History of the F135 Engine
Twenty years ago, after extensive competition, the Pentagon awarded a contract to develop the Joint Strike Fighter—a common airframe platform that supports unique missions and meets the requirements of legacy programs while benefitting from common maintenance, training, and supply chains. Similarly, there was extensive competition to develop the aircraft’s engine—one that would be interoperable for all variants of the plane.
In 2009, Pratt & Whitney delivered the first production version of the F135 engine, and in 2011, a broad, bipartisan majority in Congress voted to end a long-standing earmark for an alternative engine. Today, the F135 is the world’s most advanced fighter engine with proven readiness and reliability.
Evolved from the F119 engine that powers the F-22 Raptor and built upon decades of combat-proven propulsion experience, the F135 is a prime example of modern engineering. At the same time, the production costs of the F135 engine have decreased by 50 percent.
In 2023, the Department of Defense selected Pratt & Whitney’s F135 Engine Core Upgrade (ECU) to modernize the F-35 propulsion system and deliver the durability and performance improvements to enable Block 4 capabilities and beyond on all F-35s starting in 2029. The next year, Congress fully funded the ECU in the FY2024 Defense Appropriations bill and included language preventing government funds from being used to develop an alternate engine for the F-35.
The Engine Core Upgrade
The F135 Engine Core Upgrade (ECU) builds on the proven architecture of the existing F135 fighter jet engine in the form of a block upgrade. This is the most cost-effective, lowest risk modernization solution for the F-35.
- Derived from the safest, most reliable fighter engine ever produced
- Fastest schedule to field meaningful capability
- Only variant-common modernization solution
- 10s of billions in lifecycle cost savings for the F-35 program
- Capability to enable Block 4 upgrades
