An actuator assembly is provided comprising a data transfer head moved by an actuator arm in a data storing and retrieving relationship with a data storage medium. Streamwise arranged aerodynamic fluid re-directing and drag-reducing features on a surface of the actuator arm modify frictional forces acting on the arm from a fluid flow created by moving the medium. A method is provided for improving nonrepeatable runnout disturbances in a data storage device by aligning the drag-reducing features of the actuator assembly with a direction of a mean flow direction of the fluid at an outer diameter of the storage medium to divert the fluid flow away from the head gimbal assembly.