly ended the Great Depression: "It is, it seems, politically impossible for a capitalistic democracy to organize expenditure on

9425-544: The U.K. economy, which experienced an economic downturn throughout most of the late 1920s, was less severely impacted by the shock of the depression than the U.S. By contrast, the German economy saw a similar decline in industrial output as that observed in the U.S. Some economic historians attribute the differences in the rates of recovery and relative severity of the economic decline to whether particular countries had been able to effectively devaluate their currencies or not. This

9570-490: The U.S. unemployment rate down below 10%. World War II had a dramatic effect on many parts of the American economy. Government-financed capital spending accounted for only 5% of the annual U.S. investment in industrial capital in 1940; by 1943, the government accounted for 67% of U.S. capital investment. The massive war spending doubled economic growth rates, either masking the effects of the Depression or essentially ending

9715-685: The United States, agricultural organizations sponsored programs to teach housewives how to optimize their gardens and to raise poultry for meat and eggs. Rural women made feed sack dresses and other items for themselves and their families and homes from feed sacks. In American cities, African American women quiltmakers enlarged their activities, promoted collaboration, and trained neophytes. Quilts were created for practical use from various inexpensive materials and increased social interaction for women and promoted camaraderie and personal fulfillment. Oral history provides evidence for how housewives in

9860-543: The United States, remained on the gold standard into 1932 or 1933, while a few countries in the so-called "gold bloc", led by France and including Poland, Belgium and Switzerland, stayed on the standard until 1935–36. According to later analysis, the earliness with which a country left the gold standard reliably predicted its economic recovery. For example, The UK and Scandinavia, which left the gold standard in 1931, recovered much earlier than France and Belgium, which remained on gold much longer. Countries such as China, which had

10005-638: The Wall Street crash, after which the slide continued for three years, which was accompanied by a loss of confidence in the financial system. By 1933, the U.S. unemployment rate had risen to 25 percent, about one-third of farmers had lost their land, and about half of the country's 25,000 banks had gone out of business. Many people, unable to pay mortgages or rent, became homeless and relied on begging or charities to feed themselves. The U.S. federal government initially did little to help. President Herbert Hoover , like many of his fellow Republicans , believed in

10150-574: The Wankel engine has been used in motor gliders where the compactness, light weight, and smoothness are crucially important. The now-defunct Staverton-based firm MidWest designed and produced single- and twin-rotor aero engines, the MidWest AE series . These engines were developed from the motor in the Norton Classic motorcycle . The twin-rotor version was fitted into ARV Super2s and

10295-592: The XV-1710-1, while Serial Nos. 3, 4, 5 were V-1710-4 engines for U.S. Navy airships, followed by a batch of 11 Air Corps engines purchased with FY-1934 funds (34-4 through 34-14) that covered Allison serials 6 through 16. After these the production race was on, totaling over 70,000 V-1710s. By this time the Army had become more interested in the design, and asked Allison to continue with a new "C" model. They had few funds of their own to invest, and Allison supported much of

10440-460: The banks would not have fallen after the large ones did, and the money supply would not have fallen as far and as fast as it did. With significantly less money to go around, businesses could not get new loans and could not even get their old loans renewed, forcing many to stop investing. This interpretation blames the Federal Reserve for inaction, especially the New York branch . One reason why

10585-465: The behavior of housewives. The common view among economic historians is that the Great Depression ended with the advent of World War II . Many economists believe that government spending on the war caused or at least accelerated recovery from the Great Depression, though some consider that it did not play a very large role in the recovery, though it did help in reducing unemployment. The rearmament policies leading up to World War II helped stimulate

10730-462: The collapse in global trade, contributing to the depression. By 1933, the economic decline pushed world trade to one third of its level compared to four years earlier. While the precise causes for the occurrence of the Great depression are disputed and can be traced to both global and national phenomena, its immediate origins are most conveniently examined in the context of the U.S. economy, from which

