Technology is an essential part of warfare, especially in the modern era. Looking at the 1991 Gulf War, it is unlikely that the Coalition would have won so decisively without its enormous advantage in this respect. Sixth-generation fighters continue this tradition. Having said this, not all technology is created equal. A rifle from the mid-1960s versus a rifle today will be at a disadvantage but is still quite usable and can be modernised for relatively little. The United States (US) still utilises a mid-century design in its AR15 platforms, albeit with many upgrades. Armour is in a similar position; Turkey still uses an upgraded M60, which entered US service in 1959 (source).
The same trends described above do not necessarily apply to air warfare. Great power air forces must be on the cutting edge at all times to utilise the devastating power of airpower in a conflict. An example of this in action can be seen, once again, in the middle east. During the Iran-Iraq war (1980 – 1988), Iranian third and fourth-generation fighters contested the skies with Iraqi second and third-generation fighters (source)(source). The result? Iranian domination in the first phase of the war (source). Only when modern French Mirage F1s began to arrive in Iraq did the tide turn (source).
While air power did not play an instrumental part in its conclusion, the lessons of the Iran-Iraq war are important to consider (source). In aerial combat, advanced technology is a force multiplier (source).
In the modern era, nations are already looking at a new generation of aircraft with which to control the skies. Sixth-generation aircraft represent the aerial battleground of the future. This article seeks to examine the current projects of various nations. Doing so will highlight the expected capabilities and issues with each programme.
1.0: Aircraft Generations
Generations are a handy way to reference aircraft from a specific period. By virtue of this, these aircraft will have similar design characteristics. Variable geometry, an element of advanced third and fourth-generation aircraft, would not be present in advanced fourth or fifth-generation aircraft due to advances in material sciences and computer modelling, as well as economic and maintenance considerations (source). While useful in the past, engineers have deemed variable swept wing designs obsolete.
Having said this, generations are by no means universally accepted. There are numerous different definitions of what precisely a generation entails, where the start and stop points are, and what design characteristics they have. What follows below is just one perspective, but may prove helpful in any case.
These are the earliest jet fighters (source). These include the Me262 and the Gloster Meteor, both of which participated in World War II (source). These aircraft have a notable performance improvement over piston-engine fighters (source). First-gen aircraft usually had straight wings and were capable of sub-sonic flight (source).
Noticeable improvements to first-gen fighters followed quickly after their introduction; second-gen fighters were the most visible aspects of the Korean War (1950 – 1953), including the F-86 Sabre and the MiG-15 (source). These fighters began to improve upon the performance capabilities that jet engines allowed through design choices like swept wings (source). Additionally, these jets were capable of transonic speeds and could carry primitive heat-seeking missiles (source).
Air forces introduced third-gen aircraft in the late 50s and early 60s (source). Notable jets of this era include the F-4 Phantom and the MiG-21 (source). Technological improvements created aircraft with more advanced missiles, higher speeds, and improved radar than earlier generations (source). Also seen in this generation is the first introduction of beyond-visual-range (BVR) combat by virtue of the first radar-guided missiles (source).
First introduced in the 1970s, air forces worldwide still operate fourth-gen fighters (source). The F-15, F-16, Su-27 and MiG-29 are all examples (source). Similar to prior trends, this generation expands on the capabilities of the previous with better engines, weapons, sensors and radars (source). Additionally, this generation sees conscious design for extensive BVR combat as well as multi-role designs (source). Because they are so prolific, upgrades to fourth-gen fighters have spawned a 4.5-gen classification notable for modernised avionics, radar, and stealth design elements (source).
The most recent generation came into being with the introduction of the F-22 Raptor in 2005 (source). Other examples include the F-35 Lightning II, the SU-57, and the J-20 (source). Fifth-gen aircraft are stealthy; for this purpose, they come with internal storage bays for weapons to further reduce radar cross-section (RCS) (source). Additionally, fifth-gen aircraft have networking capabilities, significantly increasing situational awareness and acting as command centres for other generations of aircraft (source).
