It's built in somewhat desperate situation where bonds to U.S.S.R. have cooled down a bit as a punishment for rejecting communism and going with different political ideals. MiG-25 spare parts such as Tumansky R-15 engines, known to wreck themselves in combat were stockpiled for war time use when they might break faster than rebuilding was possible, leaving mighty warplanes grounded.
Ok, but the R-15 is designed for a very specific flight envelope. Any nation will stockpile large amounts of whatever engines all its planes use.
"Steel-skeleton" was a best phrase i could come up with to describe wood construction and steel trusses that hold everything together.
I don't know if that will work.
It's got a "keel" or a backbone that runs through almost all of the airframe and to that steel truss are attached ribs, wings and other parts.
That is exactly how
not to design an aircraft's internal structure. At best you've introduced large internal members that are going to get in the way of the plane's ability to hold things, principally bombs. You can look at a whale skeleton to see what kind of construction that means (i.e., a very big backbone/keel that is going to dictate what the rest of the airplane looks like). Most real, large aluminum airplanes are built like a whale skeleton - but minus the backbone. Now that the skeleton is composed entirely of just the ribs, you have a lot more flexibility in take-off weight and how to actually design the aircraft. Since the ribs are bonded to a very strong exoskeleton, you don't need to worry about the lack of a backbone.
Planes do have a keel of sorts called the main spar but it runs perpendicular to what you're thinking - it's the "backbone" of the
wing and it's what the ribs and stringers for the wing attach to. The shape of the wing (it helps that the fuselage gets much of its structural strength in being tubular) and the relatively lightweight and internal volume of the wing (it's not holding any heavy systems other than engine, hydraulics and fuel and all three of those don't care about what kind of internal volume the wing spar takes up) means it can not only get away with this, it
must.
Wing spars are made of three steel trusses similar to that of back bone and wood ribs are attached to them.
Oh, so you do know what wing spars are, my bad.
Wings are covered with thin plywood sheet skin made of sheets that are only 1,2 by 2,4 meters, an industrial standard size. As a result plenty replacement skin material is easy to get everywhere in Navajanir and damage to skin can be repaired very quickly even by woodworkers who have never touched an aircraft in their life.
Well, I don't know if that's going to work. Yes it's ostensibly the same as the Mosquito but the Mosquito 1.) was operating at a different level of technology 2.) at a different operating environment (different speeds and most importantly at a different scale) and 3.) perhaps most important of all, the Mosquito had a very short shelf-life (if the plane could only last a few sorties, they were making so many it was good enough and they can and did salvage the engines and other parts from the shell for re-use on others if they ended up outlasting the plane). Many if not most Mosquitos simply and literally rotted out due to poor care and storage conditions.
And now that I've mentioned that you're no doubt planning on preventing that with proper care and storage conditions. I can store a wooden, say, Waco biplane in a limited climate-controlled hangar all by myself no problem. Long-term maintenance, however, is very labor intensive. And this is for a small single-engine aircraft that's still in production. For something like this you're pretty much going to do what the USAF does for B-2s now.
And if you think "that's ok, I'll just make more to make up for the attrition", that's going to be a very expensive proposition too.