Phil, here we go again, someone putting out bad info. about something they must not know anything about.........FYI, the LE is 1/2" sq., spars are 3/16" x 3/8", and TE of 1/16" x 1-1/2" top and bottom has been proven on many combat and stunt ships, even today!!! Covered in silk, as in the day it was a tough little plane and built right would never come apart in the air.. I used to have a saying "The only way to produce a perfect kit was to supply a builder in every box". Almost all problems always go back to the builder.........
BTW the Demon was designed to be a very simple to build combat trainer, not a top line winner and as such served it's purpose.. And along the way won a lot more than I expected.... A lot of guys including James Mears and Howard Henry did quite well with them.
RW