China is integrating the two-seater J-20S, designed for electronic warfare and stealth drone control, into the Chinese Air Force.

On July 9, 2025, the Chinese Air Force (PLAAF) officially admitted the Chengdu J-20S, a two-seat version of the J-20, China’s fifth-generation fighter jet, into operational service. This variant, which has been observed in test flights since 2021, is intended for specific missions: electronic warfare, drone coordination, and complex tactical data processing. The second seat is not intended for training, but for advanced operational functions.

The arrival of the J-20S is part of a gradual transformation of Chinese combat aviation doctrine. China is no longer content with catching up with Western standards; it is seeking to offer architectures tailored to its technical constraints and strategic priorities. However, the addition of a second operator on board to manage systems that the US F-35 handles via centralized data fusion raises questions: does this design reflect an alternative tactical vision or a persistent limitation in networked sensor management?

The J-20S is intended, among other things, to coordinate Hongdu GJ-11 stealth drones in flight, which requires a robust command link. It could thus play a central role in Chinese collaborative combat schemes, which are still very different from Western CCA architectures. The entry into service of the J-20S provides a concrete assessment of the ambitions and limitations of China’s current military aviation program.

A two-seat fighter jet designed for electronic warfare and collaborative combat

Targeted structural modifications

The J-20S is based on the standard J-20 architecture, with a few structural modifications. The fuselage has been lengthened by nearly 70 centimeters to accommodate the second cockpit without altering the center of gravity or aerodynamic performance. The propulsion system remains unchanged: two WS-10C turbojet engines, pending a version equipped with the future WS-15 engines, which are still under development. The addition of the second seat required the partial relocation of the communication and electronic warfare systems to compact modules housed under the air intakes.

The rear cockpit is fully digitized, with a multifunction main display and redundant touchscreen interfaces. It allows the operator to access radar feeds, electronic warfare pod data, and transmissions from connected drones. This configuration is designed to relieve the pilot of tactical management and electronic warfare supervision tasks.

A specialized role in stealth drone coordination

The J-20S was designed to operate in an integrated manner with stealth drones such as the Hongdu GJ-11, which is also stealth, subsonic, flying wing, and optimized for deep strikes. The fighter jet then serves as an advanced command node, piloting several unmanned vehicles in a support or reconnaissance mission. This approach aims to saturate enemy defenses while limiting human exposure.

The link between the fighter jet and the drones is based on a secure data link, the operational range of which remains confidential. Experts estimate that a J-20S could coordinate 4 to 6 drones simultaneously, managing trajectories, identifying targets and possibly releasing weapons. This role requires high bandwidth and high onboard processing capacity, which justifies the separation of human roles on board.

A choice that reveals the limitations of Chinese network architecture

Distributed architecture instead of centralized processing

The use of a second operator illustrates a fundamental difference with US standards. The F-35A, for example, incorporates an automated sensor fusion system, where all data (AESA radar, optics, tactical link) is integrated and sorted by the mission computer. The pilot receives a synthetic, coherent image without having to manage each stream individually.

The J-20S, on the other hand, adopts a distributed architecture, where humans play an active role in sorting and exploiting information. This implies a higher cognitive load, offset by the addition of a second crew member. This choice probably reflects a technological limitation in the mastery of networked processing architectures, as well as in autonomous embedded software.

It should be noted that China has been developing data fusion algorithms since 2018, but integration remains partial. The use of the J-20S could therefore be a transitional solution, intended to compensate for the software lag with a human solution.

A doctrine still focused on direct human control

Western doctrine is moving towards controlled autonomy, where unmanned systems operate with little human intervention thanks to tactical AI. Conversely, the PLAAF continues to favor direct human control, even in complex missions. This is reflected in platforms such as the J-20S, but also in the absence of autonomous initiatives at the drone swarm level.

This approach avoids the risks of algorithmic drift, but at the cost of slower responsiveness and increased exposure of piloted assets. While a second crew member is essential to pilot a group of drones, this severely limits the scale of simultaneous deployment of these swarms, unlike the US CCA (Collaborative Combat Aircraft) program, which is based on automation.

Operational entry into service fraught with strategic challenges

Gradual entry into service in specific units

The J-20S has been integrated into the Wuhu Air Base, in a unit specializing in deep air-to-ground missions and electronic warfare. The initial volume is expected to be six aircraft delivered, with a ramp-up to 24 units by 2026. The estimated cost per unit is around €110 million, taking into account the specific architecture and integration of C2 (Command and Control) systems.

The commissioning schedule includes a 12-month operational testing phase, during which crews will test the limits of the man-drone system in real conditions. Joint exercises with S-400 batteries and GJ-11 drones are planned to validate engagement doctrines. China is thus seeking to build a coherent air-ground force capable of penetrating multi-layered defenses in the Asia-Pacific region.

A response to US and Japanese technological acceleration

The introduction of the J-20S comes as the US is finalizing the first flight tests of the NGAD (Next Generation Air Dominance), a sixth-generation stealth aircraft designed to interact with multiple autonomous drones. Japan and South Korea are also investing in collaborative platforms and disruptive air-to-ground weapons. Beijing is now obliged to offer a credible alternative, even if its solutions remain more human than software-based.

The deployment of the J-20S confirms that China is seeking to master networked combat, but via an intermediate paradigm, pending a transition to full automation. This hybrid model, which is still dependent on the human factor, is likely to be less flexible on a large scale, particularly in high-intensity conflicts where command centers are targeted from the outset.

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