I'm thinking about installing my NACA ductwork in my QB wing, and this seems to be another potential pitfall for novice builders such as myself. No mention in the builder's manual, and the instructions that come with the duct kit are purposefully vague. I'm wondering if anyone has installed screens in the inlet of the duct? I know bugs aren't an issue at altitude... but I'm leery of having an unscreened opening that accesses the fuselage. I'm wondering if any other builders have thought of this, and what they might have done.