U.S. Air Force Extends F-15EX Fighter Jet Range With Additional Fuselage Fuel Tanks.

The Oregon U.S. Air National Guard’s 142nd Wing is flying two operational F-15EX Eagle II fighters with additional fuel tanks fitted closely along their fuselages, increasing onboard fuel capacity while preserving underwing positions for weapons. Known as conformal fuel tanks, the equipment was supplied by Air Combat Command. The configuration brings a capability previously used on F-15EX test aircraft into the operational fleet, although its effect on combat radius has not been disclosed.

An F-15EX Eagle II fitted with conformal fuel tanks that increase onboard fuel capacity while preserving underwing weapons stations. The red dotted outline highlights the tanks’ close-fitting position along the fuselage. (Picture source: Bill Shemley via TWZ)

Key Tactical Insights:

• F-15EX Range and Payload Optimization: Fitting fuselage-mounted tanks adds approximately 1,500 gallons of fuel per aircraft while preserving underwing hardware stations for heavy outsized weapons or external drop tanks.

• Weapons Integration Pylon Dependencies: Installing conformal tanks on the F-15EX does not confirm that their additional weapons stations are operational, as National Guard procurement proposals identify associated pylons as separate equipment that must still be acquired.

• Aerodynamic Drag and Performance Trade-offs: Because the F-15EX cannot jettison these fuselage-mounted tanks during flight, the configuration involves a permanent mission-planning trade-off that limits the aircraft's ability to shed weight and drag during an engagement.

• Operational Fleet Fielding Status: The public milestone remains limited to an approved flight configuration on two localized Oregon fighters, rather than establishing a verified combat-radius improvement or a funded, fleet-wide installation schedule.

According to information reported by The War Zone website on November 6, 2026, Oregon Air National Guard public affairs confirmed that the two aircraft had flown in the approved configuration for approximately two weeks. That places the start of those flights in late October; November 6 marks the public disclosure, rather than a first-flight date. One aircraft identified in the reporting is serial 20-0012.

Related Topic: U.S. Air Force Expands F-15EX Fleet With New Order for 22 Long-Range Strike Fighters

The distinction between test and operational aircraft is central to the development. Earlier F-15EX testing included conformal tanks, but the initial operational aircraft were funded for the F-15C/D replacement mission without them. The tanks are an established design, rather than newly developed equipment. The milestone is their use on two operational Oregon fighters, which does not establish a fleet-wide installation decision.

How the additional fuel tanks extend mission flexibility

A conformal fuel tank is an external tank shaped to follow the contours of an aircraft’s fuselage. On the F-15EX, a pair fits closely along the sides of the aircraft near the engine intakes. This arrangement generally produces less aerodynamic drag than conventional external drop tanks suspended beneath the wings, although the tanks still affect aircraft performance.

Each conformal tank holds approximately 750 U.S. gallons, giving a pair about 1,500 gallons of additional fuel capacity. Because they sit against the fuselage, they leave underwing attachment points available for weapons, other equipment or additional drop tanks, depending on the approved configuration.

The practical benefit is greater flexibility in balancing fuel and payload. Additional fuel can support longer transit distances or more time on station, while preserving underwing positions gives planners more options for external stores. However, fuel capacity alone does not determine combat radius. Weapons load, flight profile, fuel reserves, and aerial-refueling arrangements also influence how far a fighter can operate.

Unlike drop tanks, which pilots can release during flight, conformal tanks remain attached throughout a sortie. They can be removed on the ground, but the aircraft cannot shed them during an engagement to reduce weight and drag. Their use therefore involves a mission-planning trade-off between additional fuel and aircraft performance.

The procurement case also extends beyond the tanks themselves. An Oregon-sponsored draft resolution published by the National Guard Association of the United States on April 6, 2026, calls for F-15EX conformal tanks and associated equipment. It argues that external fuel tanks and outsized weapons compete for carriage positions, and identifies additional pylons as a separate procurement requirement. Its proposed future weapons configuration is an advocacy objective, rather than evidence of an already demonstrated operational load.

The F-15EX Eagle II and its expanding mission options

Built by Boeing, the F-15EX Eagle II is a two-seat, twin-engine multirole fighter that combines the Eagle airframe’s established configuration with modern flight controls, sensors and mission systems. Its equipment includes digital fly-by-wire controls, a large touchscreen cockpit display, an active electronically scanned array radar, and the Eagle Passive/Active Warning Survivability System, or EPAWSS, for electronic warfare. These systems modernize how the crew flies the aircraft, detects threats, and manages combat tasks.

Compared with the older F-15C, the Eagle II adds two weapons stations, along with an updated cockpit, radar, and electronic warfare capabilities, according to U.S. military information published through the U.S. Department of War/Defense information website. Those improvements provide greater weapons-carriage flexibility, although the load available for a particular mission depends on the equipment installed and the weapons configurations approved for use.

The conformal tanks address the fuel requirements associated with exploiting that flexibility. For air defense missions, additional fuel could support longer patrols or greater operating distances. For air-to-ground missions, preserving external attachment points could help accommodate weapons and supporting equipment. These are potential employment benefits, rather than measured results from the Oregon flights, and the configuration alone does not establish a reduction in tanker demand.

The confirmed milestone remains limited to two operational Eagle IIs flying with the approved tanks. No new measured combat radius, operational weapons load, or fielding schedule has been disclosed.

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Written by Alain Servaes – Chief Editor, Army Recognition Group
Alain Servaes is a former infantry non-commissioned officer and the founder of Army Recognition. With over 20 years in defense journalism, he provides expert analysis on military equipment, NATO operations, and the global defense industry.