A mandrel for manufacturing a unitary seamless section of an aircraft fuselage comprises a thin lay-up mandrel element disposed onto the outer shell surface of an inner mandrel shell, forming a mandrel with a substantially continuous lay-up surface. A unitary pre-cured section of an aircraft fuselage is formed by laying up a plurality of resin impregnated skin fibers onto the mandrel's lay-up surface while the mandrel rotates.