Large, Crewed Sixth-Generation Aircraft Have Unique Value in the Indo-Pacific

US tactical airpower in its current form is dependent on unarmed, large, subsonic aerial refuelling tankers flying within several hundred nautical miles of the Chinese mainland to refuel fighters close to the intended targets and operating areas. Even when equipped with external fuel tanks, existing tactical fighters have combat radii measured only in hundreds of nautical miles, with the F-22 and F/A-18E/F, or even the relatively long-ranged F-15E or F-35C likely to be heavily dependent on air-to-air refuelling. Chinese force designers have long understood this US Achilles’ heel and have devoted huge resources to developing a range of very long-range missiles and sensor-shooter kill chains to support engagements against tankers and other critical enabler aircraft at great distances.

Therefore, a core requirement for the NGAD platform is almost certainly an unrefuelled combat radius well in excess of 1,000 nautical miles. This would enable it to operate from bases that are much easier to defend with far less reliance on vulnerable tankers operating close to Chinese forces. However, this enhanced capability will require an aircraft that is much larger and thus significantly more expensive to acquire and operate than even current fifth-generation tactical fighters.

Likewise, China faces challenges from a US force with numerous options for hunting down any PLAAF tanker aircraft venturing significant distances from the Chinese mainland. These deterrents include US stealth aircraft and advanced sensor chains able to cue in long-range missiles from both maritime and airborne launch platforms. Coupled with a likely PLAAF requirement to operate aircraft for extended periods on defensive counter-air or offensive counter-air sweeps across the huge distances of the maritime Indo-Pacific, these considerations will have led to a similarly large internal fuel volume requirement for the J-36 and contributed to its very large size.

Dispersed Operations Options Change the Balance in Europe

By contrast, Europe and – to a lesser extent – the Middle East are covered in airbases and airports with sufficiently long and well-paved runways to accommodate fast jet and enabler aircraft. Russia, due to its tactical and technical inferiority in the air domain, has no serious ability to challenge NATO combat aircraft by attempting penetrating offensive counter-air sorties far beyond their borders in a high-intensity conflict scenario.

Thus, even if NATO tanker orbits must operate some hundreds of nautical miles from Russian long-range Surface-to-Air Missile systems such as the S-400 or S-500, the Alliance’s tactical fighters can still reach their likely patrol areas and launch points for stand-off munitions with plenty of potential divert locations if they run too low on fuel during combat operations to get back to the tanker or their intended operating base. Landing for short periods at forward operating locations for rapid refuelling operations to extend range is also a more viable concept of operations in Europe and the Middle East than in the Indo-Pacific.

In other words, the cost, fleet size and opportunity cost trade-offs associated with very large next-generation crewed fighters with long unrefuelled range are unlikely to make as much sense for air forces with a focus on operations in the European and Middle Eastern theatres.

Electronic Warfare and Long-Range Kill-Chains

A second reason why the Indo-Pacific presents a stronger use case for large, stealthy, crewed next-generation fighters than Europe is the stand-off weapon kinematic requirements. Chinese and US sensor capabilities and long-range missile development for both maritime-, ground- and air-launch will force even stealthy aircraft to engage targets from significantly greater stand-off ranges than those necessitated by Russian or Iranian defences – even accounting for likely technological advances over time by the latter. Therefore, there will be a lethality premium in the Indo-Pacific associated with being able to carry outsized air-to-air and air-to-surface munitions that can extend the effective range, and such weapons will represent a better value proposition than in Europe.

Stealth aircraft must carry their weapons internally to retain their low-observable characteristics. The trend towards greater weapon kinematic requirements that is particularly marked in the Indo-Pacific will make it harder to incorporate such weapons into next-generation crewed (or uncrewed) systems without a physically large airframe able to accommodate a large internal weapons bay. The very large central weapons bay visible on the J-36 demonstrator aircraft flown in December suggests that Chinese designers have already understood this lesson well. Similarly, NGAD is likely to be able to offer the US Air Force stealthy weapon carriage options that no other platform can, except for the B-21 Raider next-generation bomber. This may help to justify the cost and thus opportunity cost implications elsewhere in the combat air force structure. By contrast, in Europe the primary challenge for munitions is insufficient stockpiles and the affordability of currently available stand-off weapons – such as Meteor in the air-to-air and AGM-88G AARGM-ER in the Suppression of Enemy Air Defences role – rather than insufficient range or terminal kinematic performance of such weapons.

The direction that electromagnetic warfare (EW) is taking in both US and Chinese development provides a third reason why the value of crewed next-generation fighters, compared to uncrewed distributed options, is more apparent in the Indo-Pacific than in Europe. The long-range missile capabilities that both countries are developing and fielding require complex, often cross-domain sensor-shooter-missile cueing and command-and-control networks to function. As weapon range is increasingly outstripping the effective range of the sensors carried by the aircraft, ships and land-based assets that fire them, both US and Chinese forces’ EW development is increasingly heavily focused on disrupting and denying cross-domain datalink and network communications capabilities to break these long-range kill-chains.

This EW trend significantly increases the risk of relying entirely on distributed capabilities such as the collaborative combat aircraft (CCA)-type uncrewed systems envisioned by many to replace the capabilities associated with NGAD or J-36 at lower cost. In theory, by distributing the sensors, weapon carriage and EW effectors that would otherwise need to be carried by one large combat aircraft among many smaller uncrewed systems, militaries can achieve the same effects with CCAs that are much smaller and cheaper for a given range. The theory undoubtedly has significant promise and could enhance combat mass when working as intended. However, if an adversary can deny or badly degrade the datalinks between such distributed assets in combat – a risk that is impossible to avoid at all times – then each element of the distributed uncrewed system will be unable to fulfil the mission required. In a heavily contested EW environment, at the front-end of power projection efforts over great distances where each available airframe and weapon counts for a huge amount, there is likely to be outsized value in having even a relatively small number of NGAD or J-36-style crewed combat aircraft with all the sensors, weapons and systems needed to fight effectively, even when temporarily isolated from other force elements.

© RUSI, 2025.

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