67-548: The Allison T56 is an American single-shaft, modular design military turboprop with a 14-stage axial flow compressor driven by a four-stage turbine. It was originally developed by the Allison Engine Company for the Lockheed C-130 Hercules transport entering production in 1954. It has been a Rolls-Royce product since 1995 when Allison was acquired by Rolls-Royce. The commercial version
134-403: A U.S. Army requirement. Lockheed internal designation GL298-7 involved a C-130E Hercules that was re-engined with 4,591 shp (3,424 kW) 501-M7B turboprops. The 501-M7B produced more power than the normally installed, 3,755 shp (2,800 kW) T56-A-7 engines by about 20% (though the 501-M7B was limited to 4,200 shp (3,100 kW) to avoid additional structural changes), because
201-630: A memorandum of understanding (MoU) with Messerschmitt-Bölkow-Blohm (MBB) of West Germany and the China National Aero-Technology Import & Export Corporation (CATIC) to work on a version of the MPC 75 regional aircraft to be powered by a T406-derived propfan . In 1990, Allison studied a 9,000 shp (6,700 kW) propfan powerplant driving 8.5 ft diameter (2.6 m) contra-rotating propellers to power Euroflag 's proposed military airlift aircraft. Also,
268-546: A common core with the AE 3007 turbofan and AE 2100 turboprop series of engines, both of which have sold in the thousands of copies. 44-46 percent of parts are common between the T406 and the AE 3007, while about 76 percent of parts are common between the T406 and the AE 2100. In addition, Allison attempted to develop other types of engines based on the T406. In 1988, the company signed
335-406: A constant-speed propeller increase their pitch as aircraft speed increases. Another benefit of this type of propeller is that it can also be used to generate reverse thrust to reduce stopping distance on the runway. Additionally, in the event of an engine failure, the propeller can be feathered , thus minimizing the drag of the non-functioning propeller. While the power turbine may be integral with
402-416: A large amount of air by a small degree than a small amount of air by a large degree, a low disc loading (thrust per unit disc area) increases the aircraft's energy efficiency , and this reduces the fuel use. Propellers work well until the flight speed of the aircraft is high enough that the airflow past the blade tips reaches the speed of sound. Beyond that speed, the proportion of the power that drives
469-591: A test-bed not intended for production. It first flew on 20 September 1945. From their experience with the Trent, Rolls-Royce developed the Rolls-Royce Clyde , the first turboprop engine to receive a type certificate for military and civil use, and the Dart , which became one of the most reliable turboprop engines ever built. Dart production continued for more than fifty years. The Dart-powered Vickers Viscount
536-482: A turboprop powerplant. In early 1960, two Allison YT56-A-6 experimental turbine engines without propellers were added next to existing propulsion engines on flight tests of a Lockheed NC-130B 58-0712 aircraft. The YT56-A-6 produced pressurized air for blowing over control surfaces to demonstrate boundary layer control (BLC), which helped to enable short takeoff and landing (STOL) performance. In 1963, Lockheed and Allison designed another STOL demonstrator, this time for
603-429: Is a turbine engine that drives an aircraft propeller . A turboprop consists of an intake , reduction gearbox , compressor , combustor , turbine , and a propelling nozzle . Air enters the intake and is compressed by the compressor. Fuel is then added to the compressed air in the combustor, where the fuel-air mixture then combusts . The hot combustion gases expand through the turbine stages, generating power at
670-752: Is based on the Allison T56 turboprop from the P-3 and the C-130 , with the free power turbine of the Allison T701 turboshaft from the defunct Heavy Lift Helicopter program . It was selected over the Pratt & Whitney PW3000 and General Electric GE27 competing for the US Army's Modern Technology Demonstrator Engine program. The T406 began flight testing on 19 March 1989. The T406/AE 1107C Liberty shares
