Kelvin,...

If I remember correctly, the Dirty Birdy as shown on the RCM plans is very complete and well built. In fact I'd go so far and say it is over built. I am referring to the amount and thickness of wood called for in the plans.

Several times I've contemplated building this plane with "lightening" modifications. It is just my personal opinion but I don't believe a plane that size needs 3/16" balsa sides. I would be just as happy with 1/8" contest balsa sides, and either 1/8" balsa or light ply doublers in critical areas. Of course the fuselage formers would be widened to keep the overall width the same.

Also, I was a bit squeamish over the 3/8" balsa top block, I think this could be reduced to 1/8" top with 1/2" triangles in the corners. Of course the balsa side pieces would have to be that much taller to keep the overall fuselage height the same.

All in all, I think the Dirty Birdy is a great airplane and I applaud your efforts to build one. Just keep it light and remove or reduce unnecessary wood if possible.

Please keep me posted on your progress and any modification you decide to make. I'm extremely envious that you're building the plane I've wanted for so long, ha!!

Sincerely,
Steve T.

P.S. What engine are you planning on powering this Dirty Birdy with??