10875-533: The company to wither, so he asked Gillman to build a V-12 marine engine worthy of the Allison name. Gillman then proceeded to build an engine that relied on what was learned from building and modifying the venerable Liberty engine. Allison's company was sold to Captain Eddie Rickenbacker in 1927 for $ 700,000 after Allison moved to Florida. In 1929, shortly after the death of James Allison, the company

11020-500: The compression-ignition diesel engine is seldom used. Starting in the 1930s attempts were made to produce a practical aircraft diesel engine . In general, Diesel engines are more reliable and much better suited to running for long periods of time at medium power settings. The lightweight alloys of the 1930s were not up to the task of handling the much higher compression ratios of diesel engines, so they generally had poor power-to-weight ratios and were uncommon for that reason, although

11165-475: The crash was a mere symptom of more general economic trends of the time, which had already been underway in the late 1920s. A contrasting set of views, which rose to prominence in the later part of the 20th century, ascribes a more prominent role to failures of monetary policy . According to those authors, while general economic trends can explain the emergence of the downturn, they fail to account for its severity and longevity; they argue that these were caused by

11310-553: The creator could not afford the custom gearboxes and clutches required to handle the enormous torque generated by the engines. The car survives, without its engines, in Indiana , USA. In 1992 General Motors tried to sell Allison to concentrate on rebuilding automobile market share. Rolls-Royce attempted to buy the company in 1993, but General Motors opted for a management buyout instead for $ 370 million. In 1995 US authorities approved, with restrictions on Joint Strike Fighter Program ,

11455-625: The crisis, the U.S. Congress passed the Smoot–Hawley Tariff Act on 17 June 1930. The Act was ostensibly aimed at protecting the American economy from foreign competition by imposing high tariffs on foreign imports. The consensus view among economists and economic historians (including Keynesians , Monetarists and Austrian economists ) is that the passage of the Smoot–Hawley Tariff had, in fact, achieved an opposite effect to what

11600-593: The cylinders arranged evenly around the crankshaft, although some early engines, sometimes called semi-radials or fan configuration engines, had an uneven arrangement. The best known engine of this type is the Anzani engine, which was fitted to the Bleriot XI used for the first flight across the English Channel in 1909. This arrangement had the drawback of needing a heavy counterbalance for the crankshaft, but

11745-486: The cylinders in a circle around the crankcase, as in a radial engine, (see above), but the crankshaft is fixed to the airframe and the propeller is fixed to the engine case, so that the crankcase and cylinders rotate. The advantage of this arrangement is that a satisfactory flow of cooling air is maintained even at low airspeeds, retaining the weight advantage and simplicity of a conventional air-cooled engine without one of their major drawbacks. The first practical rotary engine

11890-633: The decade. The Depression had devastating economic effects on both wealthy and poor countries: all experienced drops in personal income , prices ( deflation ), tax revenues, and profits. International trade fell by more than 50%, and unemployment in some countries rose as high as 33%. Cities around the world , especially those dependent on heavy industry , were heavily affected. Construction virtually halted in many countries, and farming communities and rural areas suffered as crop prices fell by up to 60%. Faced with plummeting demand and few job alternatives, areas dependent on primary sector industries suffered

12035-408: The depression. Not all governments enforced the same measures of protectionism. Some countries raised tariffs drastically and enforced severe restrictions on foreign exchange transactions, while other countries reduced "trade and exchange restrictions only marginally": The gold standard was the primary transmission mechanism of the Great Depression. Even countries that did not face bank failures and

12180-469: The development out of their own pocket. The V-1710-C first flew on 14 December 1936 in the Consolidated A-11 A testbed. The V-1710-C6 completed the Army 150 hour Type Test on 23 April 1937, at 1,000 hp (750 kW), the first engine of any type to do so. By then all of the other Army engine projects had been cancelled or withdrawn, leaving the V-1710 as the only modern design available. It