737-407: Is designated 501-D . Over 18,000 engines have been produced since 1954, logging over 200 million flying hours. The T56 turboprop, evolved from Allison's previous T38 series, was first flown in the nose of a B-17 test-bed aircraft in 1954. One of the first flight-cleared YT-56 engines was installed in a C-130 nacelle on Lockheed's Super Constellation test aircraft in early 1954. Originally fitted to
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#1732772159513804-482: Is normally a constant-speed (variable pitch) propeller type similar to that used with larger aircraft reciprocating engines , except that the propeller-control requirements are very different. Due to the turbine engine's slow response to power inputs, particularly at low speeds, the propeller has a greater range of selected travel in order to make rapid thrust changes, notably for taxi, reverse, and other ground operations. The propeller has 2 modes, Alpha and Beta. Alpha
871-494: Is sacrificed in favor of shaft power, which is obtained by extracting additional power (beyond that necessary to drive the compressor) from turbine expansion. Owing to the additional expansion in the turbine system, the residual energy in the exhaust jet is low. Consequently, the exhaust jet produces about 10% of the total thrust. A higher proportion of the thrust comes from the propeller at low speeds and less at higher speeds. Turboprops have bypass ratios of 50–100, although
938-404: Is the mode for all flight operations including takeoff. Beta, a mode typically consisting of zero to negative thrust, is used for all ground operations aside from takeoff. The Beta mode is further broken down into 2 additional modes, Beta for taxi and Beta plus power. Beta for taxi as the name implies is used for taxi operations and consists of all pitch ranges from the lowest alpha range pitch, all
1005-598: The Allison Engine Company as the 501-D and powered the Lockheed C-130 Hercules . Later variants (Series II, III, and IV) and the Series 3.5 engine enhancement kit gave increased performance through design refinements. Further derivatives of the 501-D/T56 were produced as turboshafts for helicopters including a variant designated T701 that was developed for the canceled Boeing Vertol XCH-62 project. Data from Rolls-Royce. Related development Comparable engines Related lists Turboprop A turboprop
1072-761: The Lockheed C-130 Hercules military transport aircraft , the T56 was also installed on the Lockheed P-3 Orion maritime patrol aircraft (MPA), Grumman E-2 Hawkeye airborne early warning (AEW) aircraft, and Grumman C-2 Greyhound carrier onboard delivery (COD) aircraft, as well as civilian airliners such as the Lockheed Electra and the Convair 580 . The T56-A-1 delivered to Lockheed in May, 1953, produced only 3,000 shp (2,237 kW), compared to
1139-634: The P-3 Orion , and the C-130 Hercules military transport aircraft. The first turbine-powered, shaft-driven helicopter was the Kaman K-225 , a development of Charles Kaman 's K-125 synchropter , which used a Boeing T50 turboshaft engine to power it on 11 December 1951. December 1963 saw the first delivery of Pratt & Whitney Canada's PT6 turboprop engine for the then Beechcraft 87, soon to become Beechcraft King Air . 1964 saw
1206-841: The Piper Meridian , Socata TBM , Pilatus PC-12 , Piaggio P.180 Avanti , Beechcraft King Air and Super King Air . In April 2017, there were 14,311 business turboprops in the worldwide fleet. Between 2012 and 2016, the ATSB observed 417 events with turboprop aircraft, 83 per year, over 1.4 million flight hours: 2.2 per 10,000 hours. Three were "high risk" involving engine malfunction and unplanned landing in single‑engine Cessna 208 Caravans , four "medium risk" and 96% "low risk". Two occurrences resulted in minor injuries due to engine malfunction and terrain collision in agricultural aircraft and five accidents involved aerial work: four in agriculture and one in an air ambulance . Jane's All
1273-614: The Tupolev Tu-114 can reach 470 kn (870 km/h; 540 mph). Large military aircraft , like the Tupolev Tu-95 , and civil aircraft , such as the Lockheed L-188 Electra , were also turboprop powered. The Airbus A400M is powered by four Europrop TP400 engines, which are the second most powerful turboprop engines ever produced, after the 11 MW (15,000 hp) Kuznetsov NK-12 . In 2017,
