Systems, methods, and machine-executable programming products adapted for the control of aircraft or other vehicles by receiving from at least one Inertial Reference System (IRS), including a plurality of Inertial Reference Units (IRUs), signals representing vehicle state data; receiving from at least one Augmented Direct Mode Sensor (ADMS) signals representing independently-acquired vehicle state data corresponding to at least a subset of the signals received from the IRS; performing signal selection and fault detection processes on the signals received from the at least one IRS and on the corresponding signals received from the ADMS; based at least partly on the signal and fault detection processes, determining whether at least one component of at least one of the IRS and ADMS is in a fault condition; and based on the fault condition, providing to at least one vehicle control system device one or more vehicle control command signals.