This invention provides a coupling method for coupling a first and a second stiffening profile element for an outer skin of an aircraft or space craft. In a first step the stiffening profile elements are arranged on the outer skin in such a manner that the stiffening profile elements oppose each other with their respective front sides and enclose within themselves a cavity. Furthermore, a fixing hole is formed through a wall of at least one of the stiffening profile elements in the cavity inside a coupling zone of the stiffening profile element. An access opening is formed through the wall in the cavity along the coupling zone. A coupling strap, which couples the stiffening profile elements together, is fastened to the coupling zone by means of a fastening element guided through the fixing hole.