SOURCE: AFI
As the race to develop sixth-generation fighter jets accelerates, manufacturers and developers remain tight-lipped about the specifics that set these advanced platforms apart from their fifth-generation predecessors. Unlike the well-documented capabilities of fifth-generation jets like the Lockheed Martin F-22 Raptor, F-35 Lightning II, Russia’s Su-57, and China’s J-20, the details of sixth-generation designs are shrouded in secrecy, often cloaked under classified programs or vague press releases.
Yet, recent observations from prototype unveilings, industry hints, and expert analyses suggest a clear evolution in design and performance. Here’s what sets sixth-generation fighters apart from their fifth-generation counterparts, based on emerging trends and informed speculation.
1. Expanded Internal Weapons Bay (IWB) Capacity
One of the most striking differences lies in the internal weapons bay (IWB) capacity, a critical factor for maintaining stealth while delivering lethal payloads. Fifth-generation jets, such as the F-22 (capable of carrying 6 AMRAAMs and 2 Sidewinders) and F-35 (4 internal missiles in stealth mode), prioritize radar-evading profiles by housing weapons internally. Sixth-generation designs appear to take this further. The UK-led Global Combat Air Programme (GCAP), for instance, is rumored to boast an IWB capable of holding 10 beyond-visual-range (BVR) missiles plus 2 close-combat missiles (CCMs). Similarly, China’s Shenyang J-50 prototype, spotted in late 2024, features a 7.25-meter-long IWB—suggesting space for larger or more numerous munitions, potentially including hypersonic weapons. This leap in capacity reflects a shift toward greater firepower without compromising stealth.
2. High Maximum Takeoff Weight (MTOW)
Sixth-generation fighters are trending toward larger, heavier airframes to accommodate advanced systems and extended missions. While fifth-generation jets like the F-22 (MTOW of 83,500 lbs) and J-20 (estimated MTOW of 80,000 lbs) are sizable, emerging sixth-generation designs hint at even higher MTOWs. The Boeing F-47, selected for the U.S. Next Generation Air Dominance (NGAD) program in March 2025, and China’s Chengdu J-36, which flew in December 2024, are speculated to exceed 100,000 lbs. This increase supports larger fuel loads, bigger IWBs, and enhanced avionics, enabling these jets to tackle the vast distances of modern theaters like the Indo-Pacific.
3. Increased Range
Range has emerged as a defining feature of sixth-generation fighters, addressing the strategic demands of sprawling battlefields. Fifth-generation jets offer impressive but limited ranges—around 600 nautical miles for the F-22 (with external tanks) and 1,200 nautical miles for the F-35A. In contrast, sixth-generation designs prioritize extended reach. The J-36’s trijet configuration and the F-47’s adaptive cycle engines suggest ranges potentially exceeding 2,000 nautical miles, unrefueled. This capability, paired with larger fuel capacities, positions these jets as long-range strike platforms, capable of projecting power deep into contested zones without relying heavily on tankers.
4. More Power Generation
The energy demands of next-generation systems—AI, directed-energy weapons (DEWs), and advanced sensors—require a quantum leap in onboard power generation. Fifth-generation fighters rely on engines like the Pratt & Whitney F119 (F-22), generating around 150-200 kilowatts. Sixth-generation jets, however, are expected to integrate variable-cycle or low-bypass engines producing upwards of 500 kilowatts. This surge in power supports DEWs like lasers for missile defense, extensive electronic warfare suites, and real-time data processing for manned-unmanned teaming (MUM-T), where fighters control swarms of drones. The GCAP’s Rolls-Royce engine, for example, emphasizes thermal efficiency and power output, hinting at this trend.
5. Reduced Radar Cross-Section (RCS)
Stealth remains a cornerstone of fighter design, but sixth-generation jets push the boundaries beyond fifth-generation standards. The F-22 boasts an RCS of 0.0001 square meters (marble-sized), while the F-35’s is around 0.0015 square meters (golf ball-sized). Sixth-generation designs aim for “orders of magnitude” lower RCS, potentially dipping below 0.00001 square meters. Innovations like tailless flying-wing configurations (seen in the J-36) and active stealth technologies—such as electronic cloaking or adaptive camouflage—counter emerging threats like quantum radar and multi-spectral sensors, ensuring survivability in highly contested environments.
6. Increased Endurance
Endurance, tied to range and fuel efficiency, is another area of advancement. Fifth-generation jets typically loiter for 1-2 hours in combat zones, constrained by fuel and engine design. Sixth-generation fighters, with their larger airframes and efficient propulsion—like the F-47’s adaptive engines or the J-50’s speculated diverterless supersonic inlets—could extend this to 4-6 hours. This prolonged presence enhances their role as “flying command centers,” orchestrating drone swarms and providing persistent situational awareness over vast areas, a capability fifth-generation jets can only partially achieve.
7. Diverse Aerodynamic Configurations
Aerodynamically, sixth-generation jets diverge from the fifth-generation norm of twin vertical stabilizers and minimal protrusions. Three distinct design philosophies are emerging: flying-wing layouts (e.g., Chengdu J-36’s tailless diamond-wing), canard-plus-flying-wing hybrids (e.g., speculated GCAP variants), and traditional wings with vertical stabilizers (e.g., Shenyang J-50’s cranked-arrow design). These configurations optimize stealth, lift, and maneuverability differently. The flying-wing approach maximizes broadband stealth, while canards enhance agility—echoing the J-20’s trade-off—albeit with RCS penalties mitigated by advanced materials. This variety suggests tailored mission profiles, from deep penetration to air superiority.
A Leap Beyond the Fifth Generation
While fifth-generation jets revolutionized air combat with stealth, sensor fusion, and supercruise, sixth-generation fighters build on this foundation with a “system-of-systems” ethos. Their larger IWBs and MTOWs enable greater lethality and flexibility, while increased range and endurance extend their strategic reach. Enhanced power generation supports futuristic weapons and AI-driven autonomy, and lower RCS ensures they remain ghosts to enemy defenses. The shift in design—whether flying wings or hybrid forms—reflects a response to evolving threats and operational needs.
NOTE: AFI is a proud outsourced content creator partner of IDRW.ORG. All content created by AFI is the sole property of AFI and is protected by copyright. AFI takes copyright infringement seriously and will pursue all legal options available to protect its content.