As sixth-generation aircraft are currently in development, a concrete definition is difficult to come by. Additionally, different countries assign different capabilities to sixth-gen aircraft and will design around this understanding. However, a definition helps determine the general characteristics of the generation. John A. Tirpak (the Editorial Director of Air & Space Forces Magazine), writing in 2009, hypothesised that elements would include;
- Manned-Unmanned Teaming (MUM-T), including an unmanned wingman.
- Greatly enhanced data acquisition and data control (source).
- The ability to conduct electronic warfare (EW) (source).
- Replacement of electronics with photonics and extensive use of EW-resistant fibre optics (source).
- Enhanced stealth compared to fifth-gen aircraft, enabling deep penetration of contested airspaces (source).
These attributes apply to all of the sixth-generation fighters described below. Additionally, it is essential to note that sixth-generation programmes are components of a broader system. Lastly, much of the information available is inferred based on press statements, program requirements and so on. Therefore, the following sections have a great deal of speculation (with the exception of the Tempest).
3.0: Tempest Future Combat Air System (Italy, Japan, Sweden & the United Kingdom (UK))
The Global Combat Air Programme (GCAP) is a UK-led programme, with the sixth-generation Tempest future combat air system (FCAS) at its core. This programme began in 2018 with the launch of the UK’s Combat Air Strategy project (source). The Royal Air Force will use it to replace the Eurofighter Typhoon (source). In 2019, the UK arranged with Italy and Sweden to cooperate on the programme, bringing essential capital, resources, and industry (source). A trilateral agreement was signed in 2020 (source).
The programme began in earnest in 2021 (source). Team Tempest, headed by BAE Systems, won a Ministry of Defense (MoD) contract worth £250 million for the initial stage of the programme (source). Soon after, Japan began to assist in creating an engine demonstrator (source). By 2022, Japan was brought on as a full partner, merging their F-X programme into the development of Tempest FACS (source). This had the effect of pushing Sweden to the “margins” of the program (source).
In terms of capabilities, the Tempest FACS has several characteristics, including;
- Open and adaptable physical architecture to enable incorporation of future developments and different mission profiles (source).
- Construction is based on composite materials and additives to allow for operation at higher temperatures, suggesting high-speed and high-altitude performance (source). Additionally, these function to reduce thermal signatures (source).
- Scalable autonomy allows manned, unmanned, and optionally manned operations (source)(source).
- Integration with existing, planned, and future weapons systems (source).
- Interactive cockpit displays operating through augmented (AR) and virtual reality (VR) (source).
- Integrated communications, sensors, and effects, the latter of which enables EW (source). Combat Cloud technology allows fighters to share information on enemy contacts, terrain, and targeting data (source).
- Directed energy weapons (DEW) weapons for point defence (source).
- Additionally, the programme is designed around ease of manufacturing (source).
What this last point entails is unclear, though it is likely to rely extensively on automated manufacturing and hopefully cut production costs (source). Additionally, maintenance strains will be reduced via an automated support capability, “fully deployable to operation locations” (source).
As a multi-national programme, the Tempest is victim to the issues that colour these efforts. Different partners have different expectations of the aircraft. At worst, these result in project failure. The failed MBT-70, designed during the Cold War, is an example of this. The US and West Germany tried to jointly develop a NATO main battle tank (MBT) (source). This failed due to differing design views, namely the main gun and engine (source). The result of the programme was a tank that neither partner wanted. The US and West Germany went their separate ways and developed their own tanks, the M1 Abrams and Leopard II, respectively. While these developed with the help of technology from the original MBT-70 programme, it was still “a massive failure” that cost millions of dollars (source). The marginalisation of Sweden points to this already happening in a limited fashion.
3.2.1: Financial Concerns
However, unlike the MBT-70, where the US and West Germany were able to develop their own successful designs, sixth-generation fighters are likely far too costly to approach unilaterally. In 2019, the estimated cost of a new MBT development programme was around $1.2 billion (source). The UK has already devoted £2 billion to the Tempest FACS programme (source). British development costs are estimated to be £25 billion, while the Japanese government plans on spending at least $40 billion (source)(source). No partner within the Tempest programme could afford development costs as high as this, which are likely to increase if history is any standard (source).
