Previous-generation stealth aircraft such as the B-2 Spirit and F-117 Nighthawk were designed to be bombers, lacking the active electronically scanned array (AESA) radars, low probability of intercept (LPI) data networks, aerial performance, and air-to-air weapons necessary to engage other aircraft. In the early 1970s, various American design projects identified stealth, speed, and maneuverability as key characteristics of a next-generation air-to-air combat aircraft. This led to the Request for Information for the Advanced Tactical Fighter project in May 1981, which resulted in the F-22.
The USMC is leveraging the USAF's experience with "fifth-generation air warfare" in the F-22, as they develop their own tactics for the F-35.
According to Lockheed Martin, the only fifth-generation jet fighter currently in operational service is their own F-22 Raptor. US fighter manufacturer Lockheed Martin uses "fifth generation fighter" to describe the F-22 and F-35 fighters, with the definition including "advanced stealth", "extreme performance", "information fusion" and "advanced sustainment". Their definition no longer includes supercruise capability, which has typically been associated with the more advanced modern fighters, but which the F-35 lacks. Lockheed Martin attempted to trademark the term "5th generation fighters" in association with jet aircraft and structural parts thereof, and has a trademark for a logo with the term.
Russian and Chinese fifth-generation fighters are expected to enter further development/service in 2017, which is also the predicted year that the F-35 program will enter the same stages.
In the late 1980s, the Soviet Union outlined the need for a next-generation aircraft to replace the fourth-generation jet fighters Mikoyan MiG-29 and Sukhoi Su-27 in front line service. Two projects were proposed to meet this need: the 4.5 generation fighters Sukhoi Su-47 and Mikoyan Project 1.44 (although the MiG-35 was later modernized to 4.5 generation status). In 2002, Sukhoi was chosen to lead the design for the new combat aircraft.
As the first post-Soviet fighter, the fifth-generation jet fighter Sukhoi PAK FA will incorporate technology from both the Su-47 and the MiG 1.44 and when fully developed is intended to replace the MiG-29 and Su-27 in the Russian inventory. It serves as the basis of the Sukhoi/HAL FGFA project being developed with India. The PAK FA is designed to compete against the American F-22 Raptor and F-35 Lightning II. It performed its first flight on 29 January 2010 and the first production aircraft is slated for delivery to the Russian Air Force by 2017.
Russia is also constructing a lightweight stealth multirole fighter, the Mikoyan LMFS (MiG-1.27) by aircraft manufacturer Mikoyan. This jet fighter is based on the cancelled MiG-1.44.
By the late 1990s, several Chinese fifth-generation fighter programs, grouped under the program codename J-XX or XXJ, were identified by western intelligence sources. PLAAF officials have confirmed the existence of such a program, which they estimate will enter service between 2017–2019. Nevertheless, Robert Gates has claimed that the United States may possess as much as 20 times more "advanced stealth fighters" than China by 2020. By late 2010, two prototypes of the Chengdu J-20 had been constructed and were undergoing high-speed taxi trials. The J-20 made its first flight on 11 January 2011. On 26 December 2015, a new J-20 with serial number 2101 was seen leaving its Chengdu Aviation Corporation factory. It is believed to be the first of the low rate initial production (LRIP) aircraft. 2101 conducted its maiden flight on 18 January 2016.
Another stealth fighter design from SAC started to circulate on the internet in September 2011. In June 2012, photos about a possible prototype of F-60 being transferred on highway began to emerge on the internet. This aircraft was named Shenyang J-31 later, and made its maiden flight on 31 October 2012.
