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35-765: GE evolved the F404 into the F412-GE-400 non-afterburning turbofan for the McDonnell Douglas A-12 Avenger II . After the cancellation of the A-12 in 1991, the research was directed toward an engine for the F/A-18E/F Super Hornet . GE successfully pitched the F414 as a low-risk derivative of the F404, rather than a riskier new engine. The F414 engine was originally envisioned as not using any materials or processes not used in

70-509: A 20% increase in thrust or threefold increase in hot-section durability over the current F414. This version is called the Enhanced Performance Engine (EPE) and was partially funded through the federal Integrated High Performance Turbine Engine Technology (or IHPTET) program. Other possible F414 improvements include efforts to reduce engine noise by using either mechanical or fluidic chevrons and efforts to reduce emissions with

105-628: A final bid. The General Dynamics/McDonnell Douglas team was awarded a development contract and the ATA aircraft was designated A-12 . The first flight was initially planned for December 1990. The A-12 was named Avenger II in homage to the World War II -era Navy torpedo-bomber Grumman TBF Avenger . The Navy initially sought to buy 620 A-12s and Marines wanted 238. In addition, the Air Force briefly considered ordering some 400 of an A-12 derivative. The A-12

140-405: A new trapped vortex combustor. Chevrons would reduce engine noise by inducing mixing between the cooler, slower bypass air and the hotter, faster core exhaust air. Mechanical chevrons would come in the form of triangular cutouts (or extensions) at the end of the nozzle, resulting in a "sharktooth" pattern. Fluidic chevrons would operate by injecting differential air flows around the exhaust to achieve

175-461: A second low-pressure turbine stage made from ceramic matrix composites (CMC). The F414 represents the first successful use of a CMC in a rotating engine part. The tests proved CMCs are strong enough to endure the heat and rotational stress inside the turbine. The advantage CMC offers is a weight one third that of metal alloy and the ability to operate without cooling air, making the engine more aerodynamically efficient and fuel efficient. The new turbine

210-450: A simplistic look at the table below. SFC varies with throttle setting, altitude, climate. For jet engines, air flight speed is an important factor too. Air flight speed counteracts the jet's exhaust speed. (In an artificial and extreme case with the aircraft flying exactly at the exhaust speed, one can easily imagine why the jet's net thrust should be near zero.) Moreover, since work is force ( i.e ., thrust) times distance, mechanical power

245-521: A subsonic aircraft flying at 570 mph, which would be better than even modern engines; the Olympus 593 used in the Concorde was the world's most efficient jet engine. However, Concorde ultimately has a heavier airframe and, due to being supersonic, is less aerodynamically efficient, i.e., the lift to drag ratio is far lower. In general, the total fuel burn of a complete aircraft is of far more importance to

280-618: Is a more appropriate comparison for aircraft that travel at very different speeds. There also exists power-specific fuel consumption , which equals the thrust-specific fuel consumption divided by speed. It can have units of pounds per hour per horsepower. SFC is dependent on engine design, but differences in the SFC between different engines using the same underlying technology tend to be quite small. Increasing overall pressure ratio on jet engines tends to decrease SFC. In practical applications, other factors are usually highly significant in determining

315-424: Is designed to have better foreign object damage resistance, and a reduced fuel burn rate. The EDE program continued with the testing of an advanced two stage blade-disk or " blisk " fan. The first advanced fan was produced using traditional methods, but future blisk fans will be made using translational friction welding with the goal of reducing manufacturing costs. GE touts that this latest variant yields either

350-461: Is force times speed. Thus, although the nominal SFC is a useful measure of fuel efficiency, it should be divided by speed when comparing engines at different speeds. For example, Concorde cruised at 1354 mph, or 7.15 million feet per hour, with its engines giving an SFC of 1.195 lb/(lbf·h) (see below); this means the engines transferred 5.98 million foot pounds per pound of fuel (17.9 MJ/kg), equivalent to an SFC of 0.50 lb/(lbf·h) for

385-405: Is not yet ready for a production aircraft, however, as further design changes are needed to make it more robust. As of 2023, over 1,600 F414 engines have been delivered. Data from GE Aviation, Deagal.com, and MTU Aero Engines Related development Comparable engines Related lists McDonnell Douglas A-12 Avenger II The General Dynamics/McDonnell Douglas A-12 Avenger II

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420-422: Is the fuel efficiency of an engine design with respect to thrust output. TSFC may also be thought of as fuel consumption (grams/second) per unit of thrust (newtons, or N), hence thrust-specific . This figure is inversely proportional to specific impulse , which is the amount of thrust produced per unit fuel consumed. TSFC or SFC for thrust engines (e.g. turbojets , turbofans , ramjets , rockets , etc.)

