America's Sixth Generation Fighters: The F-X and F/A-XX - I

Image 1: Early sixth generation concept by Lockheed Martin

In recent weeks, senior Air Force, Navy, and Pentagon officials have discussed ambitious plans to design a pair of sixth generation aircraft that will succeed the F/A-18E/F (F/A-XX program) and F-22A (F-X program) in the 2030 to 2035 time frame.

• Part I will discuss the need for a sixth generation fighter given the ongoing development of the capable fifth generation F-35 and the threat environment of 2030. 
• Part II will examine the state of development in both programs, the technologies that will be incorporated into the design which will define sixth generation capabilities. 
• Part III will review key design characteristics and the likely roles and missions of the two aircraft in their respective services. The author will subsequently examine the relative merits of the Air Force and Navy's F-X and F/A-XX concepts given the range of threats posed in an A2/AD environment. Finally, the author will conclude by examining the prospects of upgrading the F-35 with many of the sixth generation capabilities detailed throughout the article.
• Part IV - Works Cited 

The Need for a Sixth Generation Fighter 

Given that the fifth generation F-35 has yet to enter service, it may seem odd that both the Navy and Air Force are planning new sixth generation designs. Four principal of factors have guided the services decision to begin work on the F/A-XX and F-X programs: increasingly sophisticated anti-access threats, the potential compromise of key F-35 program details to China, the age and finite quantity of existing air superiority/air dominance platforms in conjunction with the proliferation of foreign fifth generation aircraft, and industrial base concerns. 

In 2001, Lockheed Martin's X-35 was selected over Boeing's X-32 for the Joint Strike Fighter program and was to be developed into the F-35 which was scheduled to enter service in April of 2010 for the Marines, June 2011 for the Air Force, and April 2012 for the Navy (Anthony Capaccio, 2013). As of 2015, the planned initial operational capability (IOC) dates for the F-35 are 2015 for the Marines, 2016 for the Air Force, and 2018 for the Navy. The significant delay in the development of the F-35 program has enabled US competitors, chiefly China and Russia, to start to develop technologies that would somewhat limit the effectiveness of the F-35's low observability. The proliferation of very high frequency (VHF) radars is a cause for concern as the F-35's airframe is optimized to perform against X and S band radars. As per the Raleigh scattering region, electromagnetic radiation will scatter from bodies smaller than its wavelength (Plopsky & Bozzato, 2014). In comparatively small stealth aircraft that place a premium on maneuverability such as the F-22, F-35, PAK FA, and J-20, the wing edges, tail fins, and other flight surfaces will inevitably be smaller than the 1 to 3 meter wavelength of VHF radars. However, VHF radars are not a panacea type solution to countering stealth aircraft.

Image 2: Raleigh scattering region. Image Credit: Air Power Australia

Historically, VHF radars have been of limited use as the resolution cells are too large too provide a target quality track for weapons systems unlike the X and S bands (Majumdar, 2014). China and Russia have recently applied advances in processing power to improve the quality of their VHF systems. For example, the Type 052D Luyang III destroyer features a Type 518 L-band radar paired with a conventional Type 346 AESA radar which could provide it with nascent anti-stealth capability against aircraft like the F-22 and F-35. At the present level of technological maturity, VHF systems would likely provide an early warning capability against stealth aircraft and could eventually cue X and S band systems which would provide the targeting information to surface to air missile systems. However, the weapon employment range of a VHF radar cued with a X and S band system may not be tactically significant. In the future, a system of VHF radars would be networked via a high speed datalink, the resolution cell could hypothetically be refined enough for a weapon quality track (Majumdar, 2014). Both the USAF and US Navy have made preparations to keep the F-35 relevant in highly contested VHF anti-access area denial (A2/AD) environments into the 2030s and beyond; as VHF systems continue to proliferate the use of electronic warfare in conjunction with low observable aircraft will become a necessity.

Another factor that has led to the development of a sixth generation fighter stems from China's cyber espionage activities. Edward Snowden recently released documents confirming China's role in stealing F-35 program information including the AN/APG-81 design, engine schematics, infrared signature reduction methods, etc. (Gady, 2015). These technical details have not only helped China build its own stealth aircraft, but also the information could be used to potentially facilitate the creation of countermeasures against the F-35. Lockheed Martin insists China has not managed to obtain the "crown jewels" or technical details that would effectively compromise the program. Despite Lockheed Martin's assurances, the data breach is generally regarded as a significant setback for the F-35 program. Chief of Naval Operations (CNO) Admiral Jonathan Greenert recently remarked, "The losing of proprietary data on high technology from cleared defense contractors — it’s just driving me crazy. Cyber theft is just hemorrhaging us". Ultimately, the Department of Defense's (DoD) decision to take the VHF threat seriously is prudent and essential towards maintaining the technological superiority of the American Military: 

