The U.S. Department of Defense announced on August 22, 2025, that Pratt & Whitney Military Engines, a division of Raytheon Technologies, has been awarded a $2.9 billion undefinitized contract modification for the production and delivery of 141 F135 propulsion systems supporting Lot 18 F-35 aircraft. The deal covers the Air Force, Navy, Marine Corps, F-35 partner nations, and Foreign Military Sales customers, with completion expected by February 2028.
The F135 engine, capable of delivering up to 43,000 pounds of thrust, powers all three F-35 variants: the conventional takeoff F-35A, the carrier-based F-35C, and the short takeoff/vertical landing F-35B. Beyond complete engines, the contract also provides spares, tooling, program management, and engineering support to sustain global fleet readiness.
To date, over 1,300 F135 engines have been delivered to 20 allied nations, making it the backbone of the Joint Strike Fighter program and a key enabler of allied interoperability. The engine program also supports the U.S. economy, with more than 240 suppliers contributing and over 67,000 American jobs tied to its production, generating $9.1 billion in economic output in 2024 alone.
Technically, the F135 is an advanced afterburning turbofan derived from the F-22’s F119, modified for the F-35’s broad mission set. For the F-35B, it integrates Rolls-Royce’s LiftSystem, enabling vertical flight. The engine includes stealth features such as radar-absorbing coatings and a sawtooth exhaust nozzle, while modular design and onboard diagnostics simplify maintenance.
Although alternatives like the GE/Rolls-Royce F136 and GE’s XA100 adaptive engine were explored, the Pentagon opted to continue investing in the F135 through an Engine Core Upgrade, citing cost efficiency and compatibility across all F-35 variants.
This latest $2.87 billion award ensures that the F-35 fleet maintains a proven, combat-ready propulsion system, securing U.S. and allied dominance in contested airspace well into the next decade.
