Simulated outflow profiles for outflow inclinations with respect to our line of sight of 10° (upper) and 90° (bottom). The outflow velocity in this particular simulation increases up to a turnover radius and then decreases. Up to four different velocity fields are considered in Appendix A. The magenta curve shows the outflow component, the grey curve the systemic component and the black curve the total profile. The vertical dashed lines show the flux-weighted v_out measured from the total profile at |v|≥300 km s⁻¹ (coloured in blue and red). The vertical solid lines show the flux-weighted v_out measured from the outflow component over the full velocity range. For high outflow inclination (close to the plane of the sky), the contribution to the outflow flux by the gas at low projected velocities (|v|< 300 km s⁻¹) increases.