12325-435: The domestic price level to decline ( deflation ). There is also consensus that protectionist policies, and primarily the passage of the Smoot–Hawley Tariff Act , helped to exacerbate, or even cause the Great Depression. Some economic studies have indicated that the rigidities of the gold standard not only spread the downturn worldwide, but also suspended gold convertibility (devaluing the currency in gold terms) that did

12470-402: The drop in demand. Monetarists believe that the Great Depression started as an ordinary recession, but the shrinking of the money supply greatly exacerbated the economic situation, causing a recession to descend into the Great Depression. Economists and economic historians are almost evenly split as to whether the traditional monetary explanation that monetary forces were the primary cause of

12615-427: The economies of Europe in 1937–1939. By 1937, unemployment in Britain had fallen to 1.5 million. The mobilization of manpower following the outbreak of war in 1939 ended unemployment. The American mobilization for World War II at the end of 1941 moved approximately ten million people out of the civilian labor force and into the war. This finally eliminated the last effects from the Great Depression and brought

12760-576: The end of the month. A large sell-off of stocks began in mid-October. Finally, on 24 October, Black Thursday , the American stock market crashed 11% at the opening bell. Actions to stabilize the market failed, and on 28 October, Black Monday, the market crashed another 12%. The panic peaked the next day on Black Tuesday, when the market saw another 11% drop. Thousands of investors were ruined, and billions of dollars had been lost; many stocks could not be sold at any price. The market recovered 12% on Wednesday but by then significant damage had been done. Though

12905-569: The end of the war, Allison found itself with a large production infrastructure that was no longer needed. For this reason, in 1947, the Army decided to take General Electric 's versions of Frank Whittle 's jet engines and give them to Allison to produce instead. The main production model was GE's 4,000 lbf (18 kN) I-40, produced as the Allison J33 . By the time production ended in 1955, Allison had produced over 7,000 J33s. Allison also took over GE's axial flow engine design, becoming

13050-581: The engine core is the bypass ratio. Low-bypass engines are preferred for military applications such as fighters due to high thrust-to-weight ratio, while high-bypass engines are preferred for civil use for good fuel efficiency and low noise. High-bypass turbofans are usually most efficient when the aircraft is traveling at 500 to 550 miles per hour (800 to 890 kilometres per hour), the cruise speed of most large airliners. Low-bypass turbofans can reach supersonic speeds, though normally only when fitted with afterburners . The term advanced technology engine refers to

13195-438: The engine works by having a coiled pipe in the combustion chamber that superheats the fuel (propane) before being injected into the air-fuel inlet. In the combustion chamber, the fuel/air mixture ignites and burns, creating thrust as it leaves through the exhaust pipe. Induction and compression of the fuel/air mixture is done both by the pressure of propane as it is injected, along with the sound waves created by combustion acting on

13340-415: The engine's heat-radiating surfaces to the air and tends to cancel reciprocating forces, radials tend to cool evenly and run smoothly. The lower cylinders, which are under the crankcase, may collect oil when the engine has been stopped for an extended period. If this oil is not cleared from the cylinders prior to starting the engine, serious damage due to hydrostatic lock may occur. Most radial engines have

13485-500: The explanations of the Keynesians and monetarists. The consensus among demand-driven theories is that a large-scale loss of confidence led to a sudden reduction in consumption and investment spending. Once panic and deflation set in, many people believed they could avoid further losses by keeping clear of the markets. Holding money became profitable as prices dropped lower and a given amount of money bought ever more goods, exacerbating

13630-503: The few women in the labor force, layoffs were less common in the white-collar jobs and they were typically found in light manufacturing work. However, there was a widespread demand to limit families to one paid job, so that wives might lose employment if their husband was employed. Across Britain, there was a tendency for married women to join the labor force, competing for part-time jobs especially. In France, very slow population growth, especially in comparison to Germany continued to be

