A turboprop is a
turbine engine
A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directi ...
that drives an aircraft
propeller.
A turboprop consists of an
intake
An intake (also inlet) is an opening, structure or system through which a fluid is admitted to a space or machine as a consequence of a pressure differential between the outside and the inside. The pressure difference may be generated on the ins ...
,
reduction gearbox
An epicyclic gear train (also known as a planetary gearset) consists of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates the planet and sun gea ...
,
compressor,
combustor
A combustor is a component or area of a gas turbine, ramjet, or scramjet engine where combustion takes place. It is also known as a burner, combustion chamber or flame holder. In a gas turbine engine, the ''combustor'' or combustion chamber is f ...
,
turbine
A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating ...
, and a
propelling nozzle
A propelling nozzle is a nozzle that converts the internal energy of a working gas into propulsive force; it is the nozzle, which forms a jet, that separates a gas turbine, or gas generator, from a jet engine.
Propelling nozzles accelerate the av ...
. 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 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
The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, an ...
or
turbofan
The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the ''turbo'' portion refers to a gas turbine engine which achieves mechanic ...
, the engine's
exhaust gas
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an ...
es do not provide enough energy to create significant thrust, since almost all of the engine's power is used to drive the propeller.
Technological aspects
![Propulsive efficiency for different engine types and Mach numbers](https://upload.wikimedia.org/wikipedia/commons/8/87/Propulsive_efficiency_for_different_engine_types_and_Mach_numbers.png)
Exhaust thrust in a turboprop 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.
[Turboprop Engine]
''Glenn Research Center
NASA John H. Glenn Research Center at Lewis Field is a NASA center within the cities of Brook Park and Cleveland between Cleveland Hopkins International Airport and the Rocky River Reservation of Cleveland Metroparks, with a subsidiary facilit ...
(NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
)''[Turboprop Thrust]
''Glenn Research Center
NASA John H. Glenn Research Center at Lewis Field is a NASA center within the cities of Brook Park and Cleveland between Cleveland Hopkins International Airport and the Rocky River Reservation of Cleveland Metroparks, with a subsidiary facilit ...
(NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
)'' Consequently, the exhaust jet produces about 10% of the total thrust.
["The turbofan engine]
", page 7. SRM Institute of Science and Technology
SRM Institute of Science and Technology (SRMIST), formerly SRM University, is a private higher education institute deemed to be university, located in Kattankulathur, Chengalpattu (near Chennai), Tamil Nadu, India. Founded in 1985 as SRM Eng ...
, Department of aerospace engineering. A higher proportion of the thrust comes from the propeller at low speeds and less at higher speeds.
Turboprops have
bypass ratio
The bypass ratio (BPR) of a turbofan engine is the ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core. A 10:1 bypass ratio, for example, means that 10 kg of air passes through the bypass duct for ev ...
s of 50-100,
[Ilan Kroo and Juan Alonso.]
Aircraft Design: Synthesis and Analysis, Propulsion Systems: Basic Concepts
" Stanford University School of Engineering, Department of Aeronautics and Astronautic
'' MIT turbines'', 2002
Thermodynamics and Propulsion
/ref> although the propulsion airflow is less clearly defined for propellers than for fans.
''Glenn Research Center
NASA John H. Glenn Research Center at Lewis Field is a NASA center within the cities of Brook Park and Cleveland between Cleveland Hopkins International Airport and the Rocky River Reservation of Cleveland Metroparks, with a subsidiary facilit ...
(NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
)''[Philip Walsh, Paul Fletcher.]
Gas Turbine Performance
, page 36. John Wiley & Sons, 15 April 2008. Quote: "It has better fuel consumption than a turbojet or turbofan, due to a high propulsive efficiency.., achieving thrust by a high mass flow of air from the propeller at low jet velocity. Above 0.6 Mach number the turboprop in turn becomes uncompetitive, due mainly to higher weight and frontal area."
The propeller is coupled to the turbine through a reduction gear
A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage.
