75-455: The Rolls-Royce RB.108 was a British jet engine designed in the mid-1950s by Rolls-Royce specifically for use as a VTOL lift engine . It was also used to provide horizontal thrust in the Short SC.1 . The RB.108 was the first direct-lift turbojet produced by Rolls-Royce. It originated from a VTOL concept in which Alan A. Griffith proposed using a small number of specialised lift engines in
150-399: A convergent-divergent nozzle is needed on high-speed aircraft. The engine thrust is highest if the static pressure of the gas reaches the ambient value as it leaves the nozzle. This only happens if the nozzle exit area is the correct value for the nozzle pressure ratio (npr). Since the npr changes with engine thrust setting and flight speed this is seldom the case. Also at supersonic speeds
225-675: A rotating air compressor powered by a turbine , with the leftover power providing thrust through the propelling nozzle —this process is known as the Brayton thermodynamic cycle . Jet aircraft use such engines for long-distance travel. Early jet aircraft used turbojet engines that were relatively inefficient for subsonic flight. Most modern subsonic jet aircraft use more complex high-bypass turbofan engines . They give higher speed and greater fuel efficiency than piston and propeller aeroengines over long distances. A few air-breathing engines made for high-speed applications (ramjets and scramjets ) use
300-644: A VTOL aircraft, separate from the engines which provided forward propulsion. Its power output (thrust) was not high enough for use as a practical engine in a production aircraft and was used only for research into VTOL. It was constructed from conventional materials. (The next lift engine, the RB.162 , would have a compressor built mainly from glass-fibre composite and have a higher T/W ratio.) The RB.108 bearings and oil system were designed to operate with an engine attitude envelope which covered engine and aircraft tilting while transitioning between hovering and forward flight. When
375-399: A central gas turbine which drives open-air contra-rotating propellers . Unlike turboprop engines, in which the propeller and the engine are considered two separate products, the propfan’s gas generator and its unshrouded propeller module are heavily integrated and are considered to be a single product. Additionally, the propfan’s short, heavily twisted variable pitch blades closely remember
450-408: A compressor ( axial , centrifugal , or both), mixing fuel with the compressed air, burning the mixture in the combustor , and then passing the hot, high pressure air through a turbine and a nozzle . The compressor is powered by the turbine, which extracts energy from the expanding gas passing through it. The engine converts internal energy in the fuel to increased momentum of the gas flowing through
525-623: A fifth engine was installed in the SC.1 to provide forward thrust it had to be mounted at about 45 degrees to remain within the envelope. The exhaust was directed horizontally with a curved jetpipe. The RB.108 was used in the Short SC.1 , which used four for lift with an additional one mounted at an angle at the rear for propulsion, and the Dassault Balzac V , which used eight vertically mounted RB.108s for lift. The Vereinigte Flugtechnische Werke (VFW) SG 1262 used five RB.108s, three mounted in tandem on
600-735: A half hours (330 minutes) with one engine shut down. The aircraft, with GE90-115B engines, flew from Seattle to Taiwan as part of the ETOPS certification program. On November 10, 2005, the GE90 entered the Guinness World Records for a second time. The GE90-110B1 powered a 777-200LR during the world's longest flight by a commercial airliner, though there were no fare-paying passengers on the flight, only journalists and invited guests. The 777-200LR flew 13,423 mi (21,602 km) in 22 hours, 22 minutes, flying from Hong Kong to London "the long way": over
675-462: A higher priority than fuel efficiency, fans tend to be smaller or absent. Because of these distinctions, turbofan engine designs are often categorized as low-bypass or high-bypass , depending upon the amount of air which bypasses the core of the engine. Low-bypass turbofans have a bypass ratio of around 2:1 or less. A propfan engine is a type of airbreathing jet engine which combines aspects of turboprop and turbofan . It’s design consists of
750-406: A jet of water. The mechanical arrangement may be a ducted propeller with nozzle, or a centrifugal compressor and nozzle. The pump-jet must be driven by a separate engine such as a Diesel or gas turbine . All jet engines are reaction engines that generate thrust by emitting a jet of fluid rearwards at relatively high speed. The forces on the inside of the engine needed to create this jet give
