A fluid-flow machine includes: a main flow path boundary and at least one row of relatively rotating blades with a gap existing between blade ends and the main flow path boundary. At least one secondary flow duct having one opening each is provided in the main flow path boundary at ends spaced apart in the flow direction, such that the secondary flow duct is connected to the main flow path via the two openings. The structural assembly has at least one support component and at least one insertion component. The support component includes a recess extending in the circumferential direction that receives the at least one insertion component such that the support component surrounds the at least one insertion component largely on its sides not facing the main flow path, and where the insertion component completely surrounds or forms at least one secondary flow duct.