1340-550: The United States Congress restricted CIP work to reliability and maintainability improvements instead of performance improvements. The Series IV derivatives were finally developed in the 1980s after being approved for a U.S. Air Force engine model derivative program (EMDP) in the 1979 fiscal year budget. Series IV engines include the Air Force EMDP T56-A-100 demonstrator, model T56-A-101 for
1407-416: The natural gas -fueled 501-K5 and the liquid-fueled 501-K14. The air-cooled Series III turbines included the natural gas-fueled 501-K13 and the liquid-fueled 501-K15. A marinized turboshaft version of the 501-K is used to generate electrical power onboard all the U.S. Navy's cruisers ( Ticonderoga class ) and almost all of its destroyers ( Arleigh Burke class ). During the late 1960s, the U.S. Navy funded
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#17327721595131474-533: The 1107C used on the Osprey which would be named the 1107F. At the same time as increasing power from 5,000 to 7,000 horsepower, the 1107C is a known element in tiltrotor aircraft with its two decades of prior use which lowers sustainment costs and de-risks the project. The V-22's T406 powerplants are housed in wing-tip tilting nacelles, allowing the distinctive flight characteristics of the V-22. For take off and landing
1541-614: The 570-K were the elimination of compressor bleed air and replacing the XT701's titanium compressor case with a steel case. The 570-K was then adapted to the 6,000 shp (4,500 kW) 501-M78B demonstration engine, which Lockheed flew on a Grumman Gulfstream II as part of the NASA Propfan Test Assessment Program in the late 1980s. The 501-M78B had the same 13-stage compressor, combustor, 2-stage gas producer turbine, and 2-stage free power turbine used on
1608-750: The Air Force's C-130 aircraft, T56-A-427 for NAVAIR 's E-2C and C-2A aircraft, 501-D39 for the Lockheed L-100 aircraft, and the 501-K34 marine turboshaft for NAVSEA . The T56-A-427 was capable of 5,912 prop shp (4,409 kW), but it was torque -limited to 5,250 prop shp (3,910 kW). The Lockheed Martin C-130J Super Hercules which first flew in 1996, has the T56 replaced by the Rolls-Royce AE 2100 , which uses dual FADECs (Full Authority Digital Engine Control) to control
1675-621: The E-2 Hawkeye, C-2 Greyhound, and older-model C-130 Hercules aircraft, and will be adopted on the P-3 Orion. Production of the T56 engine is expected to continue to at least 2026, with the U.S. Naval Air Systems Command (NAVAIR) order in 2019 of 24 additional E-2D Advanced Hawkeyes (AHEs) powered by the T56-A-427A engine variant. The T56/Model 501 engine has been used in a number of experimental efforts, and as something other than
1742-647: The HLH, but funding of the HLH program was canceled in August 1975, when the triple-turbine, tandem-rotor helicopter prototype had reached 95% completion. Following the HLH program cancellation, Allison decided in early 1976 to apply the XT701 engine technology into a new industrial gas turbine product, the 570-K. The industrial engine, which entered production in the late 1970s, was derated to 7,170 shp (5,350 kW) and adapted for marine, gas compressor, and electrical power generation variants. The only major changes made for
1809-634: The MT7 gas turbines that will be used to power the Ship-to-Shore Connector are a derived design of the T406. Production continued by Rolls-Royce after it acquired Allison in 1995 to establish a North American subsidiary. In 2009, the Government Accountability Office (GAO) found that the engines failed after less than 400 hours of service, as compared to the estimated life of 500–600 hours. Multiple updates to
1876-525: The Series II, which was introduced in 1958 and had an increased power rating of 3,755 prop shp (2,800 kW), and the Series III, which came out in 1964 and had another power increase to 4,591 prop shp (3,424 kW). The Series II and III derivatives were developed under military component improvement programs (CIP). By 1965, Allison was proposing the development of Series IV derivatives, but in 1968,
1943-533: The Soviet Union had the technology to create the airframe for a jet-powered strategic bomber comparable to Boeing's B-52 Stratofortress , they instead produced the Tupolev Tu-95 Bear, powered with four Kuznetsov NK-12 turboprops, mated to eight contra-rotating propellers (two per nacelle) with supersonic tip speeds to achieve maximum cruise speeds in excess of 575 mph, faster than many of