4.0: Next Generation Fighter (France, Germany & Spain)
The Future Combat Air System (FCAS) programme started in 2018 as part of the European Union (EU) defence integration project (source). Germany and Spain both approached Airbus, a French company, to replace their ageing Eurofighter inventories (source). By 2018, Germany and France had agreed on the joint development of a Next Generation Fighter (NGF), bringing in Dassault to the programme (source). The French wanted to replace their Rafale fighters (source). Later that year, the two initiatives merged when Spain joined the programme as a full partner (source).
The NGF sixth-generation fighter was expected to become available in demonstrator form by 2029 and adopted by 2040 (source). However, Dassault’s CEO, Éric Trappier, has suggested that the latter date may be pushed back to the 2050s (source).
Compared to the Tempest FACS, there is little information on the NGF’s expected capabilities. This is likely because of the numerous delays and issues within the programme (source). As with Tempest, the description of sixth-generation fighters above applies to NGF. What is known is listed below.
- Artificial intelligence (AI) integration via the Air Superiority Tactical Assistance Real-Time Execution System (ASTARTES) (source).
- Use of a data cloud to share information between different components of a battlespace, including air, ground, and naval assets (source).
- Extended range and greater capacity for munitions compared to previous generations (source).
- Remote Carrier (RC) integration (source). RCs are loitering munitions with the “means to suppress or destroy enemy air defenses (SEAD/DEAD) like the S-400, conduct intelligence, surveillance and reconnaissance (ISR), electronic warfare, battle damage assessment, and even launch missiles against other aircraft” (source).
- The ability to launch from an aircraft carrier (source).
Similar to the issues described in the Tempest FCAS section, the NGF will face difficulty due to the multi-national nature of the FCAS programme. Problems with this program are already readily apparent (source). Issues over licensing, technology sharing, and production have already delayed the program several years, leading to Tapper’s 2050 comment (source)(source). However, these have been resolved for now (source).
4.2.1: The Problem with Carrier Capabilities
The biggest issue facing the NGF programme is the French requirement that the NGF is carrier capable. Carrier aircraft require different designs compared to aircraft flown from static runways on land. There is a historical precedent for this issue. France pulled out of the Eurofighter program to develop the Rafale, as the former did not meet their expectations of a carrier-capable aircraft. This same development is unlikely, given French industrial investment in the program, but it is still worth mentioning. Issues in accommodating this design aspect led to the US developing a wholly separate variant of the F-35 capable of carrier operations, the C model (source). Even this approach faced challenges. When asked about the design process of the F-35, Lieutenant General Christopher Bogdan of the US Air Force stated, “I’m not saying (joint programs are) good, I’m not saying they’re bad. I’m just saying, they’re hard” (source).
Carrier-launch capability might serve to increase conflicts in design and mission between the partners. Germany and Spain may not want a vehicle designed for French needs. This raises another issue, also seen in the F-35; part commonality. Though initially planning to have 70 per cent part commonality, the three F-35 variants only have 20-25 per cent part commonality (source). In other words, the models have almost wholly different manufacturing lines, which increases costs across the board (source). Once again, the financial cost is an important consideration. The nations have recently invested €3.2 billion into the FACS sixth-generation programme (source). Total costs are expected to be roughly €100 billion (source). If the F-35 is suggestive of cutting-edge technological development, this may double (source). NGF may face substantial financial limitations, especially given German hesitation to increase its defence budget even in the face of the Russo-Ukranian War (source).
5.0: Penetrating Counterair & F/A-XX (US Air Force & Navy)
The US Next Generation Air Dominance Programmes (NGAD) are two concurrent and identically named sixth-generation programs operated by the US Air Force (USAF) and Navy (source). The manned components in these programs are the Penetrating Counterair (PCA) of the USAF and the F/A-XX of the Navy (source)(source). The PCA will replace the F-22, while the F/A-XX will replace the F/A-18 (source)(source).
