Future Chinese Carrier Air Wing Composition Gradually Comes into Focus

At the start of 2024, China’s first catapult-assisted take-off barrier arrested recovery (CATOBAR) aircraft carrier, the Type 003-class hull Fujian, was in an advanced state of construction and heading toward sea trials, moving China closer to a fleet of three operational aircraft carriers following some two decades of concerted effort. While a growing number of data points suggested that Fujian would host a new low-observable crewed CATOBAR fighter aircraft reportedly designated the J-35, much was uncertain about the trajectory of Chinese carrier-based naval aviation at the start of the year. A series of developments over 2024, however, have brought the future composition of China’s carrier air wings into greater focus. This SPAS Consulting analysis examines recent developments in China's fixed-wing carrier-borne crewed combat aircraft fleet.

Recent Developments in China's Fixed-Wing Carrier-Borne Crewed Combat Aircraft Fleet

In February 2024, undated images circulating on Chinese social media indicated the presence of an apparent mockup of the new low-observable J-35 fighter aircraft on the short take-off barrier arrested recovery (STOBAR) aircraft carrier Liaoning. This was a major unexpected development as the J-35 was hitherto understood to be a CATOBAR aircraft design intended for use on Fujian, China’s first CATOBAR aircraft carrier, while Liaoning is a STOBAR aircraft carrier (as is China’s second aircraft carrier Shandong). There were two primary ways to interpret this unexpected development. The first interpretation was that the Chinese Navy planned to procure a previously unknown STOBAR version of the J-35. If this were the case, the Chinese Navy would not only be potentially transitioning away from the STOBAR J-15 design but also committing itself to the operation of two mutually interoperable fleets of the new J-35 aircraft design respectively restricted to its two existing STOBAR aircraft carriers (Liaoning and Shandong) and its forthcoming CATOBAR aircraft carriers (Fujian and any other CATOBAR aircraft carriers that China may construct and commission at a future date). The second interpretation was that the Chinese Navy planned to also operate a CATOBAR fighter aircraft, seemingly a CATOBAR J-35, and perhaps other CATOBAR aircraft, on its two existing STOBAR aircraft carriers (in a necessarily degraded capacity given the restrictions on maximum take-off weight imposed by the use of a ski-jump). If this were the case, the Chinese Navy would be seemingly positioning itself to deploy a single more or less interoperable fleet of carrier-borne crewed fighter aircraft (and accompanying aircrew) that can be assigned to STOBAR and CATOBAR aircraft carriers as required.

At the time that these images of a J-35 mockup on the deck of Liaoning were circulated online, publicly available information did not offer clarity as to which of these two interpretations was accurate. The unexpected appearance of a J-35 mockup on the STOBAR Liaoning raised therefore questions about the future of both the STOBAR J-15 fighter aircraft and its CATOBAR version, the J-15T, in Chinese Naval Aviation. Was the STOBAR J-15 merely an interim aircraft for use in training with China’s two operational STOBAR aircraft carriers until either CATOBAR or possibly STOBAR J-35 aircraft became available for use with Liaoning and Shandong? Did the Chinese Navy plan to operate the CATOBAR J-15T for purposes beyond training on the forthcoming CATOBAR aircraft carrier Fujian or had it fully committed to the J-35? Did the unexpected appearance of a CATOBAR J-35 mockup on the deck of Liaoning indicate that the Chinese Navy also planned to operate CATOBAR J-15T aircraft on the STOBAR aircraft carriers Liaoning and Shandong? If the CATOBAR J-15T, which reportedly had its first flight in 2016, still had a future in Chinese Naval Aviation alongside the new J-35, which reportedly had its first flight in 2021, had the Chinese Navy committed the requisite resources toward the very expensive parallel procurement of two naval fighter aircraft designs that are unlikely to have any other operator, whether domestic or foreign?

The preparation of China’s first CATOBAR aircraft carrier Fujian for sea trials in early 2024 offered a steady stream of additional information for observers interested in the future composition of Chinese carrier air wings to digest. In March 2024, undated images circulating on Chinese social media indicated the presence of several mockups on the deck of Fujian. The mockups included not just a necessarily CATOBAR (in the absence of a ski-jump on the Fujian) J-35, which was expected, but also a necessarily CATOBAR J-15T and, no less importantly, a necessarily CATOBAR JL-10 training aircraft. Undated images circulating online also indicated the presence of a mockup of the new KJ-600 turboprop-driven necessarily CATOBAR AEW&C aircraft on the deck of Fujian. These images offered observers their best glimpse to date into the likely composition of the CATOBAR aircraft carrier Fujian’s air wing at the time it will enter service (Fujian continues to undertake sea trials as of this writing in November 2024).

