- RTX awarded $3.81 billion contract modification for F135 propulsion systems supporting F-35 Lot 18 and Lot 19 production.
- Contract covers U.S. Air Force, Navy, Marine Corps, international partners, and Foreign Military Sales customers.
- Work spans multiple U.S. locations with completion expected by March 2028.
- Funding includes FY2024 and FY2025 aircraft procurement accounts plus partner and FMS contributions.
- Contract awarded by Naval Air Systems Command on a non-competitive basis.
RTX Secures Major F135 Engine Contract For F-35 Production
RTX has secured a $3.8 billion F135 engine contract to support ongoing F-35 production, reinforcing its central role in powering the Joint Strike Fighter fleet. The award, issued by Naval Air Systems Command, finalizes production terms for Lot 18 and advances procurement for Lot 19 aircraft.
The contract modification converts a previously undefinitized agreement into a finalized structure while adding new production scope. It reflects continued demand for the F-35 program across U.S. services and international partners.
Scope And Structure Of The Contract
The $3,813,591,875 modification covers the production of F135 propulsion systems, the sole engine used across all variants of the F-35 fighter. This includes aircraft operated by the U.S. Air Force, Navy, and Marine Corps, as well as allied nations participating in the program and Foreign Military Sales customers.
The contract combines cost-plus-incentive-fee and fixed-price incentive elements. This hybrid structure is commonly used in large defense programs to balance cost control with performance incentives, particularly when production complexity remains high.
Funding allocations reflect the multinational nature of the F-35 program. Contributions come from U.S. fiscal year 2024 and 2025 aircraft procurement budgets, alongside partner nation funding and a significant share from Foreign Military Sales.
Notably, more than $1.46 billion of the total comes from FMS customers, highlighting continued export demand for the F-35 platform.
Industrial Base And Production Footprint
Work under the F135 engine contract will be distributed across a broad U.S. industrial base. Key locations include Connecticut, Indiana, Washington, Maine, California, and several other states, with additional work conducted both within and outside the continental United States.
East Hartford, Connecticut, accounts for the largest share at 17 percent, reflecting RTX’s primary engine manufacturing hub. Other notable contributions come from Indianapolis, Middletown, and Kent, Washington.
This distributed production model supports supply chain resilience and aligns with Pentagon priorities to maintain a robust domestic defense industrial base.
From an operational standpoint, the wide geographic spread also reduces risk tied to localized disruptions, a factor that has gained importance in recent years due to global supply chain pressures.
Program Significance And Strategic Context
The F135 engine contract is a critical component of the broader F-35 program, which remains the cornerstone of U.S. and allied tactical airpower. As production transitions from early low-rate initial production to more sustained output, engine manufacturing has become a key pacing element.
Delays or inefficiencies in propulsion system delivery can directly impact aircraft rollout schedules. By definitizing Lot 18 and advancing Lot 19 procurement, the Pentagon is signaling confidence in production stability moving forward.
The inclusion of international partner funding also underscores the program’s long-term sustainability. Countries across Europe, Asia, and the Middle East continue to invest in the F-35, ensuring steady demand for engines well into the next decade.
At the same time, the reliance on a single engine type for all F-35 variants continues to draw attention. While it simplifies logistics and maintenance, it also creates a single point of dependency within the supply chain. This makes contracts like this one essential for maintaining production continuity.
Funding Breakdown And Timeline
The contract pulls from multiple funding streams, including:
- FY2024 Navy aircraft procurement
- FY2024 Air Force aircraft procurement
- FY2025 Navy and Air Force procurement funds
- Cooperative program partner contributions
- Foreign Military Sales funding
A portion of the obligated funds, approximately $430.8 million, is set to expire at the end of the current fiscal year. This adds urgency to execution timelines and reinforces the need for efficient contract performance.
The program is scheduled for completion by March 2028, aligning with projected F-35 production timelines for Lot 18 and Lot 19 aircraft.
Acquisition Strategy And Industry Implications
The contract was awarded on a non-competitive basis, consistent with RTX’s position as the sole manufacturer of the F135 engine. While this limits competition, it reflects the technical complexity and certification requirements associated with fifth-generation fighter propulsion systems.
From a policy perspective, the award highlights ongoing challenges in balancing competition with program continuity in high-end defense systems. Developing an alternative engine for the F-35 would require significant investment and time, making near-term competition unlikely.
