How come in the 777 you usually see the ADI on the PFD is up while parked at the gate even though the ADIRU is off b/c theres no hdg info on the nav display? is the ADI fed information from a different source than the navigation info? basically im comparing the 777 to the rest of th boeings how the IRS i nthe others is off the ADI goes out too except of course in ATT mode. why is the ADi up on the 777 even tho the ADIRU is off? thank you for replies
http://www.!!!!!!!!!!!!!!/open.file/1196630/L/
http://www.!!!!!!!!!!!!!!/open.file/1059910/L/
Tyler