The presence of a mockup of the CATOBAR J-15T on Fujian was particularly notable as it suggested that the Chinese Navy planned to operate this existing fighter aircraft design on its new CATOBAR aircraft carrier alongside the new low-observable J-35 fighter. This data point, in turn, not only supported the interpretation that the earlier presence of a mockup of J-35 on the STOBAR aircraft carrier Liaoning reflected the Chinese Navy’s plans to operate CATOBAR aircraft from its STOBAR aircraft carriers, but also suggested that the CATOBAR J-15T may feature on China’s STOBAR aircraft carriers. If this was the case, these data points collectively suggested that the Chinese Navy was setting itself up to establish several units of carrier-borne crewed fighter aircraft that could be interoperable on any of China’s new and forthcoming aircraft carriers (albeit in a necessarily degraded capacity on STOBAR carriers given the restrictions on maximum take-off weight imposed by the use of a ski-jump).

While a steady release of undated images on Chinese social media occasionally amounted to noteworthy data points, observers would have to wait several months for a development with major analytical implications. In late October 2024, China undertook its first known exercise involving both of its operational STOBAR aircraft carriers. The images and videos released by the Chinese Navy offered observers a rare glimpse into the operational practices of China's aircraft carriers and carrier-borne aircraft. Most importantly, the images and videos released by the Chinese Navy confirmed that China’s two operational STOBAR aircraft carriers were hosting a combination of STOBAR J-15 and CATOBAR J-15T fighter aircraft, which is to say that these images and videos confirmed that the J-15T was in service and suggested that the Chinese Navy planned to operate CATOBAR J-15T fighter aircraft on its two STOBAR aircraft carriers.

Uncertainties About the Future of China’s Two Operational STOBAR Aircraft Carriers

Although the media released by the Chinese Navy of its first exercise involving two aircraft carriers amounts to important datapoints, uncertainties endure about the future of China’s two operational (STOBAR) aircraft carriers and the composition of their air wings. It is possible that CATOBAR J-15T aircraft have been deployed on China’s two operational STOBAR carriers as an expedient measure to expedite the training of pilots and air crews in the lead-up to the commissioning of China’s first CATOBAR aircraft carrier Fujian. China will, after all, need more carrier-qualified pilots than required for its two (much smaller) operational STOBAR carriers when Fujian is commissioned or at least one of the two STOBAR carriers may functionally lose its air wing (in terms of transferred personnel) to Fujian at least temporarily. If this is the case, then CATOBAR J-15T aircraft may not be a permanent fixture on the STOBAR Liaoning and Shandong – these aircraft carriers may be limited to STOBAR J-15 aircraft once Fujian enters service.

While the exigency of preparing an air wing for Fujian is likely to be an important factor shaping the decisions made by the Chinese Navy, it is also important to recognize that early production STOBAR J-15 aircraft, which have been operating off of Liaoning since 2012, have likely been subjected to considerable wear and structural fatigue following extensive use in both shore- and sea-based training activity over the past twelve or so years. This dynamic has likely been compounded by the ongoing absence of an operational jet trainer aircraft that can both take off and land on China’s two operational STOBAR aircraft carriers (if and when it is deployed on aircraft carriers, the JL-10 training aircraft will allow the Chinese Navy to belatedly address this glaring capability gap).

Early production STOBAR J-15 aircraft – and possibly all STOBAR J-15 aircraft produced to date – also appear to be equipped with outdated – by current Chinese standards – avionics and accompanying armament. It is therefore possible that the Chinese Navy has decided to progressively replace older STOBAR J-15 airframes with new CATOBAR J-15T airframes, which can evidently operate on both STOBAR and CATOBAR aircraft carriers, instead of ordering additional (likely upgraded) new-build STOBAR J-15 airframes or upgrading what are likely to be worn-out early production STOBAR J-15 airframes. If this is the case, then newer in-service STOBAR J-15 airframes may eventually be consolidated into one unit or, alternatively, the two existing air wings for the STOBAR Liaoning and Shandong may become hybrid units operating some combination of STOBAR J-15 and CATOBAR J-15T aircraft. There is some precedent for such a practice in the Chinese Air Force – many Chinese Air Force brigades (suboptimal) operate two or more types of similar but not identical aircraft as an expedient way to round out numbers and support training requirements (with two-seat aircraft) – and Chinese Naval Aviation may do the same for as long as a subset of its STOBAR J-15 fleet remains serviceable.

