Executive Summary:
The U.S. Air Force is examining future propulsion options for its F-15EX Eagle II and F-16 Fighting Falcon fleets as part of a broader effort to strengthen long term competition and sustainment. The review comes as the service prepares for decades of continued operation of both fighter platforms while balancing readiness, affordability, and industrial base resilience.
US Air Force Studies Alternative Engines For F-15EX And F-16
The F-15EX alternative engines initiative signals a renewed Air Force interest in increasing competition for propulsion systems supporting two of its most important fourth generation fighter fleets. Air Force officials are evaluating whether additional engine options could reduce long term sustainment costs and improve operational flexibility.
The F-15EX currently flies with the GE Aerospace F110,GE,129 engine, while many F-16 variants operate either General Electric F110 engines or Pratt & Whitney F100 engines depending on aircraft block and operator. The Air Force’s review does not represent an immediate procurement decision but instead explores future pathways as fleet requirements evolve.
Why The Air Force Is Revisiting Fighter Engine Competition
Historically, engine competition has been viewed as a way to encourage innovation while providing leverage on pricing and sustainment.
The F-15EX program initially experienced debate over whether a sole source engine procurement or a competitive process would best support rapid fielding. Ultimately, the Air Force selected the GE F110 because it had already completed integration and certification with the aircraft’s digital fly by wire flight control system, minimizing schedule risk.
For the F-16 fleet, both GE Aerospace and Pratt & Whitney engines have powered different production blocks for decades, providing the Air Force and international operators with experience supporting multiple propulsion options.
Current Engine Configuration
Aircraft Current Primary Engine Notes F-15EX Eagle II GE F110,GE,129 Fully integrated and certified for the aircraft F-16 Fighting Falcon GE F110 or Pratt & Whitney F100 Depends on production block and operator Strategic Importance Beyond Procurement
The engine review reflects more than a technical exercise.
The Air Force expects both aircraft to remain operational well into the 2030s and beyond. The F-15EX continues replacing aging F-15C aircraft while assuming homeland defense and long range weapons carriage missions. Meanwhile, upgraded F-16s remain essential for homeland operations, training, and numerous overseas deployments.
Because propulsion systems account for a significant portion of lifecycle operating costs, even modest improvements in maintenance requirements, fuel efficiency, spare parts availability, or reliability can produce substantial savings across hundreds of aircraft.
Technical Challenges Of Introducing A New Engine
Although evaluating alternative engines appears straightforward, integrating a new propulsion system into an existing fighter is a complex engineering effort.
Certification typically requires:
- Flight testing across the aircraft’s operating envelope.
- Software integration with flight control systems.
- Validation of cooling, electrical, and hydraulic interfaces.
- Structural analysis of engine mounts.
- Logistics and maintenance qualification.
- Airworthiness certification.
For the F-15EX, these integration requirements were one of the principal reasons the Air Force previously favored the already qualified GE F110 rather than introducing another engine option.
Broader Implications For U.S. Air Power
The Air Force’s review also reflects broader concerns about maintaining a healthy defense industrial base.
Maintaining multiple capable propulsion suppliers can strengthen supply chain resilience, reduce dependence on a single manufacturer, and preserve engineering expertise that could benefit future combat aircraft programs.
At the same time, introducing competition must be balanced against integration costs and the operational risks associated with certifying new propulsion systems.
As the Air Force modernizes its tactical aviation fleet alongside sixth generation development efforts, sustaining highly capable fourth generation fighters remains a critical element of overall force structure. Aircraft such as the F-15EX provide exceptional payload capacity, long range, and the ability to carry emerging long range air to air and strike weapons that complement stealth aircraft rather than replace them.
What Happens Next
Air Force officials have not announced a formal engine competition or acquisition timeline.
Instead, the current effort appears focused on understanding available propulsion technologies, future sustainment strategies, and potential industrial benefits before any procurement decisions are made.
If the study eventually leads to competitive engine procurement, it could influence sustainment planning for hundreds of fighters that are expected to remain in service for decades.
