Avions de 5e et de 6e génération : entre réalité technologique et arguments marketing
5th and 6th generation aircraft: between technological reality and marketing arguments
11 October 2023
The last twenty years have seen the democratisation of the term "generation" to categorise and classify combat aircraft, with a 5th generation aircraft logically being more capable than a 4th generation aircraft.
While this classification is based on a historical reality, it also masks a desire to simplify a much more complex reality. While simplification makes it easier to communicate with the general public, it also allows powerful players, using tried and tested marketing tools, to induce biased concepts through sometimes fallacious arguments, trapping the various levels of politics and the media, who do not have the tools to challenge them.
You have to be a historian to find the beginnings of the use of the term "generation" when talking about fighter aircraft. Many publications by American intellectuals linked to the defence community shed light on the context in which this term was used, and the use they made of it. Among the dozens of works that can be consulted are the very interesting "World Combat Aircraft Inventories and Production: 1970-1975" (1), a confidential document for government agencies written in 1970 by the Arms Control Project at MIT, and "The New Old Threat: Fighter Upgrades and What They Mean for the USAF" (2), a thesis published in 1995 by Illinois State University.
The origins of the concept
In these two documents, the term "generation" is used to describe reality, and serves as a tool for establishing a classification (see illustration on next page). In this way, the authors create coherent sets of combat aircraft models, which they then separate according to certain criteria. Obvious facts emerge, such as the fact that a new generation of aircraft replaces an older one, or that their characteristics, whether comparable or not, make it possible to group or separate aircraft models. But at that point in history, there was no common convention among commentators to define precisely what a generation was or to establish a classification as we see today.
While the term 'generation' is used for the same purpose and with similar methods in both publications, in order to support the development of an idea, the characteristics chosen are not the same, resulting in very different rankings. Curiously, it is the work published in 1974 that is closest to the current classification, with a first generation selected from post-World War II aircraft production, and ending with the future 4th generation aircraft that will be the F-14 and F-15 then about to enter service. As far as the 1995 publication is concerned, the author starts the classification by including post-1939 aircraft, includes other characteristics, and separates the first and last versions of certain aircraft into two distinct generations (Mirage III and MiG-21 being found in both the 4th and 5th generations).
In 1998, in a thesis (3) defending the relevance of the F-22 in maintaining air dominance, John W. Day mentions other 5th generation aircraft that will enter production, notably the Eurofighter Typhoon and two variants of the Su-27, the Su-30 and the Su-35. The concept of "generation" refers more to the chronology of production than to an arbitrary list of physical characteristics or desired performance.
In comparison, in an article entitled "The Sixth Generation Fighter" published in October 2009 in Air Force Magazine (4), where the issue of classification is central, the definition and number of generations are no longer the result of observation or a desire to organise the complexity of reality more simply. Classification into generations is now considered both as a historical fact and as a convention on which there is now a consensus. A generation is no longer qualified solely by the fact that a more recent type of aircraft replaces an older one, but solely by its own characteristics, which are attached by default to this convention.
From observation to marketing use
Previously used as a qualifier based on observation, the term 'generation' has now begun to be used as a qualitative qualifier. In the space of a few years, it was no longer the aircraft that made the generation, but the generation that made the aircraft. The beginnings of this paradigm shift can be found in a Lockheed Martin Aeronautics document published in November 2000 under the title "Affordable Stealth" (5) which, although it does not mention the term 5th generation once, insists on the characteristics specific to the F-22 which enable the USAF to maintain its absolute superiority, even against nations equipped with aircraft chronologically just as recent as the F-22. The characteristics that are supposed to give the F-22 air supremacy are as follows:
- a low radar and infrared signature ("stealth or low observability" in the text), often summarised as "stealth";
- the ability to fly in supercruise, in other words to reach and maintain supersonic speed without using afterburner;
- agility at all speeds and altitudes;
- advanced avionics for improved situational awareness;
- high aircraft availability ("supportability" in the text).
In 2001, another article in Air Force Magazine (6) was one of the first to use two expressions that made Lockheed Martin's communications department very happy: "true 5th generation aircraft" to designate the F-22, and "4.5 generation aircraft" to designate all its competitors. Given the level of threat posed to US air superiority by extremely recent aircraft about to enter service, such as the Typhoon, Rafale and Su-35, all of which were superior to the F-16 and F-15, the F-22 was the one and only genuine new-generation aircraft to enter service, and would remain so for the next 20 years.
