Abstract: A plurality of channel-shaped members (12) are positioned longitudinally along the inner surface of an outer skin (6). Each member (12) has a web (14) and two flanges (16). Members (12) are positioned laterally contiguously to each other so that, when outer skin (6) and members (12) are cured together, webs (14) form an inner skin portion (8) and adjacent flanges (16) form blade stiffeners (10). A generally L-shaped member (22) is positioned to extend longitudinally along the inner surface of outer skin (6) adjacent to each side edge of skin (6), with one leg (26) of member (22) contiguous to a modified flange (16') of channel-shaped member (12'). When outer skin (6) and members (12,12',22) are cured together, leg (26) and flange (16') form a spar chord (20). Reinforcing fibers in skin (6,8) resist torsional shear. Reinforcing fibers in stiffeners (10) and spar chords (20) resist bending loads.

Abstract: A graphite containing composite structure having a fastener area for joining the composite to other structures terminates the graphite reinforced laminate adjacent to the fastener area. Kevlar reinforced laminates abut the graphite laminate and extend over the fastener area and are further reinforced with Kevlar laminates that overlap the graphite then extend over the fastener area.