India is independently developing a twin-engine fifth-generation supermaneuverable stealth multirole fighter, called the HAL Advanced Medium Combat Aircraft (AMCA). It is being developed and designed by the Aeronautical Development Agency and will be produced by Hindustan Aeronautics Limited. DRDO defines AMCA as a fifth-generation-plus platform. Unofficial design work on the AMCA began in 2008, while official work started in 2011 and finished in 2014. The first flight is scheduled to occur in 2023–2024. It is a multirole combat aircraft designed for the air superiority, ground attack, bombing, intercepting, strike and other types of roles. It combines supercruise, stealth, advanced AESA radar, supermaneuverability, and advanced avionics to overcome and suppress previous generation fighter aircraft along with many ground and maritime defences. The AMCA is intended to be the successor to the SEPECAT Jaguar, Dassault Mirage 2000, MiG-23 and MiG-27 Bahadur in the Indian Air Force.
Another project of India is the Sukhoi/HAL Fifth Generation Fighter Aircraft (FGFA), which is a fifth-generation jet fighter being developed together by India and Russia. It is a derivative project of the PAK FA (T-50 is the prototype) being developed for the Russian Air Force. FGFA was the earlier designation for the Indian version, while the combined project is now called the Perspective Multi-Role Fighter (PMF). The completed FGFA will include a total of 43 improvements over the T-50, including stealth, supercruise, advanced sensors, networking and combat avionics. however the project is already four years delayed due to multiple issues. On 9 March 2015, media outlets reported that the both India and Russia agreed to reduce the aircraft delivery time from 92 months to 36 months with the signing of the final agreement. India is also ready to forego a 50:50 work share to prevent further delays from absorption of a new technology; both countries agreed to manufacture the first batch of aircraft in Russia and for subsequent batches to be manufactured by HAL. On 25 January 2016, it was reported that Russia and India have agreed to develop FGFA and lower investment cost to $4 billion for each nation. They will invest $1 billion in the first year and another $500 million per year for the following six years. The Indian Air Force plans to induct 60 FGFA fighters, down from an earlier estimate of around 120.
As of 2016, AMCA is under development and FGFA is under negotiation.
Japan is developing a prototype of a stealth jet fighter called the Mitsubishi X-2 Shinshin, previously referred to as the ATD-X. At the beginning of the twenty-first century, Japan, seeking to replace its aging fleet of fighter aircraft, began making overtures to the United States on the topic of purchasing several Lockheed Martin F-22 Raptor fighters for their own forces. However the U.S. Congress had banned the exporting of the aircraft in order to safeguard secrets of the aircraft's technology such as its extensive use of stealth; this rejection necessitated Japan's development of its own modern fighter, to be equipped with stealth features and other advanced systems.
A mock-up of the X-2 Shinshin was constructed and used to study the radar cross section in France in 2009. The first prototype rolled out in July 2014 and the aircraft made its first flight on 22 April 2016. The Mitsubishi X-2 Shinshin will enter service in JASDF in 2024 as Mitsubishi F-3.
In 2011 Turkish Aerospace Industries initiated a $20 million concept design phase for a fifth-generation air-to-air fighter, TAI TFX. During a State visit of the President of Turkey to Sweden on 13 March 2013, Türk Havacılık ve Uzay Sanayii AŞ (Turkish Aerospace Industries, TAI) signed an agreement with Sweden's Saab AB to provide design support services to Turkey for the TAI TFX program. Turkish Aerospace Industries has stated that the program will cost $120 billion (with engine development). Former Prime Minister Erdoğan has stated that Turkey has allocated the funds for development of the fuselage (less engine) and that it intends to have the TAI TFX fully operational prior to 2025.
On 8 January 2015, Prime Minister Ahmet Davutoğlu announced that the TFX program will be an entirely indigenous platform with no international support shelving any cooperation with Korea, Sweden, Brazil or Indonesia. On 13 March 2015 the Turkish Undersecretariat for Defence Industries (SSM) officially issued a Request for Information from Turkish companies which had the capacity "to perform the indigenous design, development and production activities of the first Turkish Fighter Aircraft to meet Turkish Armed Forces’ next generation fighter requirements", signalling the official start of the program.
Giovanni de Briganti has defined the defining elements of a fifth-generation fighter to be:Stealth
High maneuverability – which tends to include short-field capabilities.
