Shear Web Basics—Proper Wood Grain Orientation

When a wing flexes upward relative to the airframe, as might happen when pulling out of a dive, or in a tight inside loop, the lower wing spar is under tension (stretching forces) and the upper spar is under compression. Shear webs are the most efficient structure for reinforcing the two spars and distributing the loads. Shear webs can be glued to the outer faces of the spars or carefully mounted and glued between them....