Gear teeth are designed to ensure the pitch circles of engaging gears roll on each other without slipping, providing a smooth transmission ...
that converts the high RPM
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
/low torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
output to low RPM/high torque. The propeller itself is normally a constant-speed (variable pitch) propeller type similar to that used with larger aircraft reciprocating engine
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common fea ...
s, except that the propeller-control requirements are very different.
To make the engine more compact, reverse airflow can be used. On a reverse-flow turboprop engine, 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
The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the ''turbo'' portion refers to a gas turbine engine which achieves mechanic ...
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 a large amount of air by a small degree than a small amount of air by a large degree,Paul Bevilaqua
Paul Bevilaqua is an aeronautics engineer at Lockheed Martin in California. In 1990, he invented the lift fan for the Joint Strike Fighter F-35B along with fellow Skunk Works engineer Paul Shumpert.
In 2005, Bevilaqua was elected as a member ...
The shaft driven Lift Fan propulsion system for the Joint Strike Fighter
page 3. Presented 1 May 1997. DTIC.MIL Word document, 5.5 MB. Retrieved 25 February 2012.[ Bensen, Igor.]
How they fly – Bensen explains all
''Gyrocopters UK''. Retrieved 10 April 2014. a low disc loading
In fluid dynamics, disk loading or disc loading is the average pressure change across an actuator disk, such as an airscrew. Airscrews with a relatively low disk loading are typically called rotors, including helicopter main rotors and tail roto ...
(thrust per unit disc area) increases the aircraft's energy efficiency, and this reduces the fuel use.[Johnson, Wayne]
Helicopter theory
pp3+32, ''Courier Dover Publications'', 1980. Retrieved 25 February 2012. [Wieslaw Zenon Stepniewski, C. N. Keys]
Rotary-wing aerodynamics
p3, Courier Dover Publications, 1979. Retrieved 25 February 2012.
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 the propeller that is converted to propeller thrust falls dramatically. For this reason turboprop engines are not used on aircraft[ that fly faster than 0.6–0.7 Mach.][ However, ]propfan
A propfan, also called an open rotor engine, or unducted fan (as opposed to a ducted fan), is a type of aircraft engine related in concept to both the turboprop and turbofan, but distinct from both. The design is intended to offer the speed a ...
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 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 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.
History
Alan Arnold Griffith
Alan Arnold Griffith (13 June 1893 – 13 October 1963), son of Victorian science fiction writer George Griffith, was an English engineer. Among many other contributions he is best known for his work on stress and fracture in metals that is n ...
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
Air Commodore Sir Frank Whittle, (1 June 1907 – 8 August 1996) was an English engineer, inventor and Royal Air Force (RAF) air officer. He is credited with inventing the turbojet engine. A patent was submitted by Maxime Guillaume in 1921 fo ...
began work on centrifugal compressor-based designs that would use all the gas power produced by the engine for jet thrust.
The world's first turboprop was designed by the Hungarian mechanical engineer
Mechanical may refer to:
Machine
* Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement
* Mechanical calculator, a device used to perform the basic operations of ...
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, was produced and tested at the Ganz Works
The Ganz Works or Ganz ( or , ''Ganz companies'', formerly ''Ganz and Partner Iron Mill and Machine Factory'') was a group of companies operating between 1845 and 1949 in Budapest, Hungary. It was named after Ábrahám Ganz, the founder and the ...
in Budapest
Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population ...
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. In 1941, the engine was abandoned due to war, and the factory was turned over 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
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...
'', which included a detailed cutaway drawing of what a possible future turboprop engine could look like. The drawing was very close to what the future Rolls-Royce Trent would look like. The first British turboprop engine was the Rolls-Royce
Rolls-Royce (always hyphenated) may refer to:
* Rolls-Royce Limited, a British manufacturer of cars and later aero engines, founded in 1906, now defunct
Automobiles
* Rolls-Royce Motor Cars, the current car manufacturing company incorporated in ...
