Illustration of a jet–megamaser disk system and its orientation with respect to the observer line of sight, as seen by projection angles. The jet direction (assumed to be aligned with the MBH spin $\widehat{s}$) is denoted $\widehat{j}$, while the megamaser plane is defined by its normal vector $\widehat{m}$. Its projection onto the sky plane is described by the angle PA_mm. The megamaser disk in the figure is close to edge-on, as in our reference model. The corresponding projection of the jet direction is denoted by the angle PA_j. For clarity, angles and vectors lying on the sky plane are shown as gray segments and arcs.