825-426: A large number of different types of jet engines, all of which achieve forward thrust from the principle of jet propulsion . Commonly aircraft are propelled by airbreathing jet engines. Most airbreathing jet engines that are in use are turbofan jet engines, which give good efficiency at speeds just below the speed of sound. A turbojet engine is a gas turbine engine that works by compressing air with an inlet and
SECTION 10
#1732905972004900-544: A one-hour, triple-red-line engine stress test using a GE90-115B development engine at GE's outdoor test complex near Peebles, Ohio . It eclipsed the engine's previous Guinness world record of 122,965 lbf (546.98 kN). On November 10, 2017, its successor, the GE9X , reached a higher record thrust of 134,300 lbf (597 kN) in Peebles. The initial GE90 fan shaft design loads were greatly increased for operational torque and
975-728: A powerplant for the world's first jet- fighter aircraft , the Messerschmitt Me 262 (and later the world's first jet- bomber aircraft, the Arado Ar 234 ). A variety of reasons conspired to delay the engine's availability, causing the fighter to arrive too late to improve Germany's position in World War II , however this was the first jet engine to be used in service. Meanwhile, in Britain the Gloster E28/39 had its maiden flight on 15 May 1941 and
1050-501: A result, the GE90 engine can only be air-freighted using an outsize cargo aircraft such as the Antonov An-124 , which restricts shipping options if, due to an emergency diversion, a 777 were stranded needing an engine change. If the fan and fan case are removed the engine may be shipped using a 747 Freighter . The -94B for the -200ER was retrofitted with some of the first FAA-approved 3D-printed components. In 2011, its list price
1125-530: A strong thrust on the engine which pushes the craft forwards. Jet engines make their jet from propellant stored in tanks that are attached to the engine (as in a 'rocket') as well as in duct engines (those commonly used on aircraft) by ingesting an external fluid (very typically air) and expelling it at higher speed. A propelling nozzle produces a high velocity exhaust jet . Propelling nozzles turn internal and pressure energy into high velocity kinetic energy. The total pressure and temperature don't change through
1200-421: A supersonic afterburning engine or 2200 K with afterburner lit. The pressure entering the nozzle may vary from 1.5 times the pressure outside the nozzle, for a single stage fan, to 30 times for the fastest manned aircraft at Mach 3+. Convergent nozzles are only able to accelerate the gas up to local sonic (Mach 1) conditions. To reach high flight speeds, even greater exhaust velocities are required, and so
1275-697: A then-industry record pressure ratio of 23:1 and is driven by a 2-stage, air-cooled, HP turbine. A 3-stage low-pressure compressor, situated directly behind the fan, supercharges the core. The fan/LPC is driven by a 6-stage low-pressure turbine. The higher-thrust variants, GE90-110B1 and -115B, have a different architecture from that of the earlier GE90 versions. General Electric incorporated an advanced larger diameter fan made from composite materials which enhanced thrust at low flight speeds. However, GE also needed to increase core power to improve net thrust at high flight speeds. Consequently, GE elected to increase core capacity, which they achieved by removing one stage from
1350-461: A two-stage axial compressor feeding a single-sided centrifugal compressor . Practical axial compressors were made possible by ideas from A.A.Griffith in a seminal paper in 1926 ("An Aerodynamic Theory of Turbine Design"). Whittle would later concentrate on the simpler centrifugal compressor only. Whittle was unable to interest the government in his invention, and development continued at a slow pace. In Spain, pilot and engineer Virgilio Leret Ruiz
1425-618: Is a family of high-bypass turbofan aircraft engines built by GE Aerospace for the Boeing 777 , with thrust ratings from 81,000 to 115,000 pounds-force (360 to 510 kilonewtons ). It entered service with British Airways in November 1995. It is one of three options for the 777-200, -200ER, and -300 versions, and the exclusive engine of the -200LR, -300ER, and 777F. It was the largest jet engine , until being surpassed in January 2020 by its successor,
1500-444: Is a twin-spool engine, allowing only two different speeds for the turbines. Ram compression jet engines are airbreathing engines similar to gas turbine engines in so far as they both use the Brayton cycle . Gas turbine and ram compression engines differ, however, in how they compress the incoming airflow. Whereas gas turbine engines use axial or centrifugal compressors to compress incoming air, ram engines rely only on air compressed in
