Boeing F-15EX Eagle II: Old Airframe, New Capabilities

Posted by River Knox December 6, 2025
Boeing F-15EX Eagle II: Old Airframe, New Capabilities

This past June, the Portland Air Guard Station, Oregon, reached a new milestone, receiving its fourth Boeing F-15EX Eagle II just before the first anniversary of the base receiving the first of the modernized F-15 aircraft. The Oregon Air National Guard had been selected to be the first operator of the Eagle II, and with the arrival of the latest aircraft, is making progress towards receiving the planned 18 multirole fighters.

It was also that month that the White House announced that the United States Air Force’s total planned fleet size for the F-15EX could grow to 129 fighters. Aerospace giant Boeing has also leveraged the recent momentum to push for the restoration of the original program of record, which was 144 fighters, after the Air Force had previously reduced the planned acquisition to fewer than 100 fighters.

An F-15EX Eagle II from the U.S. Air Force soars over Gulf of America waters during a September 2025 test mission, demonstrating the multirole fighter's flight characteristics. The Eagle II undergoes Initial Operational Test and Evaluation. General Electric F-110 engines power the test aircraft. Pilots assess the fighter's Mach 2.5 speed capability. The Air Force evaluates deep magazine weapons capacity. Test missions originate from Florida air bases. Boeing supports ongoing flight evaluations. The modernized F-15 proves combat readiness. Evaluation data shapes future Eagle II upgrades.

The debate over the total fleet size is likely to continue, even as Boeing has sought to address rising costs, while questions have been raised about whether the aerospace firm will have the ability to produce the modernized F-15, develop and build the sixth-generation F-47, and still bid for the contract for the U.S. Navy’s F/A-18 Super Hornet replacement. Boeing currently produces that latter aircraft as well.

Modernized F-15

The F-15EX is just the latest chapter in the storied history of the fighter aircraft. The McDonnell Douglas F-15 Eagle, along with its ground-attack derivative, the F-15E Strike Eagle, has the distinction of being the most successful modern combat fighter, scoring more than 100 aerial kills with no combat losses. The twin-engine fighter, developed during the Cold War and entering service in the 1970s, is now in service with more than a dozen nations.

The first Boeing F-15EX Eagle II sits on the tarmac at Eglin Air Force Base in Florida following its historic delivery, marking the beginning of the modernized fighter's service with the U.S. Air Force. Eglin AFB hosts F-15EX test and evaluation. The 85th Test and Evaluation Squadron operates from Florida. Boeing delivered eight aircraft in initial production lots. The Eagle II began operational testing at Eglin. Air Force pilots trained on the new fighter platform. The delivery launched the F-15EX program. Florida serves as the Eagle II testing hub. Initial deliveries preceded Oregon Air National Guard aircraft.

During its service life, the F-15 had been steadily updated and improved, including the development of the F-15E Strike Eagle.

Boeing acquired McDonnell Douglas in August 1997 and continued production of the F-15E, as well as other variants, including the F-15SA for Saudi Arabia, and more recently, the F-15QA “Ababil” for the Qatari Emiri Air Force. The latter variant combined the time-tested platform with 21st-century technology. In 2017, Doha signed a contract for 36 of the fighters, and that could have been the end of the story.

An overhead view captures the F-15EX Eagle II on the ground at Eglin Air Force Base, revealing the fighter's twin-engine layout, conformal fuel tanks, and expansive weapons stations from above. The Eagle II features a strengthened airframe design. Conformal fuel tanks extend the fighter's range. Boeing engineered multiple hardpoints for ordnance. The twin-tail configuration provides stability at high speeds. Sensor systems integrate along the fuselage. The F-15EX carries 28% more payload than the Strike Eagle. Eglin AFB ground crews service the aircraft. The overhead angle shows weapons mounting positions.

However, it marked the beginning of the aircraft’s next chapter.

Eagle II Is Hatched

The United States Air Force was faced with many of its aging F-15C/D models reaching their end of life. At the same time, the last F-15E Strike Eagle was procured in 2001 and saw some of the benefits that the F-15QA offered, including that it has only around half the cost per flight hour of similar fighter aircraft, while delivering far more payload over greater ranges.

A Boeing F-15EX Eagle II taxis along the runway preparing for takeoff, the twin-engine fighter rolling toward its mission with engines spooling and control surfaces ready. The Eagle II prepares for flight operations. Twin General Electric F-110 engines produce 29,000 pounds of thrust each. Pilots conduct pre-takeoff system checks. The fighter's fly-by-wire controls respond to pilot inputs. Ground crews clear the taxiway for departure. The F-15EX accelerates rapidly on takeoff. Air National Guard units fly the modernized Eagle. Taxi procedures mirror legacy F-15 operations.

