A Liquid Resin Infusion (LRI) fabrication process is presented for manufacturing of composite aircraft demonstrators. A Building Block (BB) assessment approach is adopted, structured in coupon, element and subcomponent level. The quality of fabrication is quantified in terms of porosity and fiber volume fraction and the properties of the composite ply are determined by means of micromechanical models and coupon mechanical tests. At element and subcomponent level, an aft-fuselage bulkhead joint and a floor beam are modeled and tested in full scale. Results provide a measure of process capabilities and parts quality, indicating low void content and stiffness comparable to a similar prepreg.