1575-493: Is a type of reaction engine , discharging a fast-moving jet of heated gas (usually air) that generates thrust by jet propulsion . While this broad definition may include rocket , water jet , and hybrid propulsion, the term jet engine typically refers to an internal combustion air-breathing jet engine such as a turbojet , turbofan , ramjet , pulse jet , or scramjet . In general, jet engines are internal combustion engines . Air-breathing jet engines typically feature
SECTION 20
#17329059720041650-500: Is documented in the story of Ottoman soldier Lagâri Hasan Çelebi , who reportedly achieved flight using a cone-shaped rocket in 1633. The earliest attempts at airbreathing jet engines were hybrid designs in which an external power source first compressed air, which was then mixed with fuel and burned for jet thrust. The Italian Caproni Campini N.1 , and the Japanese Tsu-11 engine intended to power Ohka kamikaze planes towards
1725-400: Is the propellant flow in kg/s, A e {\displaystyle A_{e}} is the cross-sectional area at the exit of the exhaust nozzle, and p {\displaystyle p} is the atmospheric pressure. Combined-cycle engines simultaneously use two or more different principles of jet propulsion. A water jet, or pump-jet, is a marine propulsion system that uses
1800-566: Is used for launching satellites, space exploration and crewed access, and permitted landing on the Moon in 1969. Rocket engines are used for high altitude flights, or anywhere where very high accelerations are needed since rocket engines themselves have a very high thrust-to-weight ratio . However, the high exhaust speed and the heavier, oxidizer-rich propellant results in far more propellant use than turbofans. Even so, at extremely high speeds they become energy-efficient. An approximate equation for
1875-525: The 1979 oil crisis . NASA gave GE a grant in February 1984 to continue its research, eventually building the experimental GE36 . One of the major innovations for the engine were its carbon fiber composite fan blades, which were both lighter and stronger than traditional materials. However, the UDF was less reliable than the turbofans of the era, lower fuel costs made the cost of developing the engine less attractive, and
1950-867: The Gloster Meteor finally entered service with the RAF in July 1944. These were powered by turbojet engines from Power Jets Ltd., set up by Frank Whittle. The first two operational turbojet aircraft, the Messerschmitt Me 262 and then the Gloster Meteor entered service within three months of each other in 1944; the Me 262 in April and the Gloster Meteor in July. The Meteor only saw around 15 aircraft enter World War II action, while up to 1400 Me 262 were produced, with 300 entering combat, delivering
2025-500: The aeolipile , a device described by Hero of Alexandria in 1st-century Egypt . This device directed steam power through two nozzles to cause a sphere to spin rapidly on its axis. It was seen as a curiosity. Meanwhile, practical applications of the turbine can be seen in the water wheel and the windmill . Historians have further traced the theoretical origin of the principles of jet engines to traditional Chinese firework and rocket propulsion systems. Such devices' use for flight
2100-655: The gasoline -fuelled HeS 3 of 5 kN (1,100 lbf), which was fitted to Heinkel's simple and compact He 178 airframe and flown by Erich Warsitz in the early morning of August 27, 1939, from Rostock -Marienehe aerodrome , an impressively short time for development. The He 178 was the world's first jet plane. Heinkel applied for a US patent covering the Aircraft Power Plant by Hans Joachim Pabst von Ohain on May 31, 1939; patent number US2256198, with M Hahn referenced as inventor. Von Ohain's design, an axial-flow engine, as opposed to Whittle's centrifugal flow engine,
2175-402: The ram effect of the vehicle's speed instead of a mechanical compressor. The thrust of a typical jetliner engine went from 5,000 lbf (22 kN) ( de Havilland Ghost turbojet) in the 1950s to 115,000 lbf (510 kN) ( General Electric GE90 turbofan) in the 1990s, and their reliability went from 40 in-flight shutdowns per 100,000 engine flight hours to less than 1 per 100,000 in
2250-475: The -300ER over the A340-600. The 777-300ER was also seen as a 747-400 replacement amid rising fuel prices given its 20% fuel burn advantage. Until passed by its derivative, the GE9X , the GE90 series held the title of the largest engines in aviation history. The fan diameter of the original series being 123 in (310 cm), and the largest variant GE90-115B has a fan diameter of 128 in (330 cm). As
2325-508: The 110,000 lbf (490 kN) GE9X , which has a larger fan diameter by 6 inches (15 cm). However, the GE90-115B, the most recent variant of the GE90, is rated for a higher thrust (115,000 lbs) than the GE9X. In the early 1980s, GE began to develop an unducted fan (UDF) engine, which was thought to be a more fuel-efficient option to propel short-haul airliners, a compelling proposition after
Rolls-Royce RB.108 - Misplaced Pages Continue
