Faster and Farther with Growth Option 1.0

The challenge is not an easy one. How do you make the world's most advanced fighter engine, Pratt & Whitney's F135, even better? Engineer Dr. Steven Burd is part of a team doing just that.

"The F135 engine is an outstanding engine," said Dr. Burd. "It is providing capability for all variants of the F135 and meeting the requirements that are needed."

Now, Pratt & Whitney is looking ahead to the future needs of all F-35 warfighters. With follow-on modernization upgrades planned for the F-35 weapon system, an F135 propulsion upgrade can help ensure the F-35 continues to go above and beyond any potential threat.

"As you look to the future and the requirements, this product line is looking for more capability in terms of range and thus fuel burn and thrust," added Dr. Burd.

Pratt & Whitney recently completed performance testing on its Fuel Burn Reduction demonstrator engine at its test facility in West Palm Beach, Florida. This development engine leverages a suite of compressor and turbine technologies developed through the Navy-sponsored F135 Fuel Burn Reduction and Air Force-sponsored Component and Engine Structural Assessment Research (CAESAR) technology maturation programs.

The results are exciting.

This growth option configuration for the F135 engine provides a 5 to 6 percent fuel burn improvement and a 6 to 10 percent thrust increase across the F-35 flight envelope. It can also enable up to a 5 percent powered lift thrust increase for the F-35B variant with modifications to the lift-fan.

"The main thrust here is improving the mission weighted fuel burn of this engine," said Gus McGrath, program chief engineer. "We've put in a package of advanced aerodynamics in both the compressor and turbine, shooting for a five percent reduction in fuel burn and we pretty much achieved that goal."

The configuration is called "Growth Option 1.0," a variant-common upgrade package for the F135 engine that limits hardware changes to just the power module. (The power module consists of the compressor, combustor, and turbine.) With only the power module affected, this means Growth Option 1.0 can be seamlessly integrated into the global fleet of F-35s, either retrofitted during routine overhauls or cut into production at no impact to delivery schedule. The upgrade is also fully compatible with existing F135 sustainment infrastructure.

"To swap out a power module is really straight forward. It's not a big deal, it's pretty easy to do at any point in the engine's life," said Mike Aviles, a test engineer based in West Palm Beach. "It's insertable into any of the variants. You could put it in any time and it will basically give you a step change in fuel burn decrease and increase in performance."

Growth Option 1.0 for the F135 engine provides a low-cost, low-risk path forward that can bring increased capability into the hands of all participants in the F-35 program by the early 2020s.

The proposed upgrade also represents a prime example of Pratt & Whitney's spiral approach to next generation adaptive technologies, enabling the insertion of these advanced technologies into current and future fighter engine platforms.

"As we look to the future, the next generation of air superiority is looking for engines that have adaptive capability – and many of the capabilities demonstrated here," Dr. Burd said.