Executive Summary:
Israel has approved a multibillion-dollar procurement plan to acquire advanced U.S.-built fighter jets, including additional F-35 Lightning II aircraft. The move aims to sustain its qualitative military edge and counter evolving regional threats. The deal reinforces defense ties with the United States while accelerating Israeli Air Force modernization.
Israel Expands Fifth-Generation Fighter Fleet
Israel’s Defense Ministry has formally endorsed a major acquisition package centered on expanding its fleet of F-35 Lightning II aircraft, alongside potential procurement of advanced variants of the F-15EX Eagle II.
The deal, estimated in the multi-billion-dollar range, includes:
- Additional F-35I Adir stealth fighters
- Upgraded F-15 platforms optimized for heavy payload missions
- Long-term sustainment and support packages
The aircraft will be supplied by Lockheed Martin and Boeing under existing U.S. foreign military financing frameworks.
Key Capabilities Driving the Procurement
Fifth-Generation Stealth and Network Warfare
The F-35 remains central to Israel’s airpower doctrine due to its:
- Low observable stealth design for contested environments
- Advanced sensor fusion and data-sharing capabilities
- Integration into multi-domain operations
Heavy Strike and Payload Flexibility
The F-15EX complements the F-35 with:
- Higher payload capacity for long-range strike missions
- Ability to carry hypersonic and stand-off weapons
- Extended operational range without refueling
Comparison: New Fighters vs Legacy Platforms
Aircraft Range Payload Status Key Technology F-35I Adir ~2,200 km ~8,160 kg Operational/Expanding Stealth, sensor fusion F-15EX ~3,900 km ~13,300 kg Pending acquisition Advanced avionics, heavy payload Legacy F-16I ~1,700 km ~7,700 kg In service Multirole, non-stealth Older F-15 variants ~3,000 km ~10,400 kg Aging fleet Conventional radar systems Strategic Context: Maintaining Regional Air Superiority
Israel’s decision reflects a broader shift in regional threat dynamics, including:
- Expanding air defense networks across the Middle East
- Growing missile and UAV capabilities among adversaries
- Increased great-power competition in the region
By combining stealth penetration capabilities with high-payload strike platforms, Israel aims to maintain its long-standing qualitative military edge (QME).
U.S.-Israel Defense Alignment Strengthened
The procurement underscores continued strategic alignment with the United States, particularly in:
- Joint technology development
- Defense financing and export approvals
- Interoperability across allied systems
This agreement also reinforces Washington’s role as Israel’s primary defense supplier, while supporting U.S. aerospace industry production lines.
Outlook: Timeline and Operational Impact
Deliveries are expected to occur over the next decade, with phased integration into Israeli Air Force units. Once operational, the expanded fleet will:
- Enhance deep-strike capabilities
- Improve survivability in contested airspace
- Support multi-front operational readiness
The deal positions Israel to respond more effectively to both conventional and asymmetric threats in an increasingly complex security environment.
Why the F-15 Fighter Jet Still Matters
Few combat aircraft have achieved the reputation of the F-15 fighter jet, a platform that has defined U.S. and allied airpower since the mid-1970s. Developed by McDonnell Douglas (now Boeing), the F-15 was designed as a pure air superiority fighter to ensure the U.S. Air Force could defeat Soviet aircraft during the Cold War.
Half a century later, the aircraft is still in frontline service, upgraded and adapted for new missions ranging from strike to electronic warfare. Its latest variant, the F-15EX Eagle II, represents an effort to extend the aircraft’s relevance into the next generation, balancing payload and survivability against stealth-centric designs like the F-35.
Origins of the F-15 Fighter Jet
The program for the F-15 began in the late 1960s after the U.S. Air Force sought a dedicated air superiority fighter following lessons from Vietnam. McDonnell Douglas won the contract in 1969, and the first flight took place in 1972.
When it entered service in 1976, the F-15 Eagle was revolutionary: twin-engine reliability, a large radar aperture, and a thrust-to-weight ratio greater than 1:1, allowing it to accelerate while climbing vertically.
