The ADIRU uses six ring laser gyros and six accelerometers to calculate and supply inertial reference and navigation data to user systems.
The air data inertial reference unit (ADIRU) has two functions:
Air data
Inertial reference data.
The ADIRU has internal redundancy and automatically makes allowances for failures to keep its complete function.
The ADIRU has these internal components:
Six laser gyros
Six linear accelerometers
Four processors
Three power supplies
Three dual channel ARINC 629 input/output interfaces.
Secondary Attitude Air Data Reference Unit
The secondary attitude air data reference unit (SAARU) is a back-up source of attitude, heading and air data. The SAARU uses these inputs to calculate and supply air data to user systems:
Pitot pressure
Static pressure
Total air temperature
Angle of attack.
The SAARU uses four fiber optic gyros and four accelerometers to calculate and supply inertial reference data to user systems.
The SAARU supplies attitude data to the standby attitude indicator.