P-39 Airacobra Progress October 2026

We are very close to finishing the P-39 Airacobra project at Planes of Fame. Here are the latest pictures from the restoration, along with some related 3D-printing developments for the trim tab, aileron, and rudder dials.

Many of the control panels were built from scratch from the original blueprints and developed in CAD. The Control Panel was derived from a combination of blueprint data in conjunction with the maintenance manual datasets. The actual blueprint for this model does not exist, so the various elements required extensive research to get this right.

The Gunsight mount is one area where 3D printing proved invaluable in the development of these parts. We didn’t have all the variant data for this particular model, so again we researched from known data sources and dimensional information to create an accurate replica. The mounting mechanism and plates were first 3D-printed and then test-assembled before committing to actual machine-shop fabrication.

I mentioned above the Trim Tab dials for the Rudder and Aileron. I actually 3D printed these here in the UK to determine what is viable for 3D printing and what needs to be fabricated. Ideally, a working prototype would be nice but not essential. The first set of images is the breakdown of parts from the CAD model, with the last image showing the 3D composite model.

All 3D-printed parts for this exercise were done with a 0.4mm nozzle and a layer height of 0.12mm. The model’s finish is actually surprisingly good. A smaller nozzle of 0.2 mm would permit a smaller layer height of 0.08 mm, thus yielding even better results.

Some of the smaller parts, like the small gears, were okay but not sufficiently detailed to create a working model. These could, of course, be machined and assembled in conjunction with 3d printed parts, which would, in fact, work well for prototyping. This was a demonstration of what can be accomplished with 3d printing and also outlined the limitations. It will be interesting to see what Planes of Fame decides to do to complete the Trim Tab console.

I shall post new updates as they become available. I can honestly say it has been a privilege and a challenge to work on this P-39 project.

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