It was also determined that acquiring new models of the F-15 would be more cost-effective than following through with the “Golden Eagle” plan, which called for upgrading the older models.

The U.S. Department of Defense (DoD) and the U.S. Air Force carried out a Cost Assessment and Program Evaluation (CAPE) study in 2018 that indicated the service could affordably recapitalize its fleet with a mix of fourth-generation and fifth-generation fighters. A modernized F-15 was seen to be able to serve alongside the Lockheed Martin F-22 Raptor, the fifth-generation air superiority fighter that saw its program scaled back during the Global War on Terror (GWoT), and the Lockheed Martin F-35A Lightning II, the Air Force’s conventional takeoff and landing (CTOL) variant of the Joint Strike Fighter.

The underside of an F-15EX Eagle II is visible during its first test flight from Eglin Air Force Base, revealing the fighter's weapons pylons, conformal fuel tanks, and twin engine nacelles from below. The belly view shows hardpoint mounting locations. The Eagle II carries weapons on multiple stations. Conformal fuel tanks attach flush to the fuselage. Twin General Electric engines power the fighter overhead. The first test flight validated aircraft systems. Eglin AFB launched the inaugural F-15EX mission. The underside reveals the deep magazine capacity. Boeing engineers monitored the historic flight.

It was quickly determined that the F-15EX, lacking the stealth and other fifth-generation capabilities of the F-22 and F-35, wouldn’t be as survivable against advanced air defenses. Yet, it could supplement both of those aircraft with its standoff weapons and deeper magazine. It can also effectively perform homeland and airbase defense duties, which is why it is being deployed with Air National Guard units.

In 2020, the U.S. Air Force announced it would acquire upwards of 144 of the new aircraft, designated the F-15EX. In July 2020, the Department of Air Force awarded a nearly $1.2 billion contract for the first lot of eight F-15EX fighters.

A 4.5 Generation Fighter

While based on the F-15QA, the F-15EX was developed as a two-seat, all-weather, multirole fighter that offers enhanced capabilities unique to the U.S. Air Force. Boeing has touted it as a fourth-generation plus fighter, which some analysts have referred to as a “4.5 generation” multirole fighter, allowing it to bridge the gap to more advanced aircraft.

The F-15EX Eagle II taxis to parking at The Great Texas Airshow 2022, the twin-engine fighter drawing attention from crowds gathered at Joint Base San Antonio to see America's newest combat aircraft. The airshow featured cutting-edge military hardware. Visitors observed the Eagle II's distinctive profile. The F-15EX represented next-generation F-15 technology. Ground crews guided the fighter to display position. San Antonio hosted thousands of aviation enthusiasts. The modernized fighter highlighted Air Force investments. Public events introduce citizens to defense programs. The 2022 appearance preceded wider operational deployment.

The Eagle II was further outfitted with newly adapted technologies, and the platform was designed to be upgradeable, making it a viable, lethal, and high-threat environment-capable attack platform for years to come. Among the key features offered by the Eagle II are its fly-by-wire flight controls, new weapons stations, a new electronic warfare suite, advanced radar and computer, conformal fuel tanks, and a strengthened airframe.

Boeing has stated that the F-15EX can facilitate rapid technology insertion, enabling the platform to be updated with new capabilities. The aerospace firm explained that this will be accomplished via an “Open Mission System Architecture.” Among the advanced features of the Eagle II is the integration of Advanced Battle Management Systems (ABMS) functionality, which will further enable the F-15EX to operate independently while also allowing it to connect to the U.S. military’s Combat Cloud utilized by fifth-generation aircraft.

In April 2024, the U.S. Air Force completed the Initial Operational Test & Evaluation of the Eagle Passive Warning Survivability System (EPAWSS). The system was touted to enhance the electronic warfare (EW) capabilities of both the F-15E Strike Eagle and F-15EX Eagle II. EPAWSS was developed for upgradeability and rapid capability insertion, enabling the aircraft to defeat current and future electromagnetic threats.

According to BAE Systems, the EPAWSS offers “several instantaneous full-spectrum EW capabilities — including radar warning, geolocation, situational awareness, and self-protection. The contractor further highlighted that this system enabled freedom of maneuver and deeper penetration into battlespaces protected by modern integrated air defense systems.”

