Leph--
By using "one-sided" objects, you can indeed create a canopy frame that is "semi-transparent" from inside the 3D cockpit, yet "solid" when viewed from outside. You simply make an "inner" and "outer" frame object. Both are "one-sided," i.e. they are visible from one side, and invisible from the other. You make the inner object semi-transparent, and face it inward. It will look like "tinted glass" to the pilot. You make the outer object non-transparent, and face it outward. It will look like the solid canopy frame from outside the plane.
You're right tho: it's a rebuild of the canopy area for every plane...