Why the F-35 Stealth Fighter Can Carry More Fuel Than the F-22

When comparing the F-35 and F-22 stealth fighters, it's often surprising to note that despite the F-22 seemingly being a smaller aircraft in side-by-side comparisons, the F-35 has a significantly greater fuel capacity. This article explains the underlying reasons for this discrepancy.

Design Philosophy and Internal Fuel Capacity

At the core of the F-35's greater fuel capacity lies its design philosophy. The F-35 was envisioned as a versatile multi-role stealth fighter with a focus on operational flexibility, versatility, and extended range. This design approach places a greater emphasis on internal fuel storage to support extended missions. In contrast, the F-22 Raptor was designed primarily for air superiority and to achieve supercruise capability. While both aircraft are stealthy, the F-22's design prioritizes efficiency and performance over extended range capabilities.

The F-35 has a substantial internal fuel capacity of about 18,500 pounds (1). This is compared to the F-22, which carries approximately 18,000 pounds of fuel internally. The internal fuel tanks in the F-35 are optimized to make the most efficient use of the aircraft's space, making the F-35 more fuel-efficient overall.

Wing Design and Airframe Structure

The F-35's wings are designed to maximize fuel storage while maintaining aerodynamic efficiency. The wing structure allows for larger fuel tanks to be integrated without significantly compromising the aircraft's performance. The F-35's airframe structure is also designed to accommodate additional fuel in various sections, including the fuselage and wings. This compact yet efficient design maximizes fuel capacity while maintaining the aircraft's maneuverability and stealth capabilities.

Mission Requirements and Stealth Characteristics

The F-35's design philosophy includes a broader range of missions, from ground attack to intelligence, surveillance, and reconnaissance (ISR). These missions necessitate longer ranges and a greater fuel capacity. While the F-22 also has advanced stealth characteristics, its design focuses more on air superiority and supercruise capability. The F-22's more compact airframe design may not prioritize fuel capacity as extensively as the F-35. This comparative design choice reflects the different mission requirements of the two aircraft: the F-22 excels in short-range combat and rapid response, whereas the F-35 is optimized for a wider range of longer-range missions.

Engine and Missiles Capacity Disparities

Another factor contributing to the F-35's greater fuel capacity is the weight difference between the aircraft's engines and the number of internal weapons stations. The F-22 airframe houses two F119-PW-100 engines, each operating in the 35,000-pound thrust class. The F-35, in contrast, uses a single F135-PW-100 engine, operating in the 45,000-pound thrust class. Although the F-35 has a more powerful engine, this does not equate to a proportional loss in fuel capacity. (2)

The F-22 has an internal weapons bay space for 6 x AIM-120 AMRAAM and 2 x AIM-9 Sidewinder missiles, totaling 8 missiles. The F-35A, on the other hand, has a substantially reduced internal weapons bay capacity, with only 4 internal weapons stations, and 6 with the Sidekick system. When you consider that carrying more missiles would detract from the available fuel capacity, it becomes clear that the F-22 and F-35 are optimized differently for their respective roles.

Conclusion

In summary, the F-35's design emphasizes versatility, extended range, and operational flexibility, allowing it to carry more fuel than the F-22 despite its smaller appearance. The F-35's superior internal fuel capacity, optimized wing design, and airframe structure contribute to its greater fuel efficiency. Meanwhile, the F-22 is optimized for air superiority and short-range combat, prioritizing stealth and performance over extended range capabilities.

References: 1 - 2

Internal fuel capacity of F-35A compared to F-22. Thrust comparison and engine weight of F119 and F135 engines.