2010-458: The T56 produces approximately 750 lbf (3,336.17 N) residual thrust from its exhaust. Over the years, there have been a number of engine development versions, which are grouped by series numbers. The Series I collection of derivatives came out in 1954, producing a sea-level static power rating of 3,460 propeller shp (2,580 kW) at a 59 °F (15 °C; 519 °R; 288 K) ambient temperature. Successive engine follow-ups included
2077-495: The V-22 engine contract anyway. On 24 December 1985, the U.S. Navy selected Allison's engine for full-scale engine development and production on the U.S. Marine Corps 's V-22 Osprey. Before the engine was given its United States military aircraft engine designation of T406, it was known as the Model 501-M80C. The Navy and Allison signed a formal contract on 2 May 1986, and the first engine to test ran six months after. The T406
Allison T56 - Misplaced Pages Continue
2144-669: The World's Aircraft . 2005–2006. AE 1107C The Rolls-Royce T406 (company designation AE 1107 ) is a turboshaft engine developed by Allison Engine Company (now part of Rolls-Royce ) that powers the Bell Boeing V-22 Osprey tiltrotor . The engine delivers 6,000 shp (4,470 kW). In 1982, Detroit Diesel Allison (DDA) prepared a new engine design to enter the United States Army 's Modern Technology Demonstrator Engine (MTDE) competition, which
2211-467: The XT701 and 570-K, but it was connected through a 6.797 reduction ratio gearbox to a 9 ft diameter (2.7 m) Hamilton Standard single-rotation propfan , containing propfan blades that were swept back 45 degrees at the tips. The T56 has been developed extensively throughout its production run, the many variants are described by the manufacturer as belonging to four main series groups. Initial civil variants (Series I) were designed and produced by
2278-438: The compressor guide vanes that internal testing showed could improve surge margin by 0.8% at sea level and 3% at altitude. The second is the discovery that a temperature sensor at the inlet of the compressor sends incorrect readings leading to 2.5% out of 4% steady power shortfall at the compressors correct rotational speed again correctable with a software fix. In addition, Bell Boeing is developing an inlet barrier system to reduce
2345-417: The compressor intake is at the aft of the engine, and the exhaust is situated forward, reducing the distance between the turbine and the propeller. Unlike the small-diameter fans used in turbofan engines, the propeller has a large diameter that lets it accelerate a large volume of air. This permits a lower airstream velocity for a given amount of thrust. Since it is more efficient at low speeds to accelerate
2412-459: The control system. The turboprop system consists of 3 propeller governors , a governor, and overspeed governor, and a fuel-topping governor. The governor works in much the same way a reciprocating engine propeller governor works, though a turboprop governor may incorporate beta control valve or beta lift rod for beta operation and is typically located in the 12 o'clock position. There are also other governors that are included in addition depending on
2479-541: The development of its XCH-62 heavy-lift helicopter (HLH) program for the U.S. Army, using the Allison 501-M62B turboshaft engine. The 501-M62B had a 13-stage compressor based on the 501-M24 demonstrator engine, which was a fixed single-shaft engine with an increased overall pressure ratio and a variable-geometry compressor, and it had an annular combustor based on the T56-A-18 and other development programs. The turbine
2546-543: The development of the T56-A-18 engine, which introduced a new gearbox compared with the early gearbox on the T56-A-7. The 50-hour preliminary flight rating test (PFRT) was completed for the T56-A-18 in 1968. In the early 1970s, Boeing Vertol selected Allison (at that time known as the Detroit Diesel Allison Division (DDAD) of General Motors ) to power a dynamic-system test rig (DSTR) supporting