13775-606: The first electric aircraft engine to be awarded a type certificate by EASA for use in general aviation . The E-811 powers the Pipistrel Velis Electro . Limited experiments with solar electric propulsion have been performed, notably the manned Solar Challenger and Solar Impulse and the unmanned NASA Pathfinder aircraft. Many big companies, such as Siemens, are developing high performance electric engines for aircraft use, also, SAE shows new developments in elements as pure Copper core electric motors with

13920-399: The first engines to use multiple spools —concentric shafts that are free to rotate at their own speed—to let the engine react more quickly to changing power requirements. Turbofans are coarsely split into low-bypass and high-bypass categories. Bypass air flows through the fan, but around the jet core, not mixing with fuel and burning. The ratio of this air to the amount of air flowing through

14065-505: The first week of June, 540 million in the second, and 150 million in two days, 19–20 June. Collapse was at hand. U.S. President Herbert Hoover called for a moratorium on payment of war reparations . This angered Paris, which depended on a steady flow of German payments, but it slowed the crisis down, and the moratorium was agreed to in July 1931. An International conference in London later in July produced no agreements but on 19 August

14210-606: The government tried to reshape private household consumption under the Four-Year Plan of 1936 to achieve German economic self-sufficiency. The Nazi women's organizations, other propaganda agencies and the authorities all attempted to shape such consumption as economic self-sufficiency was needed to prepare for and to sustain the coming war. The organizations, propaganda agencies and authorities employed slogans that called up traditional values of thrift and healthy living. However, these efforts were only partly successful in changing

14355-519: The home, or took boarders, did laundry for trade or cash, and did sewing for neighbors in exchange for something they could offer. Extended families used mutual aid—extra food, spare rooms, repair-work, cash loans—to help cousins and in-laws. In Japan, official government policy was deflationary and the opposite of Keynesian spending. Consequently, the government launched a campaign across the country to induce households to reduce their consumption, focusing attention on spending by housewives. In Germany,

14500-470: The initial crisis spread to the rest of the world. In the aftermath of World War I , the Roaring Twenties brought considerable wealth to the United States and Western Europe. Initially, the year 1929 dawned with good economic prospects: despite a minor crash on 25 March 1929, the market seemed to gradually improve through September. Stock prices began to slump in September, and were volatile at

14645-497: The intake stacks. It was intended as a power plant for personal helicopters and compact aircraft such as Microlights. A few aircraft have used rocket engines for main thrust or attitude control, notably the Bell X-1 and North American X-15 . Rocket engines are not used for most aircraft as the energy and propellant efficiency is very poor, but have been employed for short bursts of speed and takeoff. Where fuel/propellant efficiency

14790-563: The lack of an adequate response to the crises of liquidity that followed the initial economic shock of 1929 and the subsequent bank failures accompanied by a general collapse of the financial markets. After the Wall Street Crash of 1929 , when the Dow Jones Industrial Average dropped from 381 to 198 over the course of two months, optimism persisted for some time. The stock market rose in early 1930, with

14935-430: The many limitations of the rotary engine so when the static style engines became more reliable and gave better specific weights and fuel consumption, the days of the rotary engine were numbered. The Wankel is a type of rotary engine. The Wankel engine is about one half the weight and size of a traditional four-stroke cycle piston engine of equal power output, and much lower in complexity. In an aircraft application,

15080-521: The market entered a period of recovery from 14 November until 17 April 1930, the general situation had been a prolonged slump. From 17 April 1930 until 8 July 1932, the market continued to lose 89% of its value. Despite the crash, the worst of the crisis did not reverberate around the world until after 1929. The crisis hit panic levels again in December 1930, with a bank run on the Bank of United States ,

15225-414: The mid-1930s, a severe drought ravaged the agricultural heartland of the U.S. Interest rates dropped to low levels by mid-1930, but expected deflation and the continuing reluctance of people to borrow meant that consumer spending and investment remained low. By May 1930, automobile sales declined to below the levels of 1928. Prices, in general, began to decline, although wages held steady in 1930. Then

