Position of a feature on a plane perpendicular to the leveling plane

Position of a feature on a plane perpendicular to the leveling plane

Hello to all,

 I am measuring the position of a feature R13, that is perpendicular to the reference frame  A/D.  This is not usual on the part prints I work with.

A .ppt was attached showing what was done, but I would like to hear some comments or corrections.

Thanks in advance,
Juan