2613-555: The engine achieved a power output of over 8,800 shp (6,600 kW) during ground testing. The Block 3 turbine became standard in July 2012 for new production models. By September 2012, all older engines that were undergoing regular maintenance were systematically upgraded to the Block 3 turbine. Engines with a future planned block 4 upgrade would be expected to deliver nearly 10,000 horsepower (7,500 kilowatts). An ongoing problem with
2680-495: The engine platform in 2012-2013 have increased the lifespan significantly. In April 2012, the United States Department of Defense (DoD) ordered 70 AE 1107C engines for the Osprey, with options for up to 268 engines. Rolls-Royce introduced a Block 3 turbine upgrade, which replaced the old turbine design with sturdier and more efficient components. The upgrade increased engine power by at least 17 percent, and
2747-531: The engines and propellers. It drives six-bladed scimitar propellers from Dowty Rotol . The T56 Series 3.5, an engine enhancement program to reduce fuel consumption and decrease temperatures, was approved in 2013 for the National Oceanic and Atmospheric Administration (NOAA) WP-3D "Hurricane Hunter" aircraft. After eight years of development and marketing efforts by Rolls-Royce, the T56 Series 3.5
Allison T56 - Misplaced Pages Continue
2814-407: The engines was their propensity for surging or stalling with 68 incidents reported between 2003 and October 2016 though this rate had reduced after the introduction of the Block 3 engine version. The US Naval Air Systems Command intends to award Rolls-Royce two contracts to examine the effectiveness of proposed reliability improvements, the first is a software tweak to the engine management software for
2881-499: The first jet aircraft and comparable to jet cruising speeds for most missions. The Bear would serve as their most successful long-range combat and surveillance aircraft and symbol of Soviet power projection through to the end of the 20th century. The USA used turboprop engines with contra-rotating propellers, such as the Allison T40 , on some experimental aircraft during the 1950s. The T40-powered Convair R3Y Tradewind flying-boat
2948-564: The first deliveries of the Garrett AiResearch TPE331 , (now owned by Honeywell Aerospace ) on the Mitsubishi MU-2 , making it the fastest turboprop aircraft for that year. In contrast to turbofans , turboprops are most efficient at flight speeds below 725 km/h (450 mph; 390 knots) because the jet velocity of the propeller (and exhaust) is relatively low. Modern turboprop airliners operate at nearly
3015-570: The gas generator section, many turboprops today feature a free power turbine on a separate coaxial shaft. This enables the propeller to rotate freely, independent of compressor speed. Alan Arnold Griffith had published a paper on compressor design in 1926. Subsequent work at the Royal Aircraft Establishment investigated axial compressor-based designs that would drive a propeller. From 1929, Frank Whittle began work on centrifugal compressor-based designs that would use all
3082-460: The gas power produced by the engine for jet thrust. The world's first turboprop was designed by the Hungarian mechanical engineer György Jendrassik . Jendrassik published a turboprop idea in 1928, and on 12 March 1929 he patented his invention. In 1938, he built a small-scale (100 Hp; 74.6 kW) experimental gas turbine. The larger Jendrassik Cs-1 , with a predicted output of 1,000 bhp,
3149-470: The introduction of air cooling in the turbine's first-stage blade and the first and second-stage vanes allowed for an increase in the turbine inlet temperature. In 1963, an aeroderivative line of industrial gas turbines based on the T56 was introduced in under the 501-K name. The 501-K is offered as a single-shaft version for constant speed applications and as a two-shaft version for variable-speed, high-torque applications. Series II standard turbines included
3216-406: The model, such as an overspeed and fuel topping governor on a Pratt & Whitney Canada PT6 , and an under-speed governor on a Honeywell TPE331 . The turboprop is also distinguished from other kinds of turbine engine in that the fuel control unit is connected to the governor to help dictate power. To make the engine more compact, reverse airflow can be used. On a reverse-flow turboprop engine,