Given the forthcoming commissioning of China’s first CATOBAR aircraft carrier Fujian and reports of underway efforts to develop a nuclear-powered CATOBAR aircraft carrier, the analytical emphasis given here to China’s two operational STOBAR aircraft carriers may appear surprising. It is, however, important to recognize that whatever the inherent limitations of STOBAR aircraft carriers, Shandong was only commissioned in 2019 and was built in China (i.e., it is not a Soviet-built hull unlike the older Liaoning). It is therefore reasonable to assume that Shandong will remain in service for several decades – perhaps into the 2050s – unless the Chinese Navy decides to retire it at an earlier date for one reason or another.

The situation with Liaoning, which was commissioned in 2012, is more complex because its hull was designed and built in the Soviet Union. Originally set to be commissioned in the Soviet navy as the Varyag, Liaoning’s hull was launched in 1988 and remained incomplete following the dissolution of the Soviet Union. Acquired by a Chinese businessman with the declared objective of converting the incomplete Varyag hull into a floating casino – the realized fate of two other ex-Soviet aircraft carriers that also ended up in China – the Varyag arrived in China under tow in 2002 and entered a drydock in Dalian in 2005. After seven years of extensive work to, in effect, complete, refurbish, and no less, modify and upgrade the incomplete Soviet-built STOBAR aircraft carrier, the heavily modified Varyag hull entered the service of the Chinese Navy as Liaoning in 2012. This complex history notwithstanding, the Chinese Navy, an organization that has to date hesitantly decommissioned operable systems even when much more capable replacements were available, will likely attempt to derive at least two decades of service from Liaoning, meaning that China’s first operational aircraft carrier will likely remain in service well into the 2030s in the absence of major serviceability issues or major budgetary restrictions.

Whatever the projected and realized service lives of the mostly Soviet-built Liaoning and the Chinese-built Shandong, these two STOBAR aircraft carriers have been completed and operated at great expense – each aircraft carrier has a crew – including the air wing – of several thousand personnel – and, of course, require competitive fixed-wing combat aircraft for their respective air wings. The use of CATOBAR aircraft, whether the J-35 or the J-15T, on these STOBAR aircraft carriers, even in a degraded capacity given the restrictions on maximum take-off weight imposed by the use of a ski-jump, offers Liaoning and Shandong an extended lease of life and does so in a way that will allow the Chinese Navy to more efficiently allocate its immense and ever expanding but nevertheless finite budget. The Chinese Navy appears to have no interest in retaining its STOBAR aircraft carriers with what amount to orphan STOBAR air wings at great expense. Given the apparent limitations of the earliest STOBAR J-15 airframes in terms of avionics and armament, new CATOBAR J-15T and J-35 aircraft also offer a substantial upgrade in air combat capabilities that the Chinese Navy desperately needs given the fast-evolving military environment in the Western Pacific.

The Conspicuous Absence of Two-Seat STOBAR and CATOBAR Aircraft

The STOBAR J-15 and CATOBAR J-15T are both single-seat aircraft – as is the only known version of the new J-35 – and this has major implications, not least in terms of the capacity of the Chinese Navy to establish and sustain the large pool of carrier-qualified pilots required to operate the much larger Type 003-class aircraft carrier Fujian (currently undergoing sea trials) alongside China’s two operational STOBAR aircraft carriers Liaoning and Shandong. The existence of a two-seat version of the STOBAR J-15, the STOBAR J-15S, was reported as early as 2012, the year in which the J-15S reportedly had its first flight, but the J-15S does not appear to have been produced in large numbers over the past twelve years for unknown reasons. Two-seat versions of single-seat fighter aircraft are significantly heavier, and it is possible that the Chinese Navy has not been interested in procuring a large number of two-seat STOBAR J-15S aircraft given the restrictions on maximum take-off weight imposed by the use of a ski-jump, not least for an aircraft with the very high empty weight of the STOBAR J-15 and J-15S.