455-488: Is the mass of fuel needed to provide the net thrust for a given period e.g. lb/(h·lbf) (pounds of fuel per hour-pound of thrust) or g/(s·kN) (grams of fuel per second-kilonewton). Mass of fuel is used, rather than volume (gallons or litres) for the fuel measure, since it is independent of temperature. Specific fuel consumption of air-breathing jet engines at their maximum efficiency is more or less proportional to exhaust speed. The fuel consumption per mile or per kilometre

490-592: The 1960s on the Pratt & Whitney J58 and Rolls-Royce Turbomeca Adour , for example. They are also used to swivel the VTOL nozzle for the Rolls-Royce LiftSystem . The F414 continues to be improved, both through internal GE efforts and federally funded development programs. By 2006 GE had tested an Enhanced Durability Engine (EDE) with an advanced core. The EDE engine provided a 15% thrust increase or longer life without

525-629: The A-12 development program. In December 1990 Secretary of Defense Dick Cheney told the Navy to justify the program and deliver reasons why it should not be canceled. The response given by the Navy and the contractors failed to persuade the Secretary of Defense, as he canceled the program in the following month, on 7 January 1991, for breach of contract. "The A-12 I did terminate. It was not an easy decision to make because it's an important requirement that we're trying to fulfill. But no one could tell me how much

560-476: The F404 is the construction of the first three stages of the high-pressure compressor which are blisks rather than separate discs and dovetailed blades, saving 50 pounds (23 kg) in weight. The F414 uses a " fueldraulic " system to control the area of the convergent-divergent nozzle in the afterburner section. The nozzle actuators use engine fuel whereas the F404 uses an engine hydraulic system. "Fueldraulic" actuators for afterburner nozzles have been used since

595-622: The F404, and was designed to fit in the same footprint as the F404. The F414 uses the core and full-authority digital engine control (FADEC) from the F412, and the low-pressure system from the YF120 engine developed for the Advanced Tactical Fighter competition. One of the major differences between the F404 and the F414 is the fan section. The F414 fan is larger than that of the F404 , but smaller than

630-403: The F412 fan. The larger fan increases the engine airflow by 16%, is 5 inches (13 cm) longer, and increased diameter from 28 inches (71 cm) to 31 inches (79 cm). To keep the F414 in the same envelope, or space occupied in the airframe, as the F404, the afterburner section was shortened by 4 in (10 cm) and the combustor shortened by 1 in (2.5 cm). Also changed from

665-682: The U.S. prevented them from mounting an effective defense. In May 2011, the Supreme Court set aside the Appeals Court decision and returned the case to federal circuit court. In January 2014, the case was settled with Boeing and General Dynamics agreeing to pay $ 200 million each to the U.S. Navy. Data from Stealth Warplanes General characteristics Performance Armament Aircraft of comparable role, configuration, and era Related lists Specific fuel consumption (thrust) Thrust-specific fuel consumption ( TSFC )

700-566: The United States Air Force would be used heavily in the program. Concept design contracts were awarded to the industry teams of McDonnell Douglas / General Dynamics , and Northrop / Grumman / Vought in November 1984. The teams were awarded contracts for further concept development in 1986. The General Dynamics/McDonnell Douglas team was selected as the winner on 13 January 1988; the rival team led by Grumman surprisingly failed to submit

735-584: The cancellation have been debated and have been an issue of controversy. After the cancellation of the A-12, the Navy elected to purchase the F/A-18E/F Super Hornet , which went on to replace the A-6 Intruder and the F-14 Tomcat . The Super Hornet uses the General Electric F414 turbofan engine, which is a modified variant of the upgraded F404 version developed for the A-12. The full-size A-12 mockup

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770-540: The complexity of the radar system to be used also caused costs to increase; by one estimate the A-12 was to consume up to 70% of the Navy's budget for aircraft. After delays, its critical design review was successfully completed in October 1990 and the maiden flight was rescheduled to early 1992. In December 1990 plans were made for 14 Navy aircraft carriers to be equipped with a wing of 20 A-12s each. A government report released in November 1990 documented serious problems with

805-447: The customer. The following table gives the efficiency for several engines when running at 80% throttle, which is approximately what is used in cruising, giving a minimum SFC. The efficiency is the amount of power propelling the plane divided by the rate of energy consumption . Since the power equals thrust times speed, the efficiency is given by where V is speed and h is the energy content per unit mass of fuel (the higher heating value