15370-433: The modern generation of jet engines. The principle is that a turbine engine will function more efficiently if the various sets of turbines can revolve at their individual optimum speeds, instead of at the same speed. The true advanced technology engine has a triple spool, meaning that instead of having a single drive shaft, there are three, in order that the three sets of blades may revolve at different speeds. An interim state

15515-423: The monetary base and by not injecting liquidity into the banking system to prevent it from crumbling, the Federal Reserve passively watched the transformation of a normal recession into the Great Depression. Friedman and Schwartz argued that the downward turn in the economy, starting with the stock market crash, would merely have been an ordinary recession if the Federal Reserve had taken aggressive action. This view

15660-463: The most common Avgas is 100LL. This refers to the octane rating (100 octane) and the lead content (LL = low lead, relative to the historic levels of lead in pre-regulation Avgas). Refineries blend Avgas with tetraethyllead (TEL) to achieve these high octane ratings, a practice that governments no longer permit for gasoline intended for road vehicles. The shrinking supply of TEL and the possibility of environmental legislation banning its use have made

15805-502: The most to make recovery possible. Every major currency left the gold standard during the Great Depression. The UK was the first to do so. Facing speculative attacks on the pound and depleting gold reserves , in September 1931 the Bank of England ceased exchanging pound notes for gold and the pound was floated on foreign exchange markets. Japan and the Scandinavian countries followed in 1931. Other countries, such as Italy and

15950-427: The most. The outbreak of World War II in 1939 ended the Depression, as it stimulated factory production, providing jobs for women as militaries absorbed large numbers of young, unemployed men. The precise causes for the Great Depression are disputed. One set of historians, for example, focuses on non-monetary economic causes. Among these, some regard the Wall Street crash itself as the main cause; others consider that

16095-582: The need to balance the national budget and was unwilling to implement expensive welfare spending . In 1930, Hoover signed the Smoot–Hawley Tariff Act , which taxed imports with the intention of encouraging buyers to purchase American products, which worsened the Depression because foreign governments retaliated with tariffs on American exports. In 1932, Hoover established the Reconstruction Finance Corporation , which offered loans to businesses and support to local governments. In

16240-404: The new AE300 turbodiesel , also based on a Mercedes engine. Competing new Diesel engines may bring fuel efficiency and lead-free emissions to small aircraft, representing the biggest change in light aircraft engines in decades. While military fighters require very high speeds, many civil airplanes do not. Yet, civil aircraft designers wanted to benefit from the high power and low maintenance that

16385-483: The physical volume of exports fall, but also the prices fell by about 1 ⁄ 3 as written. Hardest hit were farm commodities such as wheat, cotton, tobacco, and lumber. Governments around the world took various steps into spending less money on foreign goods such as: "imposing tariffs, import quotas, and exchange controls". These restrictions triggered much tension among countries that had large amounts of bilateral trade, causing major export-import reductions during

16530-483: The point of view of the pilot looking forward, so for example on a four-engine aircraft such as the Boeing 747 , engine No. 1 is on the left side, farthest from the fuselage, while engine No. 3 is on the right side nearest to the fuselage. In the case of the twin-engine English Electric Lightning , which has two fuselage-mounted jet engines one above the other, engine No. 1 is below and to the front of engine No. 2, which

16675-480: The policies prolonged the Depression instead of shortening it. Between 1929 and 1932, worldwide gross domestic product (GDP) fell by an estimated 15%; in the U.S., the Depression resulted in a 30% contraction in GDP. Recovery varied greatly around the world. Some economies, such as the U.S., Germany and Japan started to recover by the mid-1930s; others, like France, did not return to pre-shock growth rates until later in

