Abstract: A rigid airship is disclosed herein having an annular or toroidal airfoil fuselage in front elevation for housing several elongated gas cells containing a buoyant gas such as helium. The fuselage includes at least two longitudinal and a plurality of transverse structural members for supporting the cells. A covering is provided about the fuselage comprising a multiplicity of fitted panels joined by retainer straps and locking nodes. The fuselage defines a central venturi having an annular intake and a contracted exit through which an elongated tapered tail cone extends in coaxial relationship with the fuselage. Boundary layer control is effected via manifolds associated with the fuselage panels and a variable geometry venturi passageway is effected by longitudinal movement of a control compartment and adjoining tapered tail cone.