senior officials are in the preliminary stages of examining options should stealth—one of the F-35’s key attributes—be compromised by new technology. The idea is to be able to hand off to the next presidential administration both a healthy F-35 program—no small feat, after its years of pitfalls and overruns—and other options should the next president find the aircraft’s technology outdated, the industry source says. The hope is the F-35’s technology will be viable for decades to come. The studies are preliminary and academic at this point, and they do not indicate the Pentagon is backing away from the F-35; its support has been unwavering since the 2011 restructuring. The Pentagon is now planning for a substantial ramp-up in production for the fighter over the next five years. - Amy Butler, 2015 

The emergence of a new threat during the development of a major fighter program is not new. The development of the sixth generation F-X while the fifth generation F-35 has yet to enter service is not dissimilar from how the Advance Tactical Fighter (ATF) program, which eventually led to the fifth generation F-22, was undertaken while the fourth generation F-X program - which led to the F-15A, had only just concluded. US reconnaissance satellites captured images of the T10-1 prototype, the Soviet's fourth generation response to the F-15 which resulted in the Su-27, in 1977 (Goebel, 2014). The Soviets had responded to the F-15 more quickly than anticipated and it was soon apparent that a new fighter aircraft was needed to maintain the US' technological advantage prompting the formulation of the ATF in 1981. Unlike the ATF during the 1980s, the next sixth generation aircraft(s) will be built by up to two of the remaining three US aerospace defense contractors that manufacture combat aircraft assuming the F/A-XX and F-X remain separate programs.

Image 3: Defense industry consolidation after the "last supper" in 1993. Image credit: Ann Markuson, 1998, “The Post-Cold War Persistence of Defense Spending,” in The Defense Industry in the Post-Cold War Era: Corporate Strategies and Public Policy Perspectives, ed G. I. Susman and S. O’Keefe (Amsterdam).

Image 4: Preliminary request for information concepts for the ATF courtesy of YF-23.net.

The consolidation of the US aerospace and defense industry after the Cold War has only been exacerbated in recent years due to the structuring of contemporary US combat aircraft procurement programs. Instead of a diverse set of multiple smaller procurement programs, there are only four major combat aircraft procurement programs over the next decade (UCLASS, T-X, LRS-B, and some F/A-XX and F-X work). Thus, if a major defense contractor fails to secure one of these programs it will be unable to sustain its aircraft manufacturing capability as the wait for another major program opportunity is unsustainable. Northrop Grumman is currently tenuously close to losing its aircraft manufacturing capability with its last combat aircraft manufactured in 1997 (B-2). Should Northrop Grumman lose both the upcoming Long Range Strike Bomber (LRS-B) and next generation trainer (T-X) programs, there is a strong possibility its aircraft division will be sold to either Lockheed Martin or Boeing which would reduce the competitiveness of future defense programs (Aboulafia, 2015). Part of the justification for accelerating the F-X and F/A-XX programs is to provide work for the defense industrial base such that further consolidation can be avoided (Sweetman, Asker, Norris, & Butler, 2015).

The last major reason for starting development of a sixth generation fighter, at least from the Air Force's perspective, is the limited number of high end air superiority platforms currently in service. F-22 production was prematurely terminated with 195 aircraft produced of which only 186 are in the Air Force's current inventory (e.g. not production representative test vehicles and engineering and manufacturing development aircraft). Of these 186 aircraft, only 123 to 149 are combat coded at any one time with the remainder of the aircraft serving in either in an attrition reserve, training, or test and evaluation role.  A total of 300 F-22As were to replace the existing F-15C/D fleet which will now receive an extensive series of upgrades to keep the Eagle fleet operational until at least the late 2020s. While the F-35 will provide robust air to air capabilities, it is not an air dominance fighter like the F-22. A new sixth generation fighter would greatly increase the service's air superiority capabilities upon the retirement of the F-15C/D and F-22A fleets. The USAF will require new sixth generation air superiority aircraft in the 2030s if the service seeks to retain the current disparity in projected kill ratios between Chinese or Russian and US fighters.