16820-406: The political situation in Europe. In their book, A Monetary History of the United States , Milton Friedman and Anna J. Schwartz also attributed the recovery to monetary factors, and contended that it was much slowed by poor management of money by the Federal Reserve System . Chairman of the Federal Reserve (2006–2014) Ben Bernanke agreed that monetary factors played important roles both in

16965-432: The power-to-weight ratio is very important, making the Wankel engine a good choice. Because the engine is typically constructed with an aluminium housing and a steel rotor, and aluminium expands more than steel when heated, a Wankel engine does not seize when overheated, unlike a piston engine. This is an important safety factor for aeronautical use. Considerable development of these designs started after World War II , but at

17110-799: The purchase of Allison by Rolls-Royce. The price was $ 525 million. In the year 2000, some of these restrictions were alleviated, and in 2001 the US government chose the F-35 with Rolls-Royce LiftFan and Pratt & Whitney F135 engines. Allison was also a partner with General Electric and Rolls-Royce on the F136 Fighter Engine Team. Aircraft engine In commercial aviation the major Western manufacturers of turbofan engines are Pratt & Whitney (a subsidiary of Raytheon Technologies ), General Electric , Rolls-Royce , and CFM International (a joint venture of Safran Aircraft Engines and General Electric). Russian manufacturers include

17255-617: The race track in Speedway, Indiana . Allison and Fisher raced automobiles at that track, each owning a race car team. This hobby resulted in Allison building a shop at the track in Speedway where he maintained his fleet of race cars. This shop became the site for Allison Plant #1. Fisher and Allison sold their interest in Prest-O-Lite to Union Carbide for $ 9,000,000. Allison started as an engine and car "hot rodding" company servicing

17400-434: The scale necessary to make the grand experiments which would prove my case—except in war conditions." According to Christina Romer , the money supply growth caused by huge international gold inflows was a crucial source of the recovery of the United States economy, and that the economy showed little sign of self-correction. The gold inflows were partly due to devaluation of the U.S. dollar and partly due to deterioration of

17545-439: The time the aircraft industry favored the use of turbine engines. It was believed that turbojet or turboprop engines could power all aircraft, from the largest to smallest designs. The Wankel engine did not find many applications in aircraft, but was used by Mazda in a popular line of sports cars . The French company Citroën had developed Wankel powered RE-2  [ fr ] helicopter in 1970's. In modern times

17690-414: The two crankshafts geared together. This type of engine has one or more rows of cylinders arranged around a centrally located crankcase . Each row generally has an odd number of cylinders to produce smooth operation. A radial engine has only one crank throw per row and a relatively small crankcase, resulting in a favorable power-to-weight ratio . Because the cylinder arrangement exposes a large amount of

17835-448: The use of a glow plug ) powered by glow fuel , a mixture of methanol , nitromethane , and lubricant. Electrically powered model airplanes and helicopters are also commercially available. Small multicopter UAVs are almost always powered by electricity, but larger gasoline-powered designs are under development. Great Depression The Great Depression was a severe global economic downturn from 1929 to 1939. The period

17980-476: The world, recovery from the Great Depression began in 1933. In the U.S., recovery began in early 1933, but the U.S. did not return to 1929 GNP for over a decade and still had an unemployment rate of about 15% in 1940, albeit down from the high of 25% in 1933. There is no consensus among economists regarding the motive force for the U.S. economic expansion that continued through most of the Roosevelt years (and

18125-673: The world. The financial crisis escalated out of control in mid-1931, starting with the collapse of the Credit Anstalt in Vienna in May. This put heavy pressure on Germany, which was already in political turmoil. With the rise in violence of National Socialist ('Nazi') and Communist movements, as well as investor nervousness at harsh government financial policies, investors withdrew their short-term money from Germany as confidence spiraled downward. The Reichsbank lost 150 million marks in