Deadly Warbird

The F-15EX was developed to be powered by two General Electric F-110-GE-129 engines, each producing around 29,000 pounds of thrust with afterburner. The engines could enable the aircraft to reach a top speed of Mach 2.5 (two and a half times the speed of sound), or approximately 1,900 mph (3,000 km/h), making it one of the fastest fighter aircraft in service today. In addition, the engines have a proven track record, with reduced maintenance time, which helps improve readiness while being cost-effective.

An F-15EX Eagle II releases a missile over the Gulf of America during a November 2025 weapons test, flame and exhaust trailing behind the launched munition as the fighter demonstrates its combat capability. The Eagle II carries AIM-9X Sidewinder missiles. The F-15EX launches AIM-120 AMRAAM rounds for beyond-visual-range engagements. Boeing designed the fighter with a deep magazine. The multirole aircraft holds up to 22 missiles. Live-fire tests validate weapons integration. The Air Force evaluates precision-guided munitions delivery. New weapons stations expand the Eagle II's lethality. Test ranges over the Gulf support missile evaluations.

The F-15EX has also been noted for being equipped with a “deep magazine,” which allows it to carry a significantly larger payload than other fighters, as well as a diverse load of advanced weapons. The Eagle II was developed with a 28% greater payload capability than the F-15E Strike Eagle. In total, the modernized fighter could carry up to 22 missiles, including AIM-9X Sidewinders, which can be used in close-range engagements, as well as the AIM-120 AMRAAMs for beyond-visual-range (BVR) engagements. It could further carry precision-guided munitions, including JDAMs, smart weapons such as the Stormbreaker, and even hypersonic weapons.

The F-15EX was also developed to operate with the RIM-174 Standard Extended Range Active Missile (ERAM), the munition originally designed to be carried by the U.S. Navy’s F/A-18 Super Hornets, and based on the sea service’s Standard Missile 6 (SM-6) surface-to-air missile used on Arleigh Burke-class guided-missile destroyers.

An F-15EX Eagle II conducts a test flight along the north Florida beaches, the twin-engine fighter soaring over turquoise waters and white sand during evaluation operations based out of Eglin Air Force Base. Coastal test routes provide varied flight conditions. The Eagle II evaluates performance over water and land. Eglin AFB sits near the Florida Gulf coastline. Pilots assess aircraft handling along beach corridors. The F-15EX flies test patterns over the Gulf region. North Florida offers ideal testing airspace. Boeing monitors flight data from coastal sorties. Beach overflights demonstrate low-altitude capabilities.

According to U.S. Air Force estimates, the F-15EX Eagle II shares approximately 70% of its parts and key components with the current F-15Cs and F-15E Strike Eagles that it is replacing. That was seen as streamlining supply chain challenges that come with a new aircraft. Boeing has further noted that the original McDonnell Douglas production lines in St. Louis, Missouri, remained operational, allowing for a rapid transition to the manufacturing of the warplane. Additionally, the original aircraft’s training facilities, maintenance depots, and other infrastructure have been reallocated to support the F-15EX.

Moreover, while the Eagle II lacks some of the capabilities of the fifth-generation F-35, the United States Air Force’s Directorate of Operational Test and Evaluation (DOT&E) wrote in its 2024 annual report that the F-15EX had proven to have a significantly higher mission-capable (MC) rate over the F-35 or even the Lockheed Martin F-22 Raptor. The Eagle II was able to achieve an 83.13% mission-capable rate, compared with the Lightning II’s MC rate of 67.15% across all variants.

The Slow Rollout

The Eagle II also serves as a reminder that modern aircraft, even those that share many similarities with older fighters, take time to build. That explains why only a handful of Eagle II have hatched, with just eight manufactured in the initial Lots 1A and 1B, which were completed in the summer of 2024.

With the arrival of the ninth aircraft, EX9, in early 2025, Boeing began Lot 2 production, and with each batch, the aerospace firm announced plans to deliver additional aircraft.

Defending the Keystone of the Pacific

In July, the first two F-15EX Eagle II multirole fighters arrived at Kadena Air Base, Japan, having flown to the base from Eglin Air Force Base (AFB) in Florida. The deployment of the 85th Test and Evaluation Squadron’s aircraft was to prepare for “integration and familiarization training with local units and joint partners,” the U.S. Air Force announced shortly after the Eagle IIs arrived.

