Abstract: Processes for manufacturing hollow structures such as spars for helicopter rotor blades, fixed wings for aircraft, and other aerostructures can include the provision of a path for gases to exit the material from which the spar is formed as the material is heated and cured, to help eliminate voids within the material caused by the presence of such gases.

Abstract: Processes for manufacturing hollow structures such as spars for helicopter rotor blades, fixed wings for aircraft, and other aerostructures can include the provision of a path for gases to exit the material from which the spar is formed as the material is heated and cured, to help eliminate voids within the material caused by the presence of such gases.

Abstract: A rotor blade, whose principal structural components are of fiber-reinforced composite material, includes a spar, fairing skins, spar wraps, splices and doublers in the precured condition cut from rolls of raw stock into flat sheets having the dimensions of the components in the assembled position and laid one laminate upon another laminate to the desired thickness dimension. A noseblock and trailing edge block are precompacted and formed to desired shapes and sizes in the precured condition. A honeycomb core, formed to the contour of the trailing portion of an airfoil behind the spar, is prepared. Molding tools, one tool having the contour of the upper blade surface and another tool having the contour of the lower blade surface, each tool adapted for assembly together so that their inner surfaces envelop the outer blade surface, are formed and adapted to receive the components of the blade therein.