Networked data fusion from sensors and avionics
In order to minimize their radar cross-section (RCS), all fifth-generation fighters use chines instead of standard leading edge extensions and lack canards, though the Sukhoi PAK FA T-50 has engine intake extensions that seem to function somewhat like canards and the Chengdu J-20 designers have chosen the agility enhancements of canards in spite of their poor stealth characteristics. They all have twin canted vertical tails (similar to a V-tail) also to minimize side RCS. Most fifth-generation fighters with supermaneuverability achieve it through thrust vectoring.
They all have internal weapon bays in order to avoid high RCS weapon pylons, but they all have external hardpoints on their wings for use on non-stealthy missions, such as the external fuel tanks the F-22 carries when deploying to a new theater.
All fifth-generation fighters have a high percentage of composite materials, in order to reduce RCS and weight.
All revealed fifth-generation fighters use commercial off-the-shelf main processors to directly control all sensors to form a consolidated view of the battlespace with both onboard and networked sensors, while previous-generation jet fighters used federated systems where each sensor or pod would present its own readings for the pilot to combine in their own mind a view of the battlespace. The F-22A was physically delivered without synthetic aperture radar (SAR) or situation awareness infra-red search and track. It will gain SAR later through software upgrades. However any flaw in these huge software systems can knock out supposedly unrelated aircraft systems and the complexity of a software defined aircraft can lead to a software crisis with additional costs and delays. By the end of 2013 the biggest concern with the F-35 program was software, especially the software required to do data fusion across the many sensors.
Sukhoi calls their expert system for sensor fusion the artificial intelligence of the PAK-FA.
An automatic software response to an overheat condition apparently has contributed to at least one fatal crash of an F-22.
The F-35 uses Software-defined radio systems, where common middleware controls Field-programmable gate arrays. Col. Arthur Tomassetti has said that the F-35 is a "software intensive airplane and software is easy to upgrade, as opposed to hardware."
In order to ease the addition of new software features, the F-35 has adopted a kernel and app separation of security responsibilities.
Steve O'Bryan of Lockheed Martin has said that the F-35 may gain the ability to operate UAVs through a future software upgrade. The USN is already planning to place its Unmanned Carrier-Launched Airborne Surveillance and Strike system under the control of a manned aircraft, to act as a flying missile magazine.
Fifth-generation jet fighters use the newest generation of high performance jet engines and only the American Pratt & Whitney F119 is fully developed. The engines for the F-35 are still under development, the Chinese are dependent on Russian engines, and even the Russians are falling short in the development of the latest jet engines.
The combination of stealthy airframes, stealthy sensors, and stealthy communications is designed to allow fifth-generation fighters to engage other aircraft before those targets are aware of their presence. Lt. Col. Gene McFalls of the USAF has said that sensor fusion will feed into inventory databases to precisely identify aircraft at a distance.
Sensor fusion and automatic target tracking are projected to give the fifth-generation jet fighter pilot a view of the battlespace superior to that of legacy AWACS aircraft that may be forced back from the front lines by increasing threats. Therefore, tactical control could be shifted forwards to the pilots in the fighters. Michael Wynne, former Secretary of the United States Air Force, has suggested elimination of the Boeing E-3 Sentry and Boeing E-8 Joint STARS in favor of more F-35s, simply because so much effort is being made by the Russians and Chinese to target these platforms that are built to commercial airliner standards.
However, the more powerful sensors, such as AESA radar which is able to operate in multiple modes at the same time, may present too much information for the single pilot in the F-22, F-35 and T-50 to adequately use. The Sukhoi/HAL FGFA offered a return to the two-seat configuration common in fourth generation strike fighters, but this was rejected over cost concerns.
There is ongoing research to apply Track-before-detect across Sensor fusion in the core CPU to allow fifth-generation fighters to engage targets that no single sensor has by itself detected. Probability theory is used to determine "what data to believe, when to believe and how much to believe".