2400-532: The 1950s, the jet engine was almost universal in combat aircraft, with the exception of cargo, liaison and other specialty types. By this point, some of the British designs were already cleared for civilian use, and had appeared on early models like the de Havilland Comet and Avro Canada Jetliner . By the 1960s, all large civilian aircraft were also jet powered, leaving the piston engine in low-cost niche roles such as cargo flights. The efficiency of turbojet engines
2475-405: The 30-inch (760 mm) greater diameter of the GE90. Having fewer fan blades reduces the engine weight and improves aerodynamic efficiency. With the stiff competition to equip the first generation 777 models (777-200, 777-200ER, no GE90 orders for the 777-300), GE tried to branch out and use the GE90 for other aircraft. Then-CEO Brian H. Rowe went so far as to offer to pay for the development of
2550-507: The 777 Classics) while the Rolls-Royce engine was the most popular. For Boeing's second-generation 777 long-range versions (later named 777-200LR, 777-300ER, and 777F), greater thrust was needed to meet the aircraft requirements. General Electric and Pratt & Whitney insisted on a winner-take-all contract due to the $ 500 million investment in engine modifications needed to meet the requirements. GE received sole engine supplier status for
2625-592: The 777, the PW4000 and Trent 800 , respectively. The major innovation of the GE90 was that it used 22 carbon fiber composite fan blades, technology first developed for the GE36. These blades provided double the strength at one-third the weight of traditional titanium fan blades. The 22 fan blades were a significant reduction from the 38 blades used in GE's prior large turbofan, the CF6 , despite
2700-548: The AD. All affected modules have been replaced. The GEnx engine, that has been developed for the Boeing 787 Dreamliner and 747-8 , is derived from a smaller core variant of the GE90, also featuring a fan with swept rotor blades. GE Aviation set up a cooperative venture with Pratt & Whitney, named Engine Alliance , under which the companies have developed an engine for the Airbus A380 , named GP7000, based on an 0.72 flow scale of
2775-512: The British embassy in Madrid a few years later by his wife, Carlota O'Neill , upon her release from prison. In 1935, Hans von Ohain started work on a similar design to Whittle's in Germany, both compressor and turbine being radial, on opposite sides of the same disc, initially unaware of Whittle's work. Von Ohain's first device was strictly experimental and could run only under external power, but he
2850-518: The GE90 for the Airbus A330 , but Airbus rebuffed the plan, instead choosing to focus on the four-engine A340 for the long-haul market. In the late 1990s, Boeing began developing the second-generation 777 long-range variants (777-200LR, 777-300ER, 777F). For these aircraft a more powerful engine in the thrust class of 100,000 lbf (440 kN) was required, leading to talks between Boeing and engine manufacturers. General Electric offered to develop
2925-525: The GE90 with the Rolls-Royce Trent 800 on their 777s. No 777-300s were ordered with the GE90, and ending up this combination was never certified by the FAA. In addition the GE90's increased thrust was not yet required by airlines and it was also the heaviest engine of the three available choices, making it the least popular option on these first generation 777s (777-200, 777-200ER, 777-300, also known collective as
3000-548: The GE90-110B/115B core. In February 2012, GE announced studies on a 10% more efficient derivative, dubbed the GE9X, to power the new Boeing 777-8X/9X aircraft. The LM9000 is an aeroderivative gas turbine available in two options; the LM9000 without water augmentation outputting 66 MW (89,000 hp) at a 42.4% efficiency before cogeneration , and the LM9000 with water augmentation outputting 75 MW (101,000 hp) at
3075-521: The GE90-115B engine, while Rolls-Royce proposed developing the Trent 8104 engine. In 1999, Boeing announced an agreement with General Electric, beating out rival proposals. Under the deal with General Electric, Boeing agreed to only offer GE90 engines on new 777 versions. The GE90-115B had its first run at the GE facility in Peebles , Ohio in November 2001. The GE90's 10-stage high-pressure compressor developed
Rolls-Royce RB.108 - Misplaced Pages Continue
3150-403: The GE90-115B have a length of 4 feet (1.2 meters) and a mass of less than 50 pounds (23 kilograms). As one of the three available engines for the all-new Boeing 777 large twinjet airliner, the GE90 was an all-new $ 2 billion design in contrast to the offerings from Pratt & Whitney and Rolls-Royce which were modifications of existing engines. The first General Electric-powered Boeing 777