RB.50 Trent, a converted Derwent II fitted with reduction gear and a Rotol
Dowty Propellers is a British engineering company based in Brockworth, Gloucestershire that specialises in the manufacture, repair and overhaul of propellers and propeller components for customers around the world. It is owned by General Elect ...
five-bladed propeller. Two Trents were fitted to Gloster Meteor
The Gloster Meteor was the first British jet fighter and the Allies of World War II, Allies' only jet aircraft to engage in combat operations during the Second World War. The Meteor's development was heavily reliant on its ground-breaking turb ...
''EE227'' — the sole "Trent-Meteor" — which thus became the world's first turboprop-powered aircraft, albeit 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 Rolls-Royce RB.39 Clyde was Rolls-Royce's first purpose-designed turboprop engine and the first turboprop engine to pass its civil and military type-tests.
As with subsequent Rolls-Royce gas turbines, it was named after a river, the Rive ...
, the first turboprop engine to receive a type certificate
A type certificate signifies the airworthiness of a particular category of aircraft, according to its manufacturing design (''type design''). It confirms that the aircraft of a new type intended for serial production, is in compliance with applica ...
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
The Vickers Viscount is a British medium-range turboprop airliner first flown in 1948 by Vickers-Armstrongs. A design requirement from the Brabazon Committee, it entered service in 1953 and was the first turboprop-powered airliner.
The Vi ...
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
Hirth Engines GmbH is an engine manufacturer based in Benningen, Germany. It is currently a part of the UMS Aero Group. Hirth began manufacturing aero engines in the 1920s, was taken over by Heinkel in WWII to develop the Heinkel-Hirth jet e ...
and Daimler-Benz
The Mercedes-Benz Group AG (previously named Daimler-Benz, DaimlerChrysler and Daimler) is a German multinational automotive corporation headquartered in Stuttgart, Baden-Württemberg, Germany. It is one of the world's leading car manufactur ...
also worked on projected designs. While 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
The Kuznetsov NK-12 is a Soviet turboprop engine of the 1950s, designed by the Kuznetsov design bureau. The NK-12 drives two large four-bladed contra-rotating propellers, diameter (NK-12MA), and diameter (NK-12MV). It is the most powerful ...
turboprops, mated to eight contra-rotating propellers
Aircraft equipped with contra-rotating propellers, also referred to as CRP, coaxial contra-rotating propellers, or high-speed propellers, apply the maximum power of usually a single piston or turboprop engine to drive a pair of coaxial propell ...
(two per nacelle) with supersonic tip speeds to achieve maximum cruise speeds in excess of 575 mph, faster than many of 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 throughout the end of the 20th century. The USA used turboprop engines with contra-rotating propellers, such as the Allison T40
Allison may refer to:
People
* Allison (given name)
* Allison (surname) (includes a list of people with this name)
* Eugene Allison Smith (1922-1980), American politician and farmer
Companies
* Allison Engine Company, American aircraft engine ...
, on some experimental aircraft during the 1950s. The T40-powered Convair R3Y Tradewind flying-boat was operated by the U.S. Navy for a short time.
The first American turboprop engine was the General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable en ...
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
The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, an ...
power. The technology of Allison's earlier T38 design evolved into the Allison T56
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 tran ...
, used to power the Lockheed Electra airliner, its military maritime patrol derivative the P-3 Orion, and the C-130 Hercules military transport aircraft.
The first turbine-powered, shaft-driven helicopter was the Kaman K-225
The Kaman K-225 is an American experimental helicopter developed by Kaman Aircraft. One example was modified to become the world's first gas turbine-powered helicopter.
Design and development
The K-125 was Charles Kaman's first helicopter, whi ...
, a development of Charles Kaman's K-125 synchropter, which used a Boeing T50
The Boeing T50 (company designation Model 502) was a small turboshaft engine produced by Boeing. Based on Boeing's earlier Model 500 gas generator, the T50's main application was in the QH-50 DASH helicopter drone of the 1950s. An up-rated versi ...
turboshaft
A turboshaft engine is a form of gas turbine that is optimized to produce shaftpower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the exhaust ...
engine to power it on 11 December 1951.