840-444: The fuel efficiency of a particular engine design in that particular application. For instance, in aircraft, turbine (jet and turboprop) engines are typically much smaller and lighter than equivalently powerful piston engine designs, both properties reducing the levels of drag on the plane and reducing the amount of power needed to move the aircraft. Therefore, turbines are more efficient for aircraft propulsion than might be indicated by

875-596: The program was going to cost, even just through the full scale development phase, or when it would be available. And data that had been presented at one point a few months ago turned out to be invalid and inaccurate." Secretary of Defense Dick Cheney , 1991. The government felt the contractors could not complete the program and instructed them to repay most of the $ 2 billion that had been spent on A-12 development. McDonnell Douglas and General Dynamics disputed this in Federal Claims court . The reasons and causes for

910-606: The program's ability to deliver upon its objectives; these doubts led to the development program's cancellation in 1991. The manner of its cancellation was contested through litigation until a settlement was reached in January 2014. The United States Navy began the Advanced Tactical Aircraft (ATA) program in 1983. The program was to develop and field a replacement for the A-6 Intruder by 1994. Stealth technology developed for

945-529: The same ends as the mechanical variety. A new combustor would likely aim to reduce emissions by burning a higher percentage of the oxygen , thereby reducing the amount of oxygen available to bond with nitrogen forming the pollutant NO x . As of 2009, the F414-EDE was being developed and tested, under a United States Navy contract for a reduced specific fuel consumption (SFC) demonstrator engine. In addition, General Electric has tested F414 engines equipped with

980-412: The thrust increase. It has a six-stage high-pressure compressor (down from 7 stages in the standard F414) and an advanced high-pressure turbine. The new compressor should be about 3% more efficient. The new high-pressure turbine uses new materials and a new way of delivering cooling air to the blades. These changes should increase the turbine temperature capability by about 150 °F (83 °C). The EDE

1015-405: The two contractors to repay the U.S. government US$ 1.35 billion, plus interest charges of US$ 1.45 billion. Boeing , which had merged with McDonnell Douglas, and General Dynamics vowed to appeal the ruling. In September 2010, the U.S. Supreme Court said it would hear the two companies' arguments, that the government canceled the project improperly and that the use of the state secrets privilege by

1050-605: Was a proposed American attack aircraft from General Dynamics and McDonnell Douglas . It was to be an all-weather, carrier-based stealth bomber replacement for the Grumman A-6 Intruder in the United States Navy and Marine Corps . Its Avenger II name was taken from the Grumman TBF Avenger of World War II. The development of the A-12 was troubled by cost overruns and several delays, causing questions of

1085-419: Was designed to carry precision guided weapons internally, up to two AIM-120 AMRAAM air-to-air missiles, two AGM-88 HARM air-to-ground missiles and a complement of air-to-ground ordnance, including unguided or precision-guided bombs, could be carried in an internal weapons bay. It has been claimed that the A-12 was to be capable of delivering nuclear weapons held in its internal weapons bay as well. The A-12

General Electric F414 - Misplaced Pages Continue

1120-517: Was later renamed Fort Worth Aviation Museum . ) The manner in which the program was canceled led to years of litigation between the contractors and the Department of Defense over breach of contract ( General Dynamics Corp. v. United States ). On 1 June 2009, the U.S. Court of Appeals for the Federal Circuit ruled that the U.S. Navy was justified in canceling the contract. The ruling also required

1155-563: Was promoted as a possible replacement for the Air Force's General Dynamics F-111 Aardvark , and for the United Kingdom's Panavia Tornado fighter-bombers. The craft was a flying wing design in the shape of an isosceles triangle , with the cockpit situated near the apex of the triangle. The A-12 gained the nickname "Flying Dorito ". The aircraft was to be powered by two General Electric F412-D5F2 turbofan engines, each producing about 13,000 pounds-force (58  kN ) of thrust. It

1190-774: Was revealed to the public at the Naval Air Station Joint Reserve Base Fort Worth in June 1996. The cancellation of the A-12 is seen as one of the major losses in the 1990s that weakened McDonnell Douglas and led to its merger with rival Boeing in 1997. After years of being in storage at the Lockheed Martin Aeronautics (formerly General Dynamics) facility in Fort Worth, Texas, the mockup was transported to Veterans Memorial Air Park adjacent to Meacham Airport in north Fort Worth in June 2013. (The park

1225-456: Was to have a weapons load of 5,160 pounds (2,300 kg). Beginning in early 1990 General Dynamics and McDonnell Douglas revealed delays and projected cost increases. Due to late requirement changes to the aircraft impacting the composite design, aircraft weight had increased to 30% over design specification. This was unwelcome for an airplane that needed to operate efficiently and effectively from an aircraft carrier. Technical difficulties with

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