Abstract: The disclosed semi-buoyant lift-augmented aircraft, preferably of immense size, includes a fuselage of airfoil shape formed by a rigid geodesic type web framework enclosing buoyant cells pressurized to reinforce the framework. Wings are provided which impart aerodynamic lift to the aircraft, with the airfoil fuselage. The buoyancy is provided to counteract a major proportion of the great weight of the structure and to thus improve the aircraft's payload capability and range. These features maintain it airborne at reasonable speeds over a substantial altitude range.