Why ‘Next-Gen’ Will Include Non-Stealth Fighters

In February 2021, the U.S. Air Force’s (USAF) Chief of Staff, General Charles “CQ” Brown, revealed that the USAF will study the idea of developing a clean-sheet fourth-generation fighter to replace its F-16s.[1] Brown added that the Air Force will also consider new-build F-16s (e.g., the Block-70/72) to replace old versions.[2]

The main driver for the study is a revised look at an optimal fleet composition. The Air Force is seeking to build the “right force mix” comprising of “high-end” and “low-end” fighters.

The “high-end” will comprise of fifth-generation fighters, such as the F-22 and F-35, and the upcoming Next-Generation Air Dominance (NGAD) platform.[3] The “low-end” is still an open question. The Air Force is interested in the value of an F-16-type aircraft, but not necessarily the F-16 itself.[4]

Thus, the study could potentially open the discussion to ‘next-generation’ fighters that do not emphasize low observability (LO) on radar as much as the F-22 or F-35. Interestingly, the U.S. is not the only country studying or working towards this concept. South Korea will soon fly its KF-21 Boramae and India is looking at developing its own carrier-capable jet, the Twin-Engine Deck-Based Fighter (TEDBF).

One could say that these fighters are not much different from existing 4.5-generation aircraft, such as the Rafale, Typhoon, or Gripen E/F. However, in contrast to older 4.5-generation fighters, these new platforms were designed to incorporate new technologies, such as active electronically-scanned array (AESA) radars and others, from the onset. In that sense, a ‘new’ 4.5-generation fighter is starting from a different league compared to its older counterparts. In fact, even the development process for these jets may be different.

One area of interest to the USAF is the use of digital engineering in the design process. They had employed digital engineering to design, develop, and fly the NGAD within a relatively short period of time. Likewise, the T-7 Red Hawk trainer had undergone a similar design and development process.

It is possible that this new clean-sheet 4.5-generation fighter could emerge in the same manner. However, with a digital engineering approach, the U.S. could test and validate aspects of the fighter (e.g., new types of subsystems and technologies) before rolling out a prototype.

In other words, being “low-end” or even “non-stealth” should not dismiss this 4.5-generation fighter’s technology or capabilities. It could still be a capable and advanced platform, but without niche features, such as internal weapon bays. For example, it is unlikely that this fighter would lack the ability to use loyal wingman or unmanned air-teaming networks, but this is a beyond fifth-generation capability.

Thus, the definition of a ‘next-generation’ fighter may change in the coming years. Instead of a strict and narrow continuum where one expects next-generation fighters to have internal bays, one may see a world where there are multiple types of next-generation fighters. Some would fulfill specific roles, such as deep-strike and maritime operations, while others are more generalist in design.

It will be interesting to see how closely the U.S. links the clean-sheet design to the “Digital Century Series” model. The Digital Century Series model envisaged the use of digital engineering and other new methods to develop inherently lower-cost (but technologically advanced and capable) fighters at a more frequent cadence. So, instead of replacing a fighter type every 30 to 40 years, the U.S. could supplant fighters with new types every 10 to 15 years, much like it had through the 1950s and 1960s.[5]

Thus, the USAF’s ‘low-end’ fighter studies could draw more on the Digital Century Series by narrowing in on cost-control and expendability (i.e., the ability to replace the fighters every 10 to 15 years). Basically, the U.S. may develop multiple types of these fighters to support the USAF’s needs through the long-term.

India’s TEDBF and ORCA Concepts

Hindustan Aeronautics Limited (HAL) is proposing the Twin-Engine Deck-Based Fighter (TEDBF) to the Indian Navy (IN). Though the design mock-ups show a focus on radar cross-section (RCS) reduction, the TEDBF does not emphasize stealth as the HAL Advanced Medium Combat Aircraft (AMCA).

