Structural panels for use in manufacturing fuselage bodies and other aircraft structures are disclosed herein. In one embodiment, a monolithic integrated structural panel is configured to include a skin, an array of stiffeners and an array of frames which are preferably arranged in a mutually orthogonal layout, without the need of cut-outs in any of the crossing elements. One advantage of the disclosed embodiments is that the frame and stringer members have continuous flanges and spliced webs. The disclosed embodiments herein are compatible with composite materials technology, offering another advantage, namely the possibility of manufacturing integrated products in a single cure ("one-shot") cycle. A structure of composite materials, e.g. carbon fiber reinforced plastics, typically comprises a skin panel, reinforced by frame and stringer members. A monolithic integrated structure constructed in accordance with the disclosed embodiments is well-suited for use as a portion of an aircraft structure, for example an aircraft fuselage, wing or empennage.