VHF NAV Transfer Switch
Should either VOR receiver fail, the VHF NAV transfer switch enables selection of the
opposite VHF NAV receiver for display.
IRS