F-35's F135 Engine to Get First Full-Scale 3D-Printed Structural Case by 2028

From Prototypes to Certified Flight Hardware

Additive manufacturing has long been used for small aerospace brackets and ducts. Now RTX's Pratt & Whitney and GKN Aerospace are pushing it into the heart of a fighter jet. The two companies have partnered to develop a large, additively manufactured structural component for the F135 turbofan — the engine that powers the F-35 Lightning II — with the goal of certifying it by the end of 2028.

The plan calls for a full-scale demonstrator to be built a year earlier, in 2027, before the program moves into qualification and certification work through 2028. Norway's Defence Materiel Agency (NDMA) is supporting the development effort.

The Hard Part: A Load-Bearing Engine Case

GKN Aerospace will lead the engineering from its facility in Kongsberg, Norway, manufacturing the demonstrator using its laser-directed energy deposition with wire (L-DEDw) process — a method that deposits molten metal layer by layer to build large components.

Structural engine cases are a different beast from the smaller parts already made by AM. They must withstand extreme temperatures, high mechanical loads, and tight dimensional tolerances without hurting engine performance. Crucially, the partners intend the printed case to be fully interchangeable with parts already used across the F135 fleet — no engine redesign required.

"Engineers will not redesign the engine for the project," the companies note. Instead, the aim is to prove that additive manufacturing can deliver an equivalent component capable of meeting the program's certification requirements — a demonstrator scheduled for completion in 2027 ahead of qualification through 2028.

Why It Matters

If successful, the program would mark one of the first times industrial-scale metal 3D printing is certified for a structural, flight-critical engine component on a frontline fighter — not just a prototype or a non-load-bearing part. For the defense additive-manufacturing sector, qualifying a full-scale engine case would validate AM as a route to supply-chain resilience and potentially faster, cheaper production of hard-to-forge large structures.

It also signals where the technology is heading: beyond brackets and nozzles, into the load-bearing core of military propulsion. GKN's original announcement is available via its newsroom, with further detail from Interesting Engineering.