Abstract: A load-bearing composite material structure (2, 2') has a plurality of layers of composite material. Each layer includes a matrix material (4) that maintains its structural integrity at 1200.degree. F. for at least five minutes. Preferred matrix materials are polyimide resins. Outer layers that will be directly exposed to a fire are reinforced with a woven fabric (8) that is sufficiently flame resistant and has a sufficiently fine weave to prevent flame penetration at 2000.degree. F. for at least fifteen minutes. The woven fabric (8) is preferably ceramic. The rest of the layers are reinforced with a fibrous material (6) to provide the necessary structural strength. The layers may be laminate cured together to form a single, integral structure (2) or such laminates adhesively bonded to a honeycomb (12).

Abstract: A load-bearing composite material structure (2) includes a first ply (10) of fiber reinforced composite material, and an integral blanket (20) for thermal and flame protection. Blanket (20) includes an outer flame resistant face sheet (28), an intermediate layer of insulation fill (26), and an inner face sheet (22). Sheet (22) is formed by a second ply of fiber reinforced composite material. Preferably, a thin film (24) is provided between ply (22) and fill (26) to prevent absorption of matrix material into fill (26). The layers (22, 24, 26, 28) of blanket (20) are stitched together with flame resistant thread (30). Plies (10, 22) are cured together to bond them together and integrate blanket (20) into structure (2).