3225-531: The Pacific, over the continental U.S., then over the Atlantic to London. On August 11, 2004, a GE90-85B powering a Boeing 777-200ER on British Airways flight 2024 suffered an engine failure on takeoff from George Bush Intercontinental Airport, Houston. The pilots noticed a noise and vibration on takeoff but continued the rotation. At 1500 ft AGL they noticed smoke and haze in the cockpit and cabin crew advised cabin
3300-526: The Pratt & Whitney J57 and J75 models. There is also a derivative of the P&;W JT8D low-bypass turbofan that creates up to 35,000 horsepower (HP) . Jet engines are also sometimes developed into, or share certain components such as engine cores, with turboshaft and turboprop engines, which are forms of gas turbine engines that are typically used to power helicopters and some propeller-driven aircraft. There are
3375-551: The centreline, with one RB.108 either side. The RB.108 was also the intended powerplant for several other VTOL aircraft designs, including one by Dornier . A similar lift jet was designed by Bristol Siddeley , the BS.59 , with a thrust of 8,000 lb the engine was intended for the projected Focke-Wulf Fw 260 . Data from Aircraft engines of the World 1964/65. Related development Related lists Jet engine A jet engine
3450-498: The company was worried the GE36 would cannibalize sales of the highly successful CFM56 engine it had co-developed with Snecma of France. The GE90 engine was launched in 1990 to provide a large turbofan engine for the Boeing 777 , a wide-body, long-range, twin-engine jet airliner. GE Aviation teamed with Snecma (France, 24%), IHI (Japan) and Avio (Italy) for the program. The GE90 would face stiff competition as Pratt & Whitney and Rolls-Royce would also offer engines for
3525-621: The divergent area is less than required to give complete internal expansion to ambient pressure as a trade-off with external body drag. Whitford gives the F-16 as an example. Other underexpanded examples were the XB-70 and SR-71. The nozzle size, together with the area of the turbine nozzles, determines the operating pressure of the compressor. This overview highlights where energy losses occur in complete jet aircraft powerplants or engine installations. General Electric GE90 The General Electric GE90
3600-510: The ducted fan blades of turbofan engines. Propfans are designed to offer the speed and performance of turbofan engines with fuel efficiency of turboprops. However, due to low fuel costs and high cabin noise, early propfan projects were abandoned. Very few aircraft have flown with propfans, with the Antonov An-70 being the first and only aircraft to fly while being powered solely by propfan engines. The term Advanced technology engine refers to
3675-405: The end of World War II were unsuccessful. Even before the start of World War II, engineers were beginning to realize that engines driving propellers were approaching limits due to issues related to propeller efficiency, which declined as blade tips approached the speed of sound . If aircraft performance were to increase beyond such a barrier, a different propulsion mechanism was necessary. This
3750-650: The engine, producing thrust. All the air entering the compressor is passed through the combustor, and turbine, unlike the turbofan engine described below. Turbofans differ from turbojets in that they have an additional fan at the front of the engine, which accelerates air in a duct bypassing the core gas turbine engine. Turbofans are the dominant engine type for medium and long-range airliners . Turbofans are usually more efficient than turbojets at subsonic speeds, but at high speeds their large frontal area generates more drag . Therefore, in supersonic flight, and in military and other aircraft where other considerations have
3825-468: The failures were caused by TGB radial gear cracking and separation. This through the combined effect of manufacturing process and operating stresses. Further inspections found two additional radial gears with cracks. This condition, if not corrected, could result in additional IFSDs of one or more engines, loss of thrust control, and damage to the airplane. The Airworthiness Directive requires compliance by taking remedial measures within five days of receipt of
SECTION 50
#17329059720043900-454: The fan blade-off condition. To accommodate the increase in fan-shaft torsional and bending stresses, a steel alloy, GE1014, not previously used in aircraft engines was required. A significantly longer fan shaft spline-coupling was required and maintaining the required high machining accuracy was challenging. In October 2003, a Boeing 777-300ER broke the ETOPS record by being able to fly five and
3975-463: The first ground attacks and air combat victories of jet planes. Following the end of the war the German jet aircraft and jet engines were extensively studied by the victorious allies and contributed to work on early Soviet and US jet fighters. The legacy of the axial-flow engine is seen in the fact that practically all jet engines on fixed-wing aircraft have had some inspiration from this design. By