Rather, the goal to TEDBF is to deliver an optimal carrier fighter for the IN, even if the outcome leans closer to 4.5-generation designs. However, it is still a ‘next-generation’ fighter in the sense that it will be developed based on current and emerging technologies and design methods. HAL is studying a land-based air force variant – Omni-Role Combat Aircraft (ORCA) – for the Indian Air Force (IAF).

It seems that India is of the view that it is not feasible or effective to maintain a future fleet of only stealth-focused fighters, such as the AMCA. Interestingly, if India’s plans come to fruition, it could have three new fighters – i.e., AMCA, ORCA and TEDBF – built on common critical inputs, such as engines, avionics, air-to-air and air-to-surface munitions, and sensors. Through digital engineering, India may be able to identify more areas of commonality (e.g., certain aerostructure components).

In any case, India is already looking to shift its next-generation fighter fleet plans towards a mix of stealth-focused and more generalist, non-stealth designs. Besides the high-cost of moving to a pure AMCA-type fleet, the other reason for having the TEDBF and ORCA is that the latter two can be optimized for specific goals. Certain operational roles may be better handled by a TEDBF or ORCA-type fighter than an AMCA.

Looking at Pakistan’s ‘Next-Generation’ Goals

In statements to ARY News, the previous Pakistan Air Force (PAF) Chief of Air Staff (CAS), Air Chief Marshal (ACM) Mujahid Anwar Khan, reportedly said that the PAF will transition to an ‘all-next-generation fleet’ by 2047 (i.e., Pakistan’s centennial anniversary).

The PAF is studying its FGFA options through Project AZM, but the design it is pursuing (i.e., a twin-engine aircraft with supercruising) is not something it can build an entire fleet around. Moreover, the JF-17 – i.e., its workhorse fighter – will age through the 2030s and 2040s and, eventually, require replacing. Thus, the PAF could acquire a lighter next-generation fighter to complement Project AZM by 2047.

This could manifest in the form of an existing off-the-shelf design, such as the J-10CE, or take the form of another in-house fighter program following Project AZM. Ultimately, the PAF is likely to collaborate with another country to achieve its FGFA aspirations, potentially by joining a consortium (such as Turkey’s TFX). However, a joint-venture on the FGFA need not dampen Pakistan’s indigenization aspirations.

As discussed in an earlier article, it takes decades to build the research, development, and industrial base to support an indigenous fighter program. The PAF had always raised collaboration as an option for Project AZM, provided its partner commits to an ITAR-free fighter. Thus, while AZM could roll into a collaborative project, the PAF could still support a parallel in-house fighter, but on a longer-term timeframe (e.g., aiming for production in the 2040s instead of the 2030s).

Likewise, the PAF need not focus on creating a complex, trailblazing design, but rather, it could focus on producing a solution that can feasibly replace the JF-17. As long as the subsystems (e.g., AESA radar) are contemporary, the PAF can focus on a comparatively simpler approach. In a sense, such a fighter could be a ‘new JF-17’ in the sense that it carries the same cost-control focus, but with new inputs that the JF-17 does not have (e.g., relaxed stability design, heavier composite material use, and more powerful engine).

[1] Valerie Insinna. “US Air Force eyes budget-conscious, clean-sheet fighter jet to replace the F-16.” Defense News. 18 February 2021. URL: https://www.defensenews.com/air/2021/02/18/the-air-force-is-interested-in-buying-a-budget-conscious-clean-sheet-fighter-to-replace-the-f-16/

[2] Ibid.

[3] Garrett Reim. “USAF rethinks future fleet, ponders clean-sheet 4.5-generation fighter.” Flight Global. 17 February 2021. URL: https://www.flightglobal.com/fixed-wing/usaf-rethinks-future-fleet-ponders-clean-sheet-45-generation-fighter/142471.article

[4] Ibid.

[5] Valerie Insinna. “The US Air Force has built and flown a mysterious full-scale prototype of its future fighter jet.” Defense News. 15 September 2020. URL: https://www.defensenews.com/breaking-news/2020/09/15/the-us-air-force-has-built-and-flown-a-mysterious-full-scale-prototype-of-its-future-fighter-jet/