However, the scale of the contract and the long-term demand profile could renew discussions around future propulsion upgrades or alternative engine programs.
Outlook For The F-35 Program
The latest F135 engine contract reinforces the steady momentum of the F-35 program despite past cost and sustainment concerns. Continued investment from both the United States and international partners suggests strong confidence in the platform’s operational value.
As production ramps up and more aircraft enter service globally, engine reliability, maintenance efficiency, and lifecycle cost will remain key focus areas.
For RTX, the contract secures a significant revenue stream while strengthening its position within the defense propulsion market.
RTX F135 propulsion system contract supports F-35 Lot 20 production
RTX Corp. has been awarded a not to exceed $230.6 million F135 propulsion system contract to protect the F-35 Lot 20 engine delivery schedule, according to a U.S. Department of Defense contract announcement. The agreement funds long lead time materials and components needed to sustain production of 138 F135 engines for the U.S. Air Force, Marine Corps, Navy, international partners, and Foreign Military Sales customers.
The contract was issued by Naval Air Systems Command at Patuxent River, Maryland, and was not competitively awarded.
Contract scope and structure
The RTX F135 propulsion system contract is structured as a combination fixed price incentive, firm target, cost plus incentive fee, advanced acquisition, undefinitized contract. Its primary purpose is to secure critical materials, parts, and manufacturing efforts required to prevent schedule disruptions in the F-35 Lot 20 production cycle.
Long lead items are essential for the F135 engine due to its complex global supply chain, specialized materials, and extended manufacturing timelines. Funding these elements early helps stabilize production and reduce downstream risks as full-rate manufacturing ramps up.
The effort supports 138 propulsion systems across multiple customers, reflecting the multinational nature of the F-35 program and the shared reliance on the F135 engine as its sole powerplant.
Production locations across the United States
Work under the RTX F135 propulsion system contract will be performed across a broad U.S. industrial base, underscoring the engine program’s economic and strategic footprint.
Key workshare locations include:
East Hartford, Connecticut, 17 percent
Indianapolis, Indiana, 10 percent
Middletown, Connecticut, 8 percent
Kent, Washington, 7 percent
North Berwick, Maine, 4 percent
El Cajon, California, 3 percent
Cromwell, Connecticut, 3 percent
Whitehall, Michigan, 3 percent
Portland, Oregon, 2 percent
San Diego, California, 2 percent
South Bend, Indiana, 2 percent
Columbus, Georgia, 1 percent
Hampton, Virginia, 1 percent
Manchester, Connecticut, 1 percent
Cheshire, Connecticut, 1 percent
Elmwood Park, New Jersey, 1 percent
Various locations across the continental United States, 34 percentThe contract is scheduled for completion in May 2031.
Funding breakdown and fiscal details
Funding for the RTX F135 propulsion system contract comes from multiple sources tied to both U.S. and international F-35 procurement.
At the time of award, the following funds will be obligated:
$35.22 million from fiscal 2025 Air Force aircraft procurement funds
$26.63 million from fiscal 2025 Navy aircraft procurement funds
$42.68 million from non U.S. Department of Defense partner Navy funds
$126.03 million from Foreign Military Sales fundsNone of the obligated funds will expire at the end of the current fiscal year, providing budget stability for the long lead procurement effort.
Importance of the F135 engine to the F-35 program
The Pratt and Whitney F135, produced by RTX, is the most powerful fighter engine currently in operational service. It powers all three variants of the F-35 Lightning II, including the conventional takeoff and landing F-35A, the short takeoff and vertical landing F-35B, and the carrier-capable F-35C.
Ensuring on-time delivery of F135 engines is critical to meeting aircraft production targets set by the U.S. services and international customers. Engine delays can cascade across final assembly lines, pilot training pipelines, and operational unit stand-ups.
The Lot 20 production phase comes as the F-35 program continues to recover from earlier supply chain disruptions and modernization challenges, making early investment in long lead items a priority for program managers.
Strategic implications for allies and partners
A significant portion of the contract funding is tied to non U.S. Department of Defense partners and Foreign Military Sales customers. This reflects continued demand for the F-35 among allied air forces and the importance of maintaining a predictable delivery schedule.
Stable F135 engine production supports partner confidence in the F-35 enterprise and helps align multinational fleet growth with shared training, sustainment, and operational planning efforts.
By securing long lead materials now, the U.S. Navy and its partners aim to reduce risk as international F-35 fleets expand through the late 2020s and early 2030s.