These sensors produce too much data for the onboard computers to fully process so sensor fusion is achieved by comparing what is observed against preloaded threat libraries that contain known enemy capabilities for a given region. Items that do not match known threats are not even displayed.
Even committed fifth-generation fighter users such as the Israelis concede that advances in sensors and computing will overcome a pure stealth configuration within a decade. This is why the Israelis insisted that the F-35 have defined interfaces so that the electronic warfare systems could be constantly improved to match the threat. All known fifth-generation designs have extensive electronic warfare systems, partly in response to an incident where the limited EW systems on an F-117 may have led to its loss in combat. Stealth is now seen as "part of the overall electronic warfare issue", in that a stealthy platform is easier to hide with the assistance of jamming.
Chinese state media has claimed that their UHF JY-26 radar has tracked an F-22 on deployment to South Korea.
Gilmary M. Hostage III has suggested that fifth-generation jet fighters will operate together in a "combat cloud" along with future unmanned combat aircraft, and Manazir has suggested that this might come as quickly as loading a UCLASS with AMRAAMs to be launched at the command of an F-35.
The definition of the term fifth-generation fighter from Lockheed Martin has been criticized by companies whose products do not conform to these particular specifications, such as Boeing and Eurofighter, and by other commentators such as Bill Sweetman: "it is misleading to portray the F-22 and F-35 as a linear evolution in fighter design. Rather, they are a closely related pair of outliers, relying on a higher level of stealth as a key element of survivability – as the Lockheed YF-12 and Mikoyan MIG-25, in the 1960s, relied on speed and altitude."
The United States Navy and Boeing have placed the Boeing F/A-18E/F Super Hornet in a "next generation" fighter category along with the F-22 and F-35, as the Super Hornet has a "fifth-generation" AESA radar, modest radar cross-section (RCS) reductions and sensor fusion. A senior USAF pilot has complained about fifth-generation claims for the Super Hornet: "The whole point to fifth generation is the synergy of stealth, fusion and complete situational awareness. The point about fifth-generation aircraft is that they can do their mission anywhere – even in sophisticated integrated air defense [IADS] environments. If you fly into heavy IADS with a great radar and sensor fusion, but no stealth, you will have complete situational awareness of the guy that kills you." Michael “Ponch” Garcia of Raytheon has said that the addition of their AESA radars to the Super Hornet provides "90 percent of your fifth-generation capability at half the cost." And a top Boeing official has called their newest 4.5 generation fighters "stealth killers".
In response to the use of the "fifth generation" term, Eurofighter has made a fifth-generation checklist placing different weights on the various capabilities, and arguing that the application of the label to strike aircraft such as Lockheed-Martin's F-35 is ill-advised, and even inconsistent with the aircraft's specifications. Meanwhile, Eurofighter adds "net-enabled operations" as a noteworthy requirement and de-emphasizes full-scope low observability as only one factor in survivability. In the same article Eurofighter GmbH appear to acknowledge the remarkable performance of Lockheed Martin's F-22 aircraft, while demonstrating that labels as simple as "fifth generation" may easily be devised to serve the interests of the writer.
Richard A. Bitzinger of the S. Rajaratnam School of International Studies, a former consultant for the American RAND Corporation think tank, suggests that Western Europe's "failure" to develop a fifth-generation jet fighter may reduce these former leaders in the market to also-ran status as the world's attention shifts to the competition between the United States and Asian powers. Canadians Alex Wilner and Marco Wyss of the Center for Security Studies claim that Europe's failure to "keep up" with the F-35 may make the European jet fighter manufacturers close up shop. However, Europe may return with a trans-national 'sixth-generation' UCAV, assuming that the political entanglements can be evaded. The European Defence Agency has warned that the European $60 billion industry could collapse by 2020.
The Russian Defense Ministry defines fifth-generation as including "stealth technology, supersonic cruising speed, highly-integrated avionics, electronics and fire-control systems".