Present novel and non-trivial systems and methods for validating single-channel tactical flight data in a multi-channel architecture are disclosed. Three single-channel monitors are disclosed along with a fourth, external monitor that is accessible to the multiple channels. A system could be comprised of a navigation data source, two or more communications channels, and an external display unit (“DU”), where each channel may be comprised of a flight management system (“FMS”), a DU, and a flight director (“FD”) system. In addition to the FMS performing two standard functions of calculating a lateral deviation (“LDEV”) and a roll command (“Roll Cmd”), a second LDEV/Roll Command calculator and a Roll Command Calculator are employed in DU and FD of same channel, respectively, to determine data validity. In addition, the FD and the symbologies of LDEV and Roll Cmd generated by the DU are also employed in the determination of data validity.