3283-671: The most widespread turboprop airliners in service were the ATR 42 / 72 (950 aircraft), Bombardier Q400 (506), De Havilland Canada Dash 8 -100/200/300 (374), Beechcraft 1900 (328), de Havilland Canada DHC-6 Twin Otter (270), Saab 340 (225). Less widespread and older airliners include the BAe Jetstream 31 , Embraer EMB 120 Brasilia , Fairchild Swearingen Metroliner , Dornier 328 , Saab 2000 , Xian MA60 , MA600 and MA700 , Fokker 27 and 50 . Turboprop business aircraft include
3350-416: The pilot not being able to see out of the rear of the aircraft for backing and the amount of debris reverse stirs up, manufacturers will often limit the speeds beta plus power may be used and restrict its use on unimproved runways. Feathering of these propellers is performed by the propeller control lever. The constant-speed propeller is distinguished from the reciprocating engine constant-speed propeller by
3417-403: The point of exhaust. Some of the power generated by the turbine is used to drive the compressor and electric generator . The gases are then exhausted from the turbine. In contrast to a turbojet or turbofan , the engine's exhaust gases do not provide enough power to create significant thrust, since almost all of the engine's power is used to drive the propeller. Exhaust thrust in a turboprop
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#17327721595133484-540: The power loss from the engine ingesting dust and sand particles to supplement the engines existing centrifugal based particle separators as they can only do so much to improve the quality of air they receive. In October 2021, Bell and Rolls-Royce jointly announced that the Bell V-280 Valor powerplant would switch from the General Electric T64 turboshaft used on the prototype to a derivative of
3551-494: The propeller that is converted to propeller thrust falls dramatically. For this reason turboprop engines are not commonly used on aircraft that fly faster than 0.6–0.7 Mach , with some exceptions such as the Tupolev Tu-95 . However, propfan engines, which are very similar to turboprop engines, can cruise at flight speeds approaching 0.75 Mach. To maintain propeller efficiency across a wide range of airspeeds, turboprops use constant-speed (variable-pitch) propellers. The blades of
3618-476: The propeller through a gearbox. The 501-M62B also incorporated improvements proven by Allison's GMA 300 demonstrator program, which allowed for an airflow of 42 lb/s (1,100 kg/min). After DSTR testing was successful, the 501-M62B engine was further developed into the XT701 -AD-700 engine for use on the HLH. The 8,079 shp (6,025 kW) XT701 passed the tests required to enter ground and flight testing on
3685-485: The propeller. This allows for propeller strike or similar damage to occur without damaging the gas generator and allowing for only the power section (turbine and gearbox) to be removed and replaced in such an event, and also allows for less stress on the start during engine ground starts. Whereas a fixed shaft has the gearbox and gas generator connected, such as on the Honeywell TPE331 . The propeller itself
3752-399: The propulsion airflow is less clearly defined for propellers than for fans. The propeller is coupled to the turbine through a reduction gear that converts the high RPM /low torque output to low RPM/high torque. This can be of two primary designs, free-turbine and fixed. A free-turbine turboshaft found on the Pratt & Whitney Canada PT6 , where the gas generator is not connected to
3819-518: The required 3,750 shp (2,796 kW) for the YC-130A. Evolution of the T56 has been achieved through increases in pressure ratio and turbine temperature. The T56-A-14 installed on the P-3 Orion has a 4,591 shp (3,424 kW) rating with a pressure ratio of 9.25:1 while the T56-A-427 fitted to the E-2 Hawkeye has a 5,250 shp (3,915 kW) rating and a 12:1 pressure ratio. In addition,
3886-592: The same speed as small regional jet airliners but burn two-thirds of the fuel per passenger. Compared to piston engines, their greater power-to-weight ratio (which allows for shorter takeoffs) and reliability can offset their higher initial cost, maintenance and fuel consumption. As jet fuel can be easier to obtain than avgas in remote areas, turboprop-powered aircraft like the Cessna Caravan and Quest Kodiak are used as bush airplanes . Turboprop engines are generally used on small subsonic aircraft, but
