Foam cutter

[Pistolero]

Structural cores. All primary structure is "sandwich construction" which has glass/epoxy skins bonded to
foam cores. VERY stiff and light. Different core foam densities and polymers for different applications.
The wing cores were hot wired, then the leading edges cut off. A variable depth groove on the top and
bottom of the wing was part of the core shape, and this became to location for top and bottom spar
caps. The cut off face became the connecting shear web, glass/epoxy laid over the aft core's front face (after cutting
off the leading edge), then the leading edge bonded back in place, leaving a vertical shear web wrapped
into the floors of the top and bottom spanwise spar cap grooves. Then spanwise glass unidirectional tapes
were laid in these grooves, building a "C" beam of fiberglass embedded into the foam core. Finally, the
skins were applied, essentially making the foam cores a full span "rib" supporting the skins and stabilizing
the "C" beam spar.

If that isn't clear (and I suspect it may not be) I can add sketches if you actually care. May already be
far past the "too much info" point.

Bill

 

[Ian]

No worries, Bill, Boeing signed my checks for a few years and I chat with some of the guys from Mooney from time to time (we service some of their equipment), so I'm familiar with the concepts, just not the foam/glass methods of executing them.

 

[Pistolero]

OK, the short version is a solid foam core for the aerosurfaces with no spars in the winglets,
skins are strong enough, C spar embedded in the canard and main wings. Fuselage is flat
sheets of foam, skin inside and join, then round corners (wood stringers at corners) and
add exterior skin. Engine mount is steel, gear legs premade solid glass/epoxy.

Bill