Give me the number of the 787 print that calls out Maple, Plywood, or MDF, for a structural part and I'll wire you a fat load of cash! I like the GP-4 but it is neither certified nor has it ever been in production commercially. It is labor intensive to build and could be made more efficient with a more modern type of construction. The kit says it comes with "all the metal parts prefabbed." Needless to say it is a good example of why most kit builders select a different type of construction.
Wow. Nice creds. Maybe we work together. My point was not that wood is comparable to CFRP etc, it was simply that wood is one of many composite products available that have different qualities and applications. IMHO, as an astronaut/jillionaire/male-model/tycoon/FBI Fighter pilot Evaluator/syndicated cartoonist/semi-pro nose-tweeker.