18270-778: The worldwide economic decline and eventual recovery. Bernanke also saw a strong role for institutional factors, particularly the rebuilding and restructuring of the financial system, and pointed out that the Depression should be examined in an international perspective. Women's primary role was as housewives; without a steady flow of family income, their work became much harder in dealing with food and clothing and medical care. Birthrates fell everywhere, as children were postponed until families could financially support them. The average birthrate for 14 major countries fell 12% from 19.3 births per thousand population in 1930, to 17.0 in 1935. In Canada, half of Roman Catholic women defied Church teachings and used contraception to postpone births. Among

18415-399: The years after the war, the drawbacks of the turbojet gradually became apparent. Below about Mach 2, turbojets are very fuel inefficient and create tremendous amounts of noise. Early designs also respond very slowly to power changes, a fact that killed many experienced pilots when they attempted the transition to jets. These drawbacks eventually led to the downfall of the pure turbojet, and only

18560-658: Was a scramble to deflate prices to get the gold standard's conversation rates back on track to pre-WWI levels, by causing deflation and high unemployment through monetary policy. In 1933 FDR signed Executive Order 6102 and in 1934 signed the Gold Reserve Act . The two classic competing economic theories of the Great Depression are the Keynesian (demand-driven) and the Monetarist explanation. There are also various heterodox theories that downplay or reject

18705-478: Was a small part of overall economic activity in the U.S. and was concentrated in a few businesses like farming, it was a much larger factor in many other countries. The average ad valorem (value based) rate of duties on dutiable imports for 1921–1925 was 25.9% but under the new tariff it jumped to 50% during 1931–1935. In dollar terms, American exports declined over the next four years from about $ 5.2 billion in 1929 to $ 1.7 billion in 1933; so, not only did

18850-485: Was characterized by high rates of unemployment and poverty; drastic reductions in liquidity , industrial production, and trade; and widespread bank and business failures around the world. The economic contagion began in 1929 in the United States , the largest economy in the world, with the devastating Wall Street stock market crash of October 1929 often considered the beginning of the Depression. The Depression

18995-474: Was endorsed in 2002 by Federal Reserve Governor Ben Bernanke in a speech honoring Friedman and Schwartz with this statement: Let me end my talk by abusing slightly my status as an official representative of the Federal Reserve. I would like to say to Milton and Anna: Regarding the Great Depression, you're right. We did it. We're very sorry. But thanks to you, we won't do it again. The Federal Reserve allowed some large public bank failures – particularly that of

19140-426: Was given by American economists Milton Friedman and Anna J. Schwartz . They argued that the Great Depression was caused by the banking crisis that caused one-third of all banks to vanish, a reduction of bank shareholder wealth and more importantly monetary contraction of 35%, which they called "The Great Contraction ". This caused a price drop of 33% ( deflation ). By not lowering interest rates, by not increasing

19285-500: Was in the form of Federal Reserve demand notes. A "promise of gold" is not as good as "gold in the hand", particularly when they only had enough gold to cover 40% of the Federal Reserve Notes outstanding. During the bank panics, a portion of those demand notes was redeemed for Federal Reserve gold. Since the Federal Reserve had hit its limit on allowable credit, any reduction in gold in its vaults had to be accompanied by

19430-446: Was intended. It exacerbated the Great Depression by preventing economic recovery after domestic production recovered, hampering the volume of trade; still there is disagreement as to the precise extent of the Act's influence. In the popular view, the Smoot–Hawley Tariff was one of the leading causes of the depression. In a 1995 survey of American economic historians, two-thirds agreed that the Smoot–Hawley Tariff Act at least worsened

19575-579: Was interested only in the T40, but the complexities of the drive shaft arrangement doomed the engine and the project was eventually cancelled. Allison tried again with the T56 , basically an enlarged T38 with the power of the T40, and was eventually rewarded when this engine was selected to power the C-130 Hercules . Allison turboprop engines were also used to re-engine Convair prop airliners which resulted in