In the absence of a discernibly sizeable fleet of two-seat STOBAR J-15S aircraft and in the not unrelated absence to date of an operational jet trainer that can both take off and land on China’s two operational STOBAR aircraft carriers, the Chinese Navy has primarily trained its pilots on single-seat STOBAR J-15 aircraft, which is decidedly suboptimal (China consequently appears to rely heavily on computer simulators and the use of land-based jet trainers that can take-off from a land-based ski-jump but lack an arresting gear for training at a terrestrial airbase). Should a CATOBAR J-15ST – this is a speculative designation – be developed, the Chinese Navy will likely operate these in larger numbers on its CATOBAR aircraft carriers alongside CATOBAR J-15T aircraft at least for training purposes.

While the very high empty weight of the underlying STOBAR J-15 design makes it poorly suited for operations from STOBAR aircraft carriers, a high empty and maximum take-off weight is less of a concern on the CATOBAR aircraft carriers like Fujian. It is worth noting that, as of this writing, the new low-observable J-35 is only known to exist in a single-seat version, and this will have implications for how the Chinese Navy will train J-35 pilots. The Chinese Air Force encountered the same challenge when it deployed the single-seat J-20 and eventually oversaw the development of the two-seat J-20S with the likely objective of enhancing training and, no less importantly, incorporating a weapons systems operator in the second seat who can oversee if not control uncrewed fixed-wing aircraft operating alongside a J-20S. It is possible that the Chinese Navy will eventually pursue a two-seat version of the J-35 for similar reasons and that Fujian and future Chinese CATOBAR carriers will operate both CATOBAR J-15ST and J-35S – this is a speculative designation – two-seat fighter aircraft.

Beyond the standard use of two-seat aircraft in training roles, the second seat in a J-15ST (or a J-35S) can be used to accommodate a mission commander, which can add to operational flexibility and combat effectiveness. The second seat in a J-15ST can, as previously alluded to in the context of the land-based J-20 fighter, also offer a practical interim approach to integrating uncrewed fixed-wing aircraft in the air wings of China’s CATOBAR aircraft carriers. While many two-seat versions of fighter aircraft have historically been built as downgraded trainers lacking in expensive avionics as a cost-cutting measure, the two-seat versions of fighter aircraft are increasingly built in a configuration that are no less capable in terms of avionics and armament than their single-seat counterpart. It is therefore possible that a J-15ST may be a combat-capable trainer that can be readily integrated into carrier air wings deployed at sea. There is also a possibility that the Chinese Navy will emulate the Chinese Air Force, which made the notable decision to terminate production of the increasingly outdated single-seat J-11B fighter and forgo procurement of its far more capable upgraded derivative and natural replacement, the single-seat J-11D multirole fighter. The Chinese Air Force instead fully committed itself to the production of the two-seat J-16 which is, in effect, a heavily modified two-seat J-11BS with avionics in line with the J-11D. It remains to be seen whether the Chinese Navy will place similar value on having the option of placing a weapons system operator in the rear seat that can reduce the pilot’s workload and undertake other mission-critical roles.

While the two-seat STOBAR J-15S does not appear to have been built in significant numbers to date, its development nevertheless enabled the development of another important two-seat version of the underlying J-15 airframe, the STOBAR J-15D, in which the Chinese Navy has exhibited much greater interest. The J-15D is a two-seat STOBAR electronic warfare aircraft analogous to the American EA-18G, which is the electronic warfare version of the two-seat F/A-18F multirole fighter operated by the United States Navy. Like its American analogue, the J-15D is a heavily modified version of its parent airframe. The Chinese J-15D and American EA-18G are stripped of gun-type armament, have certain electronic warfare systems integrated into the airframe and installed on the wingtips, are fitted with enhanced avionics, and are wired to employ wing-mounted multiple pods containing bespoke electronic warfare equipment including jammers that are not fitted onto the standard versions of their respective parent aircraft designs. The Chinese J-15D and American EA-18G are, in other words, very expensive to develop, build, and sustain high-end combat aircraft optimized for a very important but very niche role.