Usage
In contrast to turbofan
The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the ''turbo'' portion refers to a gas turbine engine which achieves mechanic ...
s, 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 the same speed as small regional jet
A regional jet (RJ) is a jet-powered regional airliner with fewer than 100 seats. The first one was the Sud-Aviation Caravelle in 1959, followed by the widespread Yakovlev Yak-40, Fokker F-28, and BAe 146. The 1990s saw the emergence of ...
airliners but burn two-thirds of the fuel per passenger. However, compared to a turbojet
The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, an ...
(which can fly at high altitude for enhanced speed and fuel efficiency) a propeller aircraft has a lower ceiling.
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
The Cessna 208 Caravan is a utility aircraft produced by Cessna.
The project was commenced on November 20, 1981, and the prototype first flew on December 9, 1982.
The production model was certified by the FAA in October 1984 and its Cargoma ...
and Quest Kodiak
The Daher Kodiak (formerly Quest Kodiak) is an American utility aircraft designed by and originally manufactured by Quest Aircraft. Manufacturing was taken over by Daher in 2019 after its purchase of Quest Aircraft. The high-wing, unpressuri ...
are used as bush airplanes.
Turboprop engines are generally used on small subsonic aircraft, but the Tupolev Tu-114
The Tupolev Tu-114 Rossiya ( ru , link=no, Tyполев Тy-114 Poccия; NATO reporting name Cleat) was a turboprop-powered long-range airliner designed by the Tupolev design bureau and built in the Soviet Union from May 1955. The aircraft w ...
can reach 470 kn (870 km/h, 541 mph). Large military aircraft
A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat:
* Combat aircraft are designed to destroy enemy equi ...
, like the Tupolev Tu-95, and civil aircraft
Civil aviation is one of two major categories of flying, representing all non-military and non-state aviation, both private and commercial. Most of the countries in the world are members of the International Civil Aviation Organization and work ...
, such as the Lockheed L-188 Electra
The Lockheed L-188 Electra is an American turboprop airliner built by Lockheed. First flown in 1957, it was the first large turboprop airliner built in the United States. Initial sales were good, but after two fatal crashes that led to expensiv ...
, were also turboprop powered. The Airbus A400M is powered by four Europrop TP400
The Europrop International TP400-D6 is an 11,000 shp (8,200 kW) powerplant, developed and produced by Europrop International for the Airbus A400M Atlas military transport aircraft. The TP400 is the most powerful turboprop in service u ...
engines, which are the second most powerful turboprop engines ever produced, after the Kuznetsov NK-12
The Kuznetsov NK-12 is a Soviet turboprop engine of the 1950s, designed by the Kuznetsov design bureau. The NK-12 drives two large four-bladed contra-rotating propellers, diameter (NK-12MA), and diameter (NK-12MV). It is the most powerful ...
.
In 2017, the most widespread turboprop airliners in service were the ATR 42/ 72 (950 aircraft), Bombardier Q400 (506), De Havilland Canada Dash 8
The De Havilland Canada DHC-8, commonly known as the Dash 8, is a series of turboprop-powered regional airliners, introduced by de Havilland Canada (DHC) in 1984. DHC was later bought by Boeing in 1988, then by Bombardier in 1992; then by ...
-100/200/300 (374), Beechcraft 1900 (328), de Havilland Canada DHC-6 Twin Otter (270), Saab 340
The Saab 340 is a Swedish twin-engine turboprop aircraft designed and initially produced by Saab AB and Fairchild Aircraft. It is designed to seat 30-36 passengers and, as of July 2018, there were 240 operational aircraft used by 34 different o ...
(225). Less widespread and older airliners include the BAe Jetstream 31, Embraer EMB 120 Brasilia
The Embraer EMB 120 Brasilia is a twin-turboprop 30-passenger commuter airliner designed and manufactured by the Brazilian aircraft manufacturer Embraer.
The EMB 120 began development during 1974. While initially conceived as a modular series of ...
, Fairchild Swearingen Metroliner
The Fairchild Swearingen Metroliner (previously the Swearingen Metro and later Fairchild Aerospace Metro) is a 19-seat, pressurized, twin-turboprop airliner first produced by Swearingen Aircraft and later by Fairchild Aircraft at a plant in San ...