3953-410: The way down to zero pitch, producing very little to zero-thrust and is typically accessed by moving the power lever to a beta for taxi range. Beta plus power is a reverse range and produces negative thrust, often used for landing on short runways where the aircraft would need to rapidly slow down, as well as backing operations and is accessed by moving the power lever below the beta for taxi range. Due to
4020-556: Was also approved in 2015 for engine retrofits on the U.S. Air Force's legacy C-130 aircraft that were currently in service with T56 Series III engines. As part of the T56 Series 3.5 upgrade, parts from the T56 Series IV engine (such as the compressor seals) and the uncooled turbine blades from the AE 1107C turboshaft would be retrofit into existing T56 Series III casing installations. Propeller upgrades to eight-bladed NP2000 propellers from UTC Aerospace Systems have been applied to
4087-429: Was derived from the fixed single-shaft T56, which had a four-stage section in which the first two stages provided enough power to drive the compressor, and the other two stages offered enough power to drive the propeller shaft. For the double-shaft 501-M62B engine, it was split into a two-stage turbine driving the compressor, where the turbine stages had air-cooled blades and vanes, and a two-stage free power turbine driving
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#17327721595134154-514: Was destroyed in a bombing raid. In 1941, the engine was abandoned due to war, and the factory converted to conventional engine production. The first mention of turboprop engines in the general public press was in the February 1944 issue of the British aviation publication Flight , which included a detailed cutaway drawing of what a possible future turboprop engine could look like. The drawing
4221-587: Was expected to be developed into the powerplant for the United States Navy 's JVX experimental tiltrotor aircraft program (which would eventually become the Bell Boeing V-22 Osprey ). After this engine, which DDA called the Model 580, lost the competition to Pratt & Whitney and General Electric in 1983, Allison was separated from Detroit Diesel as a separate division within General Motors , and Allison's new management decided to pursue
4288-589: Was operated by the U.S. Navy for a short time. The first American turboprop engine was the General Electric XT31 , first used in the experimental Consolidated Vultee XP-81 . The XP-81 first flew in December 1945, the first aircraft to use a combination of turboprop and turbojet power. The technology of Allison's earlier T38 design evolved into the Allison T56 , used to power the Lockheed Electra airliner, its military maritime patrol derivative
4355-647: Was produced and tested at the Ganz Works in Budapest between 1937 and 1941. It was of axial-flow design with 15 compressor and 7 turbine stages, annular combustion chamber. First run in 1940, combustion problems limited its output to 400 bhp. Two Jendrassik Cs-1s were the engines for the world's first turboprop aircraft – the Varga RMI-1 X/H . This was a Hungarian fighter-bomber of WWII which had one model completed, but before its first flight it
4422-603: Was the first turboprop aircraft of any kind to go into production and sold in large numbers. It was also the first four-engined turboprop. Its first flight was on 16 July 1948. The world's first single engined turboprop aircraft was the Armstrong Siddeley Mamba -powered Boulton Paul Balliol , which first flew on 24 March 1948. The Soviet Union built on German World War II turboprop preliminary design work by Junkers Motorenwerke, while BMW, Heinkel-Hirth and Daimler-Benz also worked on projected designs. While
4489-488: Was very close to what the future Rolls-Royce Trent would look like. The first British turboprop engine was the Rolls-Royce RB.50 Trent , a converted Derwent II fitted with reduction gear and a Rotol 7 ft 11 in (2.41 m) five-bladed propeller. Two Trents were fitted to Gloster Meteor EE227 — the sole "Trent-Meteor" — which thus became the world's first turboprop-powered aircraft to fly, albeit as
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