The USAF program, which looks to be more developed than the Navys, has been ongoing since at least 2015, and very likely existed in some form before this date (source). The first flight of a USAF demonstrator occurred in 2020, though details remain highly classified (source). As of June 2022, $4.2 billion had been set aside for developing the USAF NGAD programme (source). Frank Kendall, the Secretary of the Air Force, has announced that the engineering, manufacture, and design of the PCA is currently a work in progress (source).
While functionally different aircraft, the sixth-generation PCA and F/A-XX will incorporate similar technology and mission profiles (source)(source). As such, they will be discussed together here, and models will be specified as necessary.
- Supercruise capability (source)(source).
- Significantly extended range for Pacific operations (source)(source).
- The PCA (at least) will be “orders of magnitude” more stealthy than current fifth-gen fighters (source).
- Open architecture, for similar reasons to Tempest (source)(source).
- DEW for point defence and (possibly) offensive use (source)(source).
- Incorporating extreme long-range weapons, such as the AIM-260A Joint Advanced Tactical Missile and hypersonic munitions (source)(source).
- Advanced data sharing and communications (source).
- Carrier capability for the F/A-XX (source).
- Infrared search-and-track systems to identify stealth aircraft through heat signatures, at least for the PCA (source).
NGAD is hugely ambitious. The greatest challenge is in engineering. Though there have been tremendous advances in engine technology, creating an aircraft that can operate relatively isolated in the Pacific imposes significant design constraints because of the need for extensive fuel capacity (source).
The “orders of magnitude” quote may be hyperbole, but this is another aspect to consider if it is not. An order of magnitude is ten times the value of a given number. The RCS of an F-22 is .0001m², the size of a bumble bee (source). If the PCA is just two orders of magnitude more stealthy than the aircraft it is replacing, such an increase would necessitate radical structural designs (source). This, in turn, would make the supercruise requirement challenging to reach because stealthy shapes are not aerodynamic, which would necessitate more powerful engines, consuming more fuel and thus expanding the limitations imposed by fuel requirements, etc. (source).
Having said this, the USAF flew a demonstrator aircraft in 2020, so the programme is developing regardless of the challenges presented above (source). Indeed, a 2022 congressional report implied that the PCA would not resemble a traditional fighter; looking at the above, there is little wonder why (source).
5.2.1: Financial Concerns
The USAF requested $1.66 billion to develop the program through 2023 (source). They anticipate spending an additional $11.7 billion from 2024 – 2027 (source). Legislative approval for such a vast expenditure is by no means guaranteed, especially given prior experience with overrun costs with the F-35 and the classified and thus limited oversight of the project (source). If this were the case, the USAF and Navy may attempt to design or procure a low-cost alternative, as seen in the design ethos of the F-16 (source). This, in turn, could see a situation similar to the F-22 and B-2, where the cancellation of the orders increased the price of individual units substantially. In addition, NGAD is an incredibly expensive program without these developments, likely costing several hundreds of millions per aircraft (source).
Once again, this is by no means a full list of sixth-gen capabilities or programs. A large portion of this article is speculation, as these programs are either in early development, highly classified, or both.
Sixth-generation aircraft are looming on the horizon, and Western nations seem ahead of the curve. China, India and Russia have all claimed to be in the process of producing their own sixth-gen fighters, but most of these are dubious at best (source)(source)(source). Chinese efforts are the most likely to bear fruit, as they have successfully designed and adopted the fifth-gen J-20 (source). Unfortunately, there is no openly available information on Chinese sixth-generation efforts. India has no indigenous fifth-gen production capabilities, and, as can be seen from the information above, the leap from fifth-gen to sixth-gen is difficult even for nations producing fifth-gen fighters. Lastly, Russia only has between three and 15 SU-57s, which does not bode well for a sixth-gen programme (source).