, Dornier 328
The Dornier 328 is a turboprop-powered commuter airliner. Initially produced by Dornier Luftfahrt GmbH, the firm was acquired in 1996 by Fairchild Aircraft. The resulting firm, named Fairchild-Dornier, manufactured the 328 family in Oberpfaffen ...
, Saab 2000
The Saab 2000 is a twin-engined high-speed turboprop airliner built by Swedish aircraft manufacturer Saab. It is designed to carry 50–58 passengers and cruise at a speed of . Production took place in Linköping in southern Sweden. The Saab ...
, Xian MA60
The Xian MA60 (新舟60, ''Xīnzhōu liùshí'', "Modern Ark 60") is a turboprop-powered airliner produced by China's Xi'an Aircraft Industrial Corporation under the Aviation Industry Corporation of China (AVIC). The MA60 is a stretched versio ...
, MA600 and MA700, Fokker 27
The Fokker F27 Friendship is a turboprop airliner developed and manufactured by the Dutch aircraft manufacturer Fokker. It is the most numerous post-war aircraft manufactured in the Netherlands; the F27 was also one of the most successful Euro ...
and 50.
Turboprop business aircraft include the Piper Meridian, Socata TBM
The SOCATA TBM (now Daher TBM) is a family of high-performance single-engine turboprop business and utility light aircraft manufactured by Daher. It was originally collaboratively developed between the American Mooney Airplane Company and F ...
, Pilatus PC-12, Piaggio P.180 Avanti
The Piaggio P.180 Avanti is an Italian executive transport aircraft with twin turboprop engines mounted in pusher configuration. It seats up to nine people in a pressurized cabin and may be flown by one or two pilots. The design is of three-su ...
, Beechcraft King Air and Super King Air
The Beechcraft Super King Air family is part of a line of twin-turboprop aircraft produced by Beechcraft. The Model 200 and Model 300 series were originally marketing, marketed as the "Super King Air" family; the "Super" designation was dropp ...
. In April 2017, there were 14,311 business turboprops in the worldwide fleet.
Reliability
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
An agricultural aircraft is an aircraft that has been built or converted for agricultural use – usually aerial application of pesticides (crop dusting) or fertilizer (aerial topdressing); in these roles they are referred to as "crop duster ...
and five accidents involved aerial work: four in agriculture and one in an air ambulance
Air medical services is a comprehensive term covering the use of air transportation, aeroplane or helicopter, to move patients to and from healthcare facilities and accident scenes. Personnel provide comprehensive prehospital and emergency and cri ...
.
Current engines
See also
* Jet engine
* Jetboat
A jetboat is a boat propelled by a jet of water ejected from the back of the craft. Unlike a powerboat or motorboat that uses an external propeller in the water below or behind the boat, a jetboat draws the water from under the boat through ...
* Scimitar propeller
A scimitar propeller is a type of propeller that has curved blades with increasing sweep along the leading edge. Their name is derived from their visual similarity to the curved blades of scimitars. In the early 1900s, as established by the Fr ...
* Supercharger
* Tiltrotor
A tiltrotor is an aircraft which generates lift and propulsion by way of one or more powered rotors (sometimes called ''proprotors'') mounted on rotating shafts or nacelles usually at the ends of a fixed wing. Almost all tiltrotors use a trans ...
* Turbocharger
In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...
References
Bibliography
*Green, W. and Cross, R.''The Jet Aircraft of the World'' (1955). London: MacDonald
*
*
* James, D.N. ''Gloster Aircraft since 1917'' (1971). London: Putnam & Co.
Further reading
*
External links
Jet Turbine Planes
by LtCol Silsbee USAAF, Popular Science, December 1945, first article on turboprops printed
* Wikibooks: Jet propulsion
"Development of the Turboprop"
a 1950 ''Flight'' article on UK and US turboprop engines
{{Authority control
Gas turbines
Aircraft engines
Jet engines