Oversight and contracting authority
Naval Air Systems Command is the contracting activity for the RTX F135 propulsion system contract. NAVAIR manages naval aviation acquisition programs and plays a central role in coordinating engine procurement for both Navy and Marine Corps F-35 variants, while also supporting joint and international stakeholders.
The contract is identified under reference number N0001926C0118.
Patria, Pratt and Whitney Expand Finland F 35 Engine Assembly Capability
Patria and Pratt and Whitney have finalized an agreement enabling final assembly of the F135 engine in Finland for the country’s F 35 Lightning II fleet, a move that significantly expands domestic sustainment capacity for the Finland F 35 program.
The agreement supports Finland’s HX Fighter Program and reinforces national security of supply by ensuring critical propulsion system expertise remains available within the country throughout the F 35 lifecycle.
The announcement was confirmed by Patria and Pratt and Whitney, an RTX business, as part of broader industrial cooperation tied to Finland’s acquisition of 64 F 35A fighters.
Strengthening Finland’s F 35 Sustainment Ecosystem
Under the agreement, Patria will perform final assembly operations for the F135 engine, the sole powerplant for all variants of the F 35 Lightning II. The work will be carried out at Patria facilities in Finland and will support both operational readiness and long term sustainment of the Finnish Air Force’s future fighter fleet.
The F135 engine is one of the most powerful fighter engines ever produced and is central to the F 35’s performance, survivability, and mission flexibility. Local final assembly capability reduces reliance on external supply chains and improves resilience during crisis or high operational tempo scenarios.
Pratt and Whitney has emphasized that distributed sustainment across partner nations is a core element of the global F 35 enterprise, ensuring fleet availability while lowering long term operating risk.
Role of Patria in Finland’s Defense Industrial Base
Patria already plays a major role in Finland’s defense aviation ecosystem, with decades of experience in aircraft maintenance, repair, and overhaul. The addition of F135 engine final assembly further expands its technical portfolio and positions the company as a critical node within the global F 35 sustainment network.
According to Patria, the agreement will create high skill jobs and deepen domestic expertise in advanced propulsion systems. The company has also highlighted the importance of knowledge transfer and long term workforce development associated with the Finland F 35 engine assembly program.
This effort aligns with Finland’s broader defense industrial policy, which prioritizes sovereignty, readiness, and secure access to essential military capabilities.
Pratt and Whitney’s Global F135 Sustainment Strategy
Pratt and Whitney continues to expand its international sustainment footprint as the global F 35 fleet grows. More than a dozen countries now operate or have ordered the aircraft, with global flight hours increasing steadily year over year.
The company views partner nation industrial participation as essential to sustaining the fleet at scale. Final assembly and maintenance work performed outside the United States helps balance workload, improve turnaround times, and strengthen allied interoperability.
The Finland agreement complements other regional F135 sustainment hubs across Europe and the Asia Pacific, reinforcing the resilience of the overall F 35 propulsion enterprise.
Finland’s HX Program and Strategic Context
Finland selected the F 35A Lightning II in 2021 to replace its aging F A 18 Hornet fleet, citing survivability, sensor fusion, and alliance interoperability as key decision factors. The HX Fighter Program represents one of the largest defense procurements in Finnish history.
The inclusion of F135 engine final assembly in Finland supports Helsinki’s requirement for national security of supply, particularly given the country’s geographic proximity to Russia and its recent accession to NATO.
Ensuring domestic access to propulsion system expertise reduces operational risk and enhances Finland’s ability to sustain high readiness levels independently if required.
Implications for NATO and Regional Defense
Finland’s growing role in F 35 sustainment has broader implications for NATO’s northern flank. As more European allies field the F 35, distributed sustainment capabilities improve collective readiness and reduce single point dependencies.
Local F135 engine assembly also supports rapid recovery of aircraft during extended operations, contributing to alliance air power resilience in the Baltic and Arctic regions.
Timeline and Next Steps
Patria and Pratt and Whitney have not disclosed detailed timelines for initial assembly operations, but the work is expected to align with Finland’s F 35 delivery schedule later this decade.
Preparatory investments in facilities, tooling, and workforce training are already underway as part of the broader industrial participation package associated with the HX program.
Once operational, the Finland F 35 engine assembly capability will remain in place throughout the aircraft’s projected service life, which extends well into the 2060s.