Pratt & Whitney and GKN Aerospace to 3D Print Large-Scale F135 Engine Case

Aerospace Giants Bet on Additive for Military Engine Production

In a move that could reshape how military aircraft engines are manufactured, Pratt & Whitney and GKN Aerospace have announced a Technology Development Agreement to explore the use of additive manufacturing for large structural components of the F135 engine — the powerhouse behind the F-35 Lightning II stealth fighter.

The agreement, announced at the Farnborough Air Show, is supported by the Norwegian Defence Materiel Agency (NDMA) and aims to produce a full-scale, large-format engine case using metal 3D printing. If successful, this would represent one of the first large-scale additively manufactured structures in military aero-engine applications.

Laser-Directed Energy Deposition with Wire

Development will take place at GKN Aerospace's facility in Kongsberg, Norway, using the company's laser-directed energy deposition with wire (LMD-w) process. This metal AM technique uses a high-powered laser to melt feedstock wire as it is deposited, building up complex geometries layer by layer.

The goal is ambitious: produce a full-scale component that maintains compatibility and interchangeability with the current engine design. This means the 3D printed case must meet the same rigorous performance, safety, and certification standards as traditionally manufactured counterparts.

Timeline: Demonstrator by 2027, Certification by 2028

The partners have set a clear roadmap. A first demonstrator component is expected to be ready by 2027, with full product certification targeted for the end of 2028. The F135 engine currently powers all three variants of the F-35 — the F-35A, F-35B, and F-35C — making any manufacturing innovation in its production highly significant for both military readiness and cost efficiency.

Industrializing Additive for Demanding Applications

"This initiative reflects our ambition to further develop and industrialise additive technologies for demanding aerospace applications," said Sébastien Aknouche, Senior Vice President at GKN Aerospace.

Chris Johnson, vice president of the F135 Program at Pratt & Whitney, added: "This agreement reflects our continued focus on advancing technologies that support the long-term needs of the F135 program. We appreciate the collaboration with GKN Aerospace as we explore new manufacturing approaches that contribute to future engine readiness."

What This Means for the Industry

Traditional manufacturing of large engine cases involves extensive machining from solid metal billets, a process that is both material-intensive and time-consuming. Additive manufacturing promises to reduce waste, shorten lead times, and enable design optimizations that are impossible with subtractive methods.

If the project succeeds, it could pave the way for broader adoption of metal AM in military engine production, potentially extending to other engine platforms and components. The F135 program has already been a testing ground for additive manufacturing — Pratt & Whitney has previously incorporated 3D printed parts into the engine — but scaling to full engine cases represents a significant leap in both size and structural complexity.

With global demand for the F-35 expected to continue through the 2030s, innovations in manufacturing efficiency could have substantial financial implications for both Pratt & Whitney and its supply chain partners.