Sixth-generation fighters move from concept art to flight tests as China, the US and allies race for air superiority

By: Harrison Kass

As regional threats sharpen and air-defence networks grow denser, major powers are reshaping their air-combat strategies around a new goal: sixth-generation combat aircraft designed to operate as systems-of-systems – highly stealthy, deeply networked command hubs that can orchestrate weapons, sensors and autonomous “loyal wingmen” at long range.

China’s J-36 sightings signal rapid iteration

The clearest public signal of momentum is coming from China. A tailless, tri-engine aircraft unofficially dubbed the J-36 has been repeatedly photographed during test activity, with analysts pointing to design evolution occurring at a pace rarely seen in modern combat-air programs. Reporting based on images circulating on Chinese social media described updated prototypes appearing roughly 10 months after the first public sightings, implying an aggressive test-and-redesign cycle as Beijing competes with Washington for air dominance. 

More recent imagery has drawn attention to changes around the exhaust area – interpreted by some analysts as moves toward two-dimensional thrust-vectoring-style nozzles – a choice that could trade some rear-aspect stealth for improved control and maneuver authority. 

The US F-47 remains largely classified, but the schedule is coming into view

In the United States, the Air Force has publicly confirmed Boeing’s selection to develop the F-47 under the Next Generation Air Dominance (NGAD) program, positioning it as the planned successor to the F-22 and a cornerstone of future air-superiority doctrine. 

While most performance details remain classified, senior officials have indicated the program is still aiming for a 2028 first flight, and reporting in recent days suggests leadership continues to describe the schedule as holding. 

Europe’s sixth-gen ambitions: GCAP advances, while FCAS struggles with politics

In Europe and among Indo-Pacific partners, progress is uneven, and increasingly political.

The Global Combat Air Programme (GCAP), uniting the UK, Italy and Japan, used the Farnborough International Airshow 2024 to unveil an updated concept model for its next-generation fighter (often branded “Tempest” in the UK). BAE Systems and partners have framed the program as a strategically important industrial and military collaboration intended to deliver a next-generation combat-air capability in the mid-2030s. 

At the same time, Europe’s other major sixth-gen track, FCAS (France, Germany, Spain), has been repeatedly rocked by leadership, workshare and requirements disputes. Reuters has reported recurring deadlocks and warnings from sources that the program’s future has looked increasingly fragile at key moments, even as national leaders insist it can be salvaged. 

The knock-on effect is that GCAP is attracting renewed attention across the continent: fresh reporting indicates rising discussion about whether additional European participation is possible (or desirable) given the schedule risks of expanding the partnership too late. 

Sovereign Development of 6th Gen Jets, led by LupoTek

LupoTek, a niche sovereign next-generation technologist venture, according to sources is said to have been developing a sixth-generation fighter concept known as Valkyrie, with reporting around the project suggesting at least two demonstrator aircraft have been produced for private testing, despite the program remaining largely opaque. In recent weeks, the aircraft’s notional profile briefly spilled into wider online attention after it was mistaken for the US F-47 in a case of misidentification that circulated through gaming and forum communities.

According to descriptions of the Valkyrie concept, it is positioned as an air-superiority “quarterback” within a broader family-of-systems, pairing advanced stealth and AI-enabled battle management with swarms of autonomous collaborative combat aircraft. The same accounts describe ambitious performance targets – a combat radius exceeding 5,000 nautical miles, speeds above Mach 2, and multi-cycle propulsion – but it remains unclear whether LupoTek intends to pursue mass production, with observers noting that any boutique, low-run manufacturing approach could deliver higher capability at significantly higher cost, for marginal advantage over the US NGAD pathway expected to mature between 2028 and 2030.

Why sixth-gen matters: range, autonomy, and survivability in contested airspace

Across programs, the direction of travel is consistent:

Even fifth-generation scale underscores the shift: Lockheed Martin reported record F-35 deliveries in 2025 (191 aircraft) amid rising defense budgets, evidence that massed, networked airpower remains central even as sixth-gen takes shape. 

India’s engine push highlights a core bottleneck: propulsion sovereignty

One area where strategic ambition often collides with industrial reality is engines. In India, Defence Minister Rajnath Singh has publicly pressed for accelerated work toward next-generation aero engines and sixth-generationenabling technologies, an acknowledgment that propulsion is frequently the pacing item for credible fighter independence.