The DoD estimates the People's Liberation Army Air Force (PLAAF) will have its first operational J-20 unit between 2017 and 2018 (Sweetman, 2014). Similarly, the Russian Air Force will deploy its first fifth generation PAK FAs in 2016 with 55 units operational by 2020 (Novichkov, 2014). A new sixth generation air superiority fighter is needed  in the 2030s to hedge against a decline in expected US exchange ratios against increasingly advanced Russian and Chinese aircraft. A US Air Force official interviewed by the National Interest discussed the narrowing disparity in performance between US and Chinese aircraft which is a concern given China's regional numerical superiority:

I think we can probably keep a slight advantage for quite some time, but a slight advantage means significant losses and less of a deterrent...Lets pretend the F-22 confronts current air-to-air threats outside of a SAM [surface-to-air missile] environment and has a 30 to one kill ratio today versus a [Sukhoi] Su-30 or [Shenyang] J-11. When the J-20 and J-31 come around, even a three to one kill ratio advantage becomes costly...Our competitors know the current reality and are working very hard to avoid the wide gap we have created by investing in those planes,they represent their attempt and creating parity in the skies.

In an Australian Parliamentary hearing within the Foreign Affairs, Defense And Trade Joint Committee, Garry Liberson who is the Technical Lead of Operations Analysis and Strategic Studies at Lockheed Martin indicated the F-35 would have a six to one exchange ratio against "advanced red threats" in the 2015 to 2020 time frame (Source 69, page 5).The red threats described by Mr. Liberson are likely to be either upgraded Su-30s or Su-35s. Thus the author would surmise the F-35 would perform less favorably against the J-20 and Pak Fa when compared to the F-22 as discussed above. In order to the maintain its edge, the Air Force must inevitably invest in new platforms, upgrades for its existing platforms, and innovate new tactics techniques and procedures (TTP) with respect to its employment of those systems.

The A2/AD Strategic Environment of 2030

Image 5: Chinese A2/AD anti-surface warfare weapons in the Asia-Pacific. Image Credit: CSBA, 2014

It is important to emphasize the context in which American sixth generation aircraft will operate in conjunction with other American and allied aircraft rather than merely analyzing various tactical air to air combat scenarios between individual adversary and US platforms. The sixth generation development programs take place within the broader context of the third offset strategy and new concepts like distributed lethality all of which are geared towards mitigating advancements made by Russia and China to limit US power projection operations. To provide a brief overview, China began to develop systems to inhibit US power projection after the overwhelming victory of the United States in the Persian Gulf War:

...the consensus that U.S. forces were unbeatable in a conventional force-on-force conflict became the dominant global lesson learned. As the previous study notes [Conduct of the Persian Gulf War], 'while the Vietnam syndrome might always have been exaggerated and misinterpreted, the display of U.S. power in the Persian Gulf had the effect of creating an image of overwhelming power'. For nations, non-state actors, and other entities opposed to U.S. influence and contemplating violent means toward achieving their international political aims, conventional warfare seemed almost a closed option. - Tangredi, pg.29, 2013 

The general deterioration of Sino-US relations following Tienanmen Square in 1989, the Third Taiwanese Strait Crisis in 1996, and the US bombing of the Chinese embassy in Kosovo in 1999 all provided the impetus for China's development of its A2/AD strategy (Erikson, 2013). To constrain US power projection near its shores, China has implemented a host of systems including: sea mines, anti-ship cruise missiles (ASCMs), electronic &GPS jamming, submarines, anti-satellite weapons, conventional land attack and anti-ship ballistic missiles, and extensive surface to air missile systems networked with air power. These systems collectively limit how close US forces can safely operate in proximity to China and allow Chinese forces to avoid a conventional force on force engagement which favors US forces as described above. In order to further push US forces out of the region in wartime conditions, many Chinese source publications such as, The Science of Second Artillery Campaigns, emphasize the need to destroy US logistics assets in the Western Pacific which are the enablers of US power projection. These assets include aircraft carriers, ports, allied air bases, pre-positioned stockpiles (e.g. at Guam and Diego Garcia) tankers, etc. Note the explicit abstention from referring to the United States directly and the term "powerful enemy" is substituted for the United States instead (presumably for political reasons):

When the powerful enemy uses allied military bases in our periphery and aircraft carriers as aircraft launch platforms to implement various forums of military intervention; and when the powerful enemy's allied military bases around are periphery are beyond our air arm's firing range, and when the carrier battle groups are away from our shores, thus making it difficult to carryout out the overall operational advantages associated with firepower coordination among the service arms, conventional missiles can be used to implement harassment strikes against the military bases of the enemy's allies around our periphery as well as the carrier battle groups. - 401 (See source 55)

China's A2/AD strategy will force the US to operate its land and carrier based aircraft far from China's stores during the opening stages of the conflict. New technologies developed under the Defense Innovation Initiative and the National Aerospace Initiative will permit sixth generation aircraft to operate in in this heavy contested environment.

PART II - Development Status and Technology 
PART III - Roles and Missions
PART IV - Works Cited