This description presents commentators with a dilemma. While there is no doubt that the entry into service of the F-22 fleet represents the 5th generation of air superiority aircraft since the creation of the US Air Force in 1947, a choice has just been made. To associate absolute superiority with number five. It was therefore no longer possible to qualify aircraft that might become adversaries as 5th generation, and so the need to create intermediate levels was born. In the (American) context in which the 2001 article was written, and in which USAF officers were quoted, the bias, while objectionable, is nevertheless based on a certain logic, however arrogant it may appear outside the US.
From then on, the term 5th generation was no longer associated with the aircraft that were to replace the 4th generation. What's more, to be eligible for this classification, it is no longer even necessary to meet the list of (arbitrary) criteria hitherto associated with the 5th generation. While Russian and European competitors are denied the "5th Gen" stamp and relegated to the rank of "4.5 generation" or "4+ generation", it is out of the question to deny this precious label to the new Joint Strike Fighter (future F-35), even though it does not meet this list of "superior" characteristics either. We are talking here about a purely qualitative term. A 5th generation aircraft is quite simply superior to a 4th generation aircraft, regardless of the missions it has to carry out or its own characteristics and performance. This simplification, worn to the bone by the communications departments, pushes the quality of the debates to the point of absurdity (see illustration opposite), but now makes it possible to impose a simple way of thinking, which serves a well-honed discourse. This is one of the greatest weapons of the 5th generation.
What generation are today's aircraft?
This is a tricky question to answer. In the past, the dynamic performance of aircraft was closely linked to their development. According to the commonly accepted categorisation of the first four generations of aircraft, each of them clearly surpassed the previous one in terms of structural design and, generally speaking, dynamic performance. But since the 4th generation, and with the exception of electromagnetic wave stealth ("EM and IR stealth"), it is mainly the avionics that have been marking time in the evolution of aircraft. While it is undeniable that the Rafale, F-22 and Super Hornet are superior to the Mirage 2000, F-15 and Hornet they replace, respectively, this superiority is due less to their ability to manoeuvre or their speed (which is sometimes lower, incidentally) than to the ability of their weapons system to understand their tactical environment, and to detect and deal with their target first.
To support this example, all you have to do is equip 4th generation aircraft with modern avionics, and they become aircraft capable of competing for air superiority with most of the next generation. In fact, the F-16V Block 70 and Mirage 2000-9 have nothing in common with the F-16A and Mirage 2000C launched in the late 1970s and early 1980s, even if they are now reaching their full development potential, usually because of a lack of power and internal volume. Of course, these upgrades and modernisations of older generation aircraft have not prevented the new arrivals from enjoying successful commercial careers. While the Eurofighter programme seems to be moving slowly, entangled in the throes of a complex multinational cooperation in which potential modernisation budgets are competing with the acquisition of the F-35, the situation is quite different for other aircraft. This is the case in France, which has taken the gamble of equipping the Rafale with a completely modular and upgradeable architecture that allows for almost limitless improvements, without the need to develop a completely new aircraft or new standards from scratch. The Rafale F4 standard, which is starting to be delivered to the French armed forces, offers far superior capabilities to the first versions of the aircraft, in terms of on-board avionics, weapons, communications and electronic warfare. The aircraft is expected to remain operational until 2060, and will certainly remain in production until its successor arrives. With the various standards coming one after the other, who can predict what capabilities the aircraft will have by 2030? Will it be inferior to the F-35? By what criteria? And what capabilities will the F-35 or the F-15EX have in 20 years' time? The very long genesis of these aircraft and their even longer lifespan mean that the equipment on board their airframes is and will be replaced several times during their (very long) operational life.
Towards a new generation?
While the appearance of previous generations offered an undeniable leap forward in terms of capabilities, we now have to deal with incremental improvements. To date, no truly revolutionary technological or capability building block has been clearly identified - which would mean developing radically different aircraft in the short term. This is why, for the 6th generation, it is no longer a question of simply designing a new fighter aircraft, but of developing systems of systems. This notion is at the heart of the main programmes that claim to be 6th generation, namely the two NGAD programmes (Next Generation Air Dominance) run in parallel by the US Air Force and the US Navy, the SCAF programme (Future Air Combat System), led by France, Germany and Spain, and the GCAP (Global Combat Air Programme) which merges the Italian-British Tempest and the Japanese F-X.
Of course, the development of a new airframe and new engines is seen as essential, both for the armed forces and for national manufacturers. For the air force, it is obviously a question of being able to take advantage of all the technological developments that have appeared over the last twenty years, and which can only be partially exploited on board old, modernised aircraft. A new aircraft will therefore be able to overcome certain limitations linked to the use of modern systems that consume more and more electricity, which has to be produced, but whose heat also has to be dissipated. For manufacturers and equipment suppliers, the aim is to maintain knowledge within the design offices, but also to develop technologies that can be used in other programmes, particularly in civil aviation.
