Closure devices and methods are provided for closing a stringer penetration space defined between a stringer and a wing rib of an aircraft wing section. According to certain embodiments, the closure devices will integrally include a forward face plate positioned in covering relationship to at least a portion of the stringer penetration space, and a rearwardly projecting attachment arm rigidly adapted for rigid attachment to the stringer so as to positionally fix the forward face plate relative to the stringer penetration space.