4050-712: The form of rocket engines they power model rocketry , spaceflight , and military missiles . Jet engines have propelled high speed cars, particularly drag racers , with the all-time record held by a rocket car . A turbofan powered car, ThrustSSC , currently holds the land speed record . Jet engine designs are frequently modified for non-aircraft applications, as industrial gas turbines or marine powerplants . These are used in electrical power generation, for powering water, natural gas, or oil pumps, and providing propulsion for ships and locomotives. Industrial gas turbines can create up to 50,000 shaft horsepower. Many of these engines are derived from older military turbojets such as
4125-484: The higher-thrust engine variants for the 777-200LR, -300ER, and 777F. The improved version entered service with Air France in May 2004. The higher thrust GE90-110B1 and -115B engines, in combination with the second-generation 777 variants -200LR and -300ER, were primary reasons for 777 sales being greater than those of the rival A330/340 series. Using two engines produces a typical operating cost advantage of around 8–9% for
4200-490: The inlet or diffuser. A ram engine thus requires a substantial initial forward airspeed before it can function. Ramjets are considered the simplest type of air breathing jet engine because they have no moving parts in the engine proper, only in the accessories. Scramjets differ mainly in the fact that the air does not slow to subsonic speeds. Rather, they use supersonic combustion. They are efficient at even higher speed. Very few have been built or flown. The rocket engine uses
4275-458: The late 1990s. This, combined with greatly decreased fuel consumption, permitted routine transatlantic flight by twin-engined airliners by the turn of the century, where previously a similar journey would have required multiple fuel stops. The principle of the jet engine is not new; however, the technical advances necessary to make the idea work did not come to fruition until the 20th century. A rudimentary demonstration of jet power dates back to
4350-432: The malfunctioning right engine caught fire, leading to fire damage to the engine and the wing. The FAA issued an Airworthiness Directive (AD) on May 16, 2013, and sent it to owners and operators of General Electric GE90-110B1 and GE90-115B turbofan engines. This emergency AD was prompted by reports of two failures of transfer gearbox assemblies (TGBs) which resulted in in-flight shutdowns (IFSDs). Investigation revealed that
4425-433: 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
4500-394: The net thrust of a rocket engine is: Where F N {\displaystyle F_{N}} is the net thrust, I sp,vac {\displaystyle I_{\text{sp,vac}}} is the specific impulse , g 0 {\displaystyle g_{0}} is a standard gravity , m ˙ {\displaystyle {\dot {m}}}
4575-404: The nozzle but their static values drop as the gas speeds up. The velocity of the air entering the nozzle is low, about Mach 0.4, a prerequisite for minimizing pressure losses in the duct leading to the nozzle. The temperature entering the nozzle may be as low as sea level ambient for a fan nozzle in the cold air at cruise altitudes. It may be as high as the 1000 Kelvin exhaust gas temperature for
SECTION 60
#17329059720044650-456: The other three engines at idle, an attribute demonstrated during a flight test. According to the Guinness Book of Records , at 127,900 lbf (569 kN), the engine held the record for the highest thrust achieved by an aircraft engine (the maximum thrust for the engine in service is its rated thrust 115,300 lbf (513 kN)). This thrust record was reached inadvertently as part of
4725-496: The rear of the HP compressor and adding an additional stage to the LP compressor, which more than compensated for the reduction in HP compressor pressure ratio, resulting in a net increase in core mass flow . The higher-thrust GE90 variants are the first production engines to feature swept rotor blades. The nacelle has a maximum diameter of 166 in (4,200 mm). Each of the 22 fan blades on
4800-424: The same basic physical principles of thrust as a form of reaction engine , but is distinct from the jet engine in that it does not require atmospheric air to provide oxygen; the rocket carries all components of the reaction mass. However some definitions treat it as a form of jet propulsion . Because rockets do not breathe air, this allows them to operate at arbitrary altitudes and in space. This type of engine
4875-531: The state of the art in compressors. Alan Arnold Griffith published An Aerodynamic Theory of Turbine Design in 1926 leading to experimental work at the RAE . In 1928, RAF College Cranwell cadet Frank Whittle formally submitted his ideas for a turbojet to his superiors. In October 1929, he developed his ideas further. On 16 January 1930, in England, Whittle submitted his first patent (granted in 1932). The patent showed