19720-595: Was invested in equipping the V-1710 with a complex two-stage supercharger, and when placed in aircraft designs like the P-39 or P-40, which lacked the room for a turbocharger, the engine suffered tremendously at higher altitudes. It was for this reason in particular that the V-1710 was later removed from the P-51 Mustang and replaced with the Rolls-Royce Merlin . With the need for the V-1710 winding down at

19865-523: Was preceded by a period of industrial growth and social development known as the " Roaring Twenties ". Much of the profit generated by the boom was invested in speculation , such as on the stock market , which resulted in growing wealth inequality . Banks were subject to minimal regulation under laissez-faire economic policies, resulting in loose lending and widespread debt. By 1929, declining spending had led to reductions in manufacturing output and rising unemployment . Share values continued to rise until

20010-773: Was purchased by the Fisher brothers . The Fishers sold the company to General Motors , who owned it for most of its history. The Allison Engine Company was acquired in 1995 by Rolls-Royce plc , and became the Rolls-Royce Corporation subsidiary. In the late 1920s the United States Army funded the development of a series of high-power engines, as part of its hyper engine series, which it intended to produce on Continental Motors ' production lines. Allison's manager, Norman Gilman, decided to experiment with his own high-power cylinder design. Allison's engine became Manufacturer Serial No. 1, AAC S/N 25-521. It

20155-485: Was soon found as the primary power plant of the new generation of United States Army Air Corps (USAAC) fighters, the P-38 Lightning , P-39 Airacobra and P-40 Warhawk . The Army had been leaning heavily towards exhaust-driven turbochargers , instead of the more common mechanically driven superchargers , favoring the theoretical advantage of using the otherwise wasted energy in the exhaust. Thus, little effort

20300-597: Was started by the company in the early 1960s, when helicopters started to be powered by turbine, rather than reciprocating, engines. Allison turbine engines were used to power Bell 206 Jet Ranger and Long Ranger helicopters as well as the initial version of the Sikorsky S-76 helicopter. In the mid-1970s the Allison Division of General Motors Corporation in Detroit designed ceramic components into

20445-572: Was the Gnome Omega designed by the Seguin brothers and first flown in 1909. Its relative reliability and good power to weight ratio changed aviation dramatically. Before the first World War most speed records were gained using Gnome-engined aircraft, and in the early years of the war rotary engines were dominant in aircraft types for which speed and agility were paramount. To increase power, engines with two rows of cylinders were built. However,

20590-426: Was the German unmanned V1 flying bomb of World War II . Though the same engines were also used experimentally for ersatz fighter aircraft, the extremely loud noise generated by the engines caused mechanical damage to the airframe that was sufficient to make the idea unworkable. The Gluhareff Pressure Jet (or tip jet) is a type of jet engine that, like a valveless pulsejet, has no moving parts. Having no moving parts,

20735-592: Was the X-4520, a 24-cylinder air-cooled 4-bank “X” configured engine designed by the Army Air Corps and built by the Allison Engineering Company in 1925. The result was presented to the Army in 1928, which turned down the development proposal. In 1929, shortly after the death of James Allison, the company was purchased by the Fisher brothers, who instructed it to use the cylinder design for a six-cylinder engine for

20880-470: Was the rollback of those same reflationary policies that led to the interruption of a recession beginning in late 1937. One contributing policy that reversed reflation was the Banking Act of 1935 , which effectively raised reserve requirements, causing a monetary contraction that helped to thwart the recovery. GDP returned to its upward trend in 1938. A revisionist view among some economists holds that

21025-487: Was used to avoid the spark plugs oiling up. In military aircraft designs, the large frontal area of the engine acted as an extra layer of armor for the pilot. Also air-cooled engines, without vulnerable radiators, are slightly less prone to battle damage, and on occasion would continue running even with one or more cylinders shot away. However, the large frontal area also resulted in an aircraft with an aerodynamically inefficient increased frontal area. Rotary engines have

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