1-5190-00601-02 Rev. J Garmin G500/G600 Pilot’s GuideCoverTOCForewordSec 1SystemSec 2PFDSec 3MFDSec 4HazardAvoidanceSec 5AdditionalFeaturesSec 6Annun.& AlertsSec 7SymbolsSec 8Glossary Appendix A Index1.1.1.2 Air Data ComputerThe Air Data Computer (ADC) compiles information from the Pitot-staticsystem and an Outside Air Temperature (OAT) sensor. The ADC providespressure altitude, airspeed, vertical speed, and OAT information to theG500/G600 system. The ADC communicates with the GDU 620 and AHRSusing an ARINC 429 digital interface.Figure 1-4 Air Data Computer1.1.1.3 Attitude Heading Reference SystemNOTE: Aggressive maneuvering while the AHRS is not operating in normalmode may degrade AHRS accuracy.The Attitude and Heading Reference System (AHRS) unit provides aircraftattitude information to the G500/G600 display. The unit contains advancedaccelerometers and rate sensors and interfaces with both the ADC and theGMU 44 magnetometer. The AHRS utilizes GPS data forwarded from theGDU 620. Attitude and heading information is sent to the GDU 620 using anARINC 429 digital interface.Figure 1-5 AHRSThe International Geomagnetic Reference Field (IGRF) model is containedin the AHRS and is updated once every five years. The IGRF model is part ofthe Navigation Database. At system power-up, the IGRF models in the AHRSand the Navigation Database are compared. If the IGRF model in the AHRS isout of date, the user is prompted to update. The prompt will appear after theG500/G600 splash screen is acknowledged on the MFD.
