A fault-tolerant air data/inertial reference system

The air data inertial reference system (ADIRS) described consists of a fault-tolerant air data inertial reference unit, a secondary air data attitude reference unit, and six air data modules. The ADIRS replaces the conventional inertial reference and air data systems and uses ARINC 629 bi-directional serial digital data bus interfaces. The ADIRS is designed to be the inertial and air data reference for the ARINC 651 integrated modular avionics (IMA) distributed architecture and provides low life cycle cost and high availability through high reliability, simple high integrity monitoring and deferred maintenance