However, unless we direct the future of combat aviation towards areas inaccessible to current aircraft, such as the very high atmosphere, or even the edge of space, or highly supersonic or even hypersonic cruise speeds, and unless we imagine the widespread use of revolutionary new weapons, There is no integrated air defence system that absolutely requires the rapid replacement of all fighters currently in service or in production by a brand new combat aircraft. This is why it is already planned that the new systems developed for the SCAF will be considered as technological building blocks for which the aircraft is only a carrier. Moreover, in a system-of-systems approach, combat aircraft would be just one of a number of effectors, whether airborne, ground-based or placed in orbit. So the Rafale (and perhaps the German Eurofighter Typhoon) would be equipped with some of the SCAF systems, and would be fully integrated into the SCAF system of systems via the combat cloud. The new aircraft that could be designed and built specifically for these 6th generation systems would have the advantage of being able to integrate all the technological building blocks natively, and would offer dynamic performance (speed, altitude, range) better adapted to the current operational context. However, as they will be more expensive and heavier, there will probably be fewer of them, and they will only be fully operational if they operate as part of a meshed network of mission aircraft, detection and combat drones and... modernised old-generation fighters. As part of the NGAD programme, the USAF recently confirmed the acquisition of 1,000 CCA UAVs, which will operate alongside 200 new-generation fighters, as well as 300 F-35As, initially. So can we still talk about a new generation of fighter aircraft when we are talking about the NGF (the SCAF's manned aircraft) or the F/A-XX (the US Navy's NGAD manned aircraft), given that these vectors will only be building blocks within a complex and evolving system of systems? It might make more sense to talk about 6th generation systems, rather than 6th generation aircraft.
"6th generation"
Leaving aside everything that has just been written about the difficulty of precisely defining what a generation is, and even going back to the most "simplistic" discourses, there is currently no clear definition of what the capabilities of a 6th generation combat aircraft would be. While work is underway, it is essentially prospective. This is understandable, as no one has yet defined what the future battlefield will look like in the third dimension.
So mistrust is the order of the day when it comes to possible developments. At best, we can safely say that the future of combat aviation will be ultra-connected, which is how the battlefield has evolved since the advent of radio to the systematic use of Link-16, with AWACS detection and communication nodes. The F-35 programme has paid a great deal of attention to intra-patrol communication, enabling new combat tactics to be established. Naturally, the development of communications, networks and information processing resources will make it possible to process quantities of data that will make today's on-board computers seem like ordinary calculators. Electromagnetic discretion will undoubtedly be improved, as will data fusion and tactical integration in the battlefield, whether airborne, naval or land-based (or even space-based). Both active and passive sensors will undergo technological improvements, some of which have already been identified. As far as weapons are concerned, high-power lasers and electromagnetic pulse weapons could be on the horizon in the next few decades.
In areas that require a real technological breakthrough, such as very high speeds and altitudes, we are witnessing a wait-and-see attitude. The first country to be able to break new ground in these areas will have to find unprecedented solutions and bear a staggering development cost. But if the solution or solutions become realistic, then all enemies and/or competitors will have to catch up, otherwise an army might be able to operate in an environment without being troubled by threats that have become obsolete.
So, 5th or 6th generation?
From a historical or pragmatic point of view, classifying combat aircraft generations today no longer makes much sense. You could say that the same aircraft stay the same, but no longer look the same. Who could have said that the venerable F-16, which made its first flight in 1974, would still be relevant and in production in 2023? The various blocks have undergone major developments, to the point where it is conceivable that one and the same aircraft could have the characteristics of three different generations of fighter aircraft. The aircraft currently in production have a future that is likely to be at least as long: which just goes to show how there is no need to be in a hurry to see the arrival of revolutionary new combat aircraft, whose generation number will then be of little interest.
Notes
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1)
https://apps.dtic.mil/sti/pdfs/AD0869768.pdf
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2)
The New Old Threat: Fighter Upgrades and What They Mean for the USAF,
(
3)
Defending the F-22
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4)
https://www.airandspaceforces.com/PDF/MagazineArchive/Documents/2009/October 2009/1009fighter.pdf
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5)
https://www.kimerius.com/app/download/5782357818/Affordable+Stealth.pdf
(
6)
https://www.airandspaceforces.com/PDF/MagazineArchive/Documents/2001/October 2001/1001fighter.pdf
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