Abstract: An aerodynamic low drag structure (12) has a skin (18, 19, 20) which in movement of the structure (12) relative to a surrounding gaseous fluid medium produces at a flow control region of the skin (18) laminar flow in a boundary layer adjacent the skin. To improve boundary layer control, gaseous fluid is withdrawn from the boundary layer at the flow control region into a first inlet opening (21, 22, 23) in the skin (18) and is conveyed along a first fluid flow path (241, 242) within the structure (12) for discharge at a discharge opening (28) downstream of the first inlet opening (21, 22, 23). Gaseous fluid is withdrawn at a second inlet opening (26) in the skin (20) at a region of the skin subjected to gaseous fluid at ramming pressure and conveyed along a second fluid flow path (27, 242) within the structure to the discharge opening (28) or a further discharge opening.