Patent ID: 8204635

Claim:
An aircraft inertial system, comprising: at least two inertial reference units (IRU) configured to provide a first set of inertial signal data for operating an aircraft; at least two attitude heading reference systems (AHRS) configured to provide a second set of the inertial signal data for operating the aircraft; at least one primary flight display configured to receive the first and the second sets of the inertial signal data; a standby flight display configured to receive at least the second set of the inertial signal data from at least one of the AHRS; wherein when a single fault condition occurs in the inertial system, the primary flight display continues to operate with fail-operational redundancy from at least three independent sources of the inertial signal data comprising one or more combinations of the at least two IRU and the at least two AHRS; and wherein the standby flight display continues to operate using a different source of the inertial signal data than the source of the inertial signal data for the primary flight display.