4950-521: Was US$ 27.5 million, and it had an in-flight shutdown rate (IFSD) of one per million engine flight-hours. Until November 2015, it accumulated more than 8 million cycles and 50 million flight hours in 20 years. In July 2020, the fleet of 2,800 engines surpassed 100 million hours, powering over 1,200 aircraft for 70 operators with a dispatch reliability rate of 99.97%. A complete overhaul costs more than $ 12 million. The GE90-115B provided enough thrust to fly N747GE , GE's Boeing 747-100 flying testbed with
5025-600: Was able to demonstrate the basic concept. Ohain was then introduced to Ernst Heinkel , one of the larger aircraft industrialists of the day, who immediately saw the promise of the design. Heinkel had recently purchased the Hirth engine company, and Ohain and his master machinist Max Hahn were set up there as a new division of the Hirth company. They had their first HeS 1 centrifugal engine running by September 1937. Unlike Whittle's design, Ohain used hydrogen as fuel, supplied under external pressure. Their subsequent designs culminated in
5100-406: Was built in 1903 by Norwegian engineer Ægidius Elling . Such engines did not reach manufacture due to issues of safety, reliability, weight and, especially, sustained operation. The first patent for using a gas turbine to power an aircraft was filed in 1921 by Maxime Guillaume . His engine was an axial-flow turbojet, but was never constructed, as it would have required considerable advances over
5175-571: Was delivered to British Airways on November 12, 1995. The aircraft, with two GE90-77Bs, entered service five days later. Initial service was affected by gearbox bearing wear concerns, which caused the airline to temporarily withdraw its 777 fleet from transatlantic service in 1997. British Airways' aircraft returned to full service later that year. Problems with GE90 development and testing caused delays in Federal Aviation Administration certification. British Airways soon replaced
5250-571: Was eventually adopted by most manufacturers by the 1950s. Austrian Anselm Franz of Junkers ' engine division ( Junkers Motoren or "Jumo") introduced the axial-flow compressor in their jet engine. Jumo was assigned the next engine number in the RLM 109-0xx numbering sequence for gas turbine aircraft powerplants, "004", and the result was the Jumo 004 engine. After many lesser technical difficulties were solved, mass production of this engine started in 1944 as
5325-432: Was filling with smoke. They returned to the airport for an immediate emergency landing. Findings were a stage 2 turbine blade had separated at its shank damaging the trailing blades causing the vibration. The debris was contained in the engine casing. On May 28, 2012, an Air Canada 777-300ER taking off from Toronto en route to Tokyo suffered failure of a GE90-115B at 1,500 feet (460 m) and returned safely. Engine debris
5400-589: Was found on the ground. On September 8, 2015, a GE90-85B powering a Boeing 777-236ER on British Airways Flight 2276 suffered an uncontained failure during take-off roll at Las Vegas McCarran Airport, leading to a fire. NTSB and FAA investigations were begun to determine the cause; initial findings were reported in September 2015. On June 27, 2016, a GE90-115B powering a Boeing 777-300ER, on Singapore Airlines Flight 368, received an engine oil warning during flight and returned to Singapore Changi Airport . On landing
5475-574: Was granted a patent for a jet engine design in March 1935. Republican president Manuel Azaña arranged for initial construction at the Hispano-Suiza aircraft factory in Madrid in 1936, but Leret was executed months later by Francoist Moroccan troops after unsuccessfully defending his seaplane base on the first days of the Spanish Civil War . His plans, hidden from Francoists, were secretly given to
5550-427: Was still rather worse than piston engines, but by the 1970s, with the advent of high-bypass turbofan jet engines (an innovation not foreseen by the early commentators such as Edgar Buckingham , at high speeds and high altitudes that seemed absurd to them), fuel efficiency was about the same as the best piston and propeller engines. Jet engines power jet aircraft , cruise missiles and unmanned aerial vehicles . In
5625-409: Was the motivation behind the development of the gas turbine engine, the most common form of jet engine. The key to a practical jet engine was the gas turbine , extracting power from the engine itself to drive the compressor . The gas turbine was not a new idea: the patent for a stationary turbine was granted to John Barber in England in 1791. The first gas turbine to successfully run self-sustaining
#3996