Pratt & Whitney and GKN Aerospace Will 3D-Print the F135 Engine Case

Key takeaways

Pratt & Whitney (RTX) and GKN Aerospace have signed a Technology Development Agreement to explore additive manufacturing of a large structural case for the F135 engine — the powerplant of the F-35 Lightning II.
The work will be led from GKN Aerospace’s Kongsberg, Norway facility using its laser-directed energy deposition with wire (L-DED w) process, and is backed by the Norwegian Defence Materiel Agency (NDMA).
The goal is a full-scale part that stays interchangeable with today’s cast-and-machined design — likely among the first metal AM structures of this size in a military engine.
Timeline: a demonstrator by 2027 and a certified product by the end of 2028.
Announced at the 2026 Farnborough Air Show, the deal is pitched as a way to cut lead times, reduce material waste, and harden the F-35 supply chain.

Two of aerospace’s biggest names want to grow one of a fighter jet’s most demanding parts layer by layer. On July 20, RTX’s Pratt & Whitney and GKN Aerospace announced a Technology Development Agreement to jointly explore using additive manufacturing (AM) to produce a large structural case for the F135 — the engine that powers every variant of the F-35 Lightning II. The news broke during the Farnborough Air Show and was confirmed by TCT Magazine and VoxelMatters.

What’s actually being printed

Engine cases are big, load-bearing shells that hold the guts of a turbofan together and carry flight loads — exactly the kind of certified structural hardware that has historically been forged, cast, or machined from billet rather than printed. That’s what makes this program notable: the partners aren’t printing a bracket or a fuel nozzle, but a large-scale case that has to match the “performance, compatibility and interchangeability” of the current F135 part. If it works, GKN says it would be among the first metal AM structures of this scale to reach a military engine.

The build will run at GKN Aerospace’s site in Kongsberg, Norway, using the company’s laser-directed energy deposition with wire (L-DED w) process — a technology GKN has matured over several years. Wire-fed DED melts metal wire with a laser and stacks it into near-net shapes, which suits large parts far better than powder-bed fusion: it deposits material quickly and skips the giant powder vats that big components would otherwise demand. The Norwegian Defence Materiel Agency is supporting the joint development programme.

Why it matters

The pitch is part performance, part logistics. Additive manufacturing can compress lead times, cut buy-to-fly material ratios, and simplify long, fragile supply chains — a growing priority as the F-35 fleet expands and sustainment costs stay under scrutiny. Growing a case near-net from wire means far less expensive titanium or nickel alloy ends up as machining chips, and a printable digital part is easier to surge or relocate than a forging that depends on a handful of presses worldwide.

“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, framed it as “advancing technologies that support the long-term needs of the F135 program” and “future engine readiness.” It also builds on GKN and Pratt & Whitney’s decades-long F135 relationship and GKN’s recent move to expand its AM capacity in Norway.

The catch: it’s a demonstrator, not a fielded part

Worth keeping expectations grounded — this is a feasibility program, not a printed case bolting onto jets tomorrow. A first demonstrator component is targeted for 2027, with a certified product expected by the end of 2028. Structural engine hardware faces some of the most punishing qualification in aerospace, and DED parts still need extensive inspection, heat treatment, and machining before they can be trusted with flight loads. Still, putting a certification date on a part this size signals real confidence, and it lands amid a broader defense push into large-format metal AM. If the 2028 milestone holds, it becomes a reference point for printing big structural aero-engine parts well beyond the F-35.

FAQ

What engine is being 3D printed?

Not the whole engine — a large structural case for the Pratt & Whitney F135, the turbofan that powers the F-35 Lightning II. The rest of the engine is unchanged; the program targets one big load-bearing component.

What 3D printing technology are they using?

GKN Aerospace’s laser-directed energy deposition with wire (L-DED w), running at its Kongsberg, Norway facility. Wire-fed DED is well suited to large near-net-shape metal parts.

When will a 3D-printed F135 case be ready?

A demonstrator is targeted for 2027 and a certified product by the end of 2028. This is a development program, so timelines can shift as qualification progresses.

Why print an engine case instead of forging it?

Additive manufacturing can shorten lead times, cut material waste, and make the supply chain more resilient than tooling-heavy forging or casting — valuable for a globally fielded fleet like the F-35.