ESDU 06013 relates the forces acting on a propeller to the characteristics of the far (fully-developed) wake@ both for the axial case and a propeller at incidence or sideslip. Compatibility is shown between blade element theory (propeller forces)@ actuator theory (momentum balance) and the wake model (vorticity). Comparisons of the slipstream deflection in the far wake are made with the predictions of Ribner's early work. Expressions for the development of the slipstream at intermediate stations are related to the conditions in the far wake. The results are illustrated graphically.