The STOBAR J-15D electronic warfare aircraft is reported to have first flown in 2015. China’s first aircraft carrier, Liaoning, was only commissioned in 2012, and the strikingly early development of the J-15D amounted to one of the earliest indications that the Chinese Navy had grand ambitions – in both qualitative and quantitative terms – when it came to its aircraft carriers. While electronic warfare aircraft like the Chinese J-15D and American EA-18G can still be used in air-to-air combat roles, these are primarily designed to suppress the air defences of land-based air defence systems and naval air defences. The very existence of the J-15D, in other words, indicated that the Chinese Navy neither intended to have a token aircraft carrier force nor one in which carrier air wings were largely restricted to air-to-air combat roles.

Although the very development of the STOBAR J-15D at such an early date heralded the grand ambitions that decision-makers in Beijing had for Chinese carrier-borne naval aviation, this two-seat version of the STOBAR J-15 airframe also does not appear to have been produced in significant numbers over the past decade or so. A STOBAR J-15D did, however, make an unexpected appearance at the 2024 iteration of the China International Aviation & Aerospace Exhibition, also known as the Zhuhai Airshow, and this appearance appears to amount to confirmation that the J-15D is operational in the service of the Chinese Navy. The appearance of a J-15D at the 2024 iteration of the Zhuhai Airshow notably follows the unexpected and high-profile appearance of the Chinese Air Force’s analogue to the J-15D, the J-16D, which is the electronic warfare version of the two-seat J-16 multirole fighter, at the 2022 iteration of the Zhuhai Airshow.

While the Chinese Navy’s J-15D and the Chinese Air Force’s J-16D likely share at least some core electronic warfare systems, it is important to recognize that the J-16D and its parent J-16 airframe are substantially different from the J-15D and its parent J-15 airframe in multiple respects beyond the aspects of the J-15 airframe that are reflective of adaptations required to take off from and land on an aircraft carrier in a STOBAR let alone a more demanding CATOBAR configuration. The J-15D and J-16D are, as such, best viewed as entirely distinct aircraft undertaking much the same role. Insofar as the J-15D and J-16D share core electronic warfare systems, however, it stands to reason that the apparent small-scale deployment of the STOBAR J-15D by the Chinese Navy is best explained by factors other than the immaturity of the electronic warfare systems for operational status or else the J-16D would presumably not have been operational in the service of the Chinese Air Force as early as 2022.

Although the apparent small-scale deployment of the STOBAR J-15D electronic warfare as of this writing may be explained by something as mundane as budgetary limitations, other data points, not least the unexpected deployment of the CATOBAR J-15T on China’s two operational STOBAR aircraft carriers and the appearance of CATOBAR J-15T mockup on the flight deck of China’s latest (CATOBAR) aircraft carrier Fujian, raises the possibility that the Chinese Navy may be forgoing full-rate production of the STOBAR J-15D pending the availability of a CATOBAR J-15DT version (this is a speculative designation). If the Chinese Navy is indeed committed to deploying and sustaining a single more or less interoperable fleet of CATOBAR carrier-borne crewed fighter aircraft that can be assigned to both STOBAR and CATOBAR aircraft carriers as required, the Chinese Navy will have little reason to procure large numbers of what are likely to be very expensive STOBAR J-15D aircraft that can never operate from CATOBAR Fujian or any future Chinese CATOBAR aircraft carrier.

Beyond the possibility that budgetary allocations have prioritized production of the J-15T over a notional J-15DT, the establishment of an airwing for China’s first CATOBAR aircraft carrier Fujian, which requires both suitable airframes and fully trained air and ground crews, is likely to be a top priority for the Chinese Navy. The Shenyang Aircraft Corporation (SAC) is responsible for the production of the J-16, which is exclusively operated by the Chinese Air Force, and both the STOBAR J-15 and CATOBAR J-15T operated by the Chinese Navy. SAC is also responsible for producing the J-35 for the Chinese Navy and, no less, the J-35A, the land-based derivative of the J-35 intended for the Chinese Air Force which has notably also featured in the 2024 Zhuhai Airshow. While SAC’s production facility has been subject to extensive construction activity in recent years with the aim of expanding production capacity, production slots are not only finite but must be allocated to both the Chinese Air Force and the Chinese Navy. It is, therefore, possible that the Chinese Navy has prioritized the production slots allocated to it toward the production of the single-seat CATOBAR J-15T in the lead-up to the commissioning of Fujian and that two-seat J-15DT and perhaps J-15ST will be built at a later date.