From the outset, the F-15’s motto was clear: “Not a pound for air-to-ground.” It was built to dominate the skies, a role in which it still boasts a remarkable combat record.
Combat Record and Legacy
The F-15 fighter jet has accumulated one of the most impressive records in aerial combat: over 100 air-to-air kills with zero losses in air-to-air engagements, largely credited to Israeli, Saudi, and U.S. Air Force operations.
- Israel first used the F-15 in combat in 1979, scoring dozens of kills over Syrian aircraft in Lebanon.
- Saudi F-15s achieved kills during the Iran–Iraq War and later in Desert Storm.
- The U.S. Air Force relied heavily on the F-15C for air dominance during Operation Desert Storm (1991), where it achieved the majority of coalition air-to-air kills.
This legacy gave the F-15 a reputation as one of the most successful fighter designs ever fielded.
Evolution of the F-15 Variants
Over time, the F-15 family expanded to meet changing requirements:
- F-15A/B (1970s) – Original single- and two-seat versions for air superiority.
- F-15C/D (1980s) – Improved avionics, conformal fuel tanks, and extended range.
- F-15E Strike Eagle (1988 onward) – A dual-role fighter capable of precision strike and deep interdiction, with two-seat cockpit for pilot and weapons officer.
- F-15SA / F-15QA – Advanced export variants with digital flight controls, modern avionics, and expanded payloads for Saudi Arabia and Qatar.
- F-15EX Eagle II (2020s) – The newest U.S. variant with advanced electronic warfare systems, modern cockpit displays, fly-by-wire controls, and hypersonic weapon compatibility.
The F-15EX: Future of the Eagle
The U.S. Air Force ordered its first F-15EX Eagle II aircraft in 2020 to replace aging F-15C/D fleets.
Key features include:
- Payload capacity: up to 29,500 lbs, the heaviest among U.S. fighters.
- Weapons carriage: 12 AMRAAM-class missiles or a mix of bombs, missiles, and hypersonics.
- EPAWSS electronic warfare suite for survivability in contested airspace.
- Digital backbone enabling faster software updates and integration with unmanned systems.
- Two-seat design adaptable for collaborative combat with drones.
Unlike stealth aircraft, the F-15EX is designed to carry heavy payloads and serve as a “weapons truck,” complementing stealth fighters in large-scale operations.
Global Operators of the F-15 Fighter Jet
The F-15 remains in use across several air forces:
- United States – Operates F-15C/D, F-15E Strike Eagle, and now F-15EX.
- Israel – One of the earliest and most effective operators.
- Saudi Arabia – Fields one of the largest F-15 fleets, including advanced F-15SA.
- Japan – Locally produced under license; now upgrading to F-15JSI standard.
- Qatar – Fields the latest F-15QA variant.
- South Korea & Singapore – Both operate the Strike Eagle variant.
These nations highlight the F-15’s continued relevance, with several investing in modernization programs rather than retiring the type.
Analysis: The F-15’s Place in the Modern Era
Despite its legacy, the F-15 fighter jet competes in an era dominated by stealth, network-centric warfare, and emerging sixth-generation projects. Critics argue that in heavily defended airspace, its non-stealth profile limits survivability.
Yet, the F-15 offers advantages:
- unmatched payload capacity,
- proven range and reliability,
- ability to integrate future weapons like hypersonics.
For the U.S. and allies, the F-15EX provides a cost-effective bridge between legacy fourth-generation aircraft and future sixth-generation systems like NGAD (Next Generation Air Dominance). Its role as a complement — not competitor — to stealth platforms gives air forces flexibility in planning strike packages.
FAQs
Its combination of speed, power, and payload has made it one of the most successful fighters in history, with an undefeated air-to-air record.
The F-15EX Eagle II, now entering U.S. Air Force service.
The F-15 can reach speeds of Mach 2.5 (around 1,650 mph).
At least eight countries, including the U.S., Israel, Japan, Saudi Arabia, South Korea, Qatar, and Singapore.
Yes. With upgrades and new variants like the F-15EX, the fighter is expected to remain operational well into the 2040s.