The F-15EX Eagle II conducts training operations from Nellis Air Force Base in 2023, the twin-engine fighter navigating Nevada skies during exercises designed to prepare pilots for real combat situations. Nellis serves as the Air Force's premier training base. The Eagle II integrates with other fighter aircraft. Desert ranges simulate contested battlespaces. Pilots practice beyond-visual-range engagements. The F-15EX demonstrates its deep magazine advantage. Training flights test electronic warfare systems. Nevada exercises prepare crews for Pacific missions. The 2023 operations expanded Eagle II tactical development.

The two are the first of the planned three dozen Eagle IIs that will touch down at Kadena next spring. The F-15EX will be permanently based on the Japanese island of Okinawa at Kadena. The island, and more specifically the base, has earned the nickname “Keystone of the Pacific” due to its strategic location for US military operations in the Indo-Pacific. It has remained the largest and most active US Air Force base in the region.

The final F-15C Eagle departed from Kadena on January 24, 2025, marking the end of 45 years of flight operations from the base on Okinawa.

Foreign Military Sales of the F-15EX

The United States Air Force is likely to remain the primary operator and testbed for the F-15EX, but already multiple nations have lined up to acquire the modernized Eagle.

Two F-15EX Eagle II fighters cruise together over Florida skies, the Boeing-built aircraft flying in formation during training operations that develop the tactics for this modernized platform. Paired Eagle IIs practice mutual support tactics. Florida hosts multiple F-15EX test operations. Formation flights validate communication systems. The fighters coordinate through advanced avionics. Two-ship tactics date back to original F-15 doctrine. The F-15EX maintains formation flying traditions. Pilots develop teamwork over Florida ranges. Dual-aircraft missions increase training realism.

That has included Saudi Arabia, with Riyadh expressing intent to purchase as many as 54 of the aircraft to upgrade its fleet of F-15SA fighters to the EX standard. Other nations that are now considering an acquisition of the Eagle II include Egypt, Indonesia, Poland, Qatar, Singapore, South Korea, and Thailand.

The Israeli Air Force (IAF) currently has a program of record for 25 aircraft, designated the F-15IA, and that order could be increased to 50. The deal, valued at as much as $18.81 billion, also included mid-life upgrades for the IAF’s fleet of F-15I Ra’am fighters, the Israeli-specific variant of the F-15E Strike Eagle.

As with other IAF fighter variants, the F-15IA features Israeli-specific systems, including a Joint Helmet-Mounted Cueing System, and is equipped to carry an array of Israeli-made munitions.

Ground crews from Kadena Air Base receive F-15EX weapons loading training at Portland Air National Guard Base during 2025, preparing for the 36 Eagle II fighters scheduled to arrive at the Pacific installation. Airmen practice arming the modernized fighter. Portland's Oregon Air National Guard provides instruction. Kadena prepares infrastructure for Eagle II operations. Weapons handlers learn deep magazine loading procedures. The training covers precision-guided munitions installation. Ground crews study the fighter's weapons stations. Pacific deployment requires fully trained maintenance teams. Cross-base training accelerates operational readiness.

The United States Defense Security Cooperation Agency, which is tasked with overseeing foreign military sales (FMS), has announced it is committed to maintaining Israel’s qualitative military edge over its neighbors, while the adoption of the Eagle II would enhance Israel’s interoperability with U.S. systems and bolster Israel’s aerial capabilities to meet current and future enemy threats, strengthen its homeland defense, and serve as a deterrent to regional threats.

Future EW Aircraft

Beyond its integration of the EPAWSS, in July 2024, Boeing announced it was studying whether the F-15EX Eagle II could serve in a role similar to the EA-18G Growler, the EW variant of the U.S. Navy’s F/A-18 Super Hornet. As Boeing already produces the Super Hornet and Growler, it wouldn’t be a great leap for the aerospace firm.

A view into the cockpit of an F-15EX Eagle II during flight, photographed from another aircraft flying above, shows the pilot operating the modernized fighter's advanced avionics and control systems. The cockpit features modern digital displays. Fly-by-wire controls respond to pilot inputs. The Eagle II pilot manages advanced radar systems. Cockpit ergonomics blend legacy design with new technology. The canopy provides excellent visibility for the crew. Pilots access EPAWSS electronic warfare information. The F-15EX cockpit supports Combat Cloud integration. In-flight photography captures operational conditions.

The study was reported to be in the “nascent” stage a year ago, but with F/A-18E/F production set to come to an end in 2027 and no orders for the EA-18G, Boeing may seek to add features to keep the manufacturing lines running. It could also offer a low-cost alternative to foreign partners, providing an EW aircraft for operations that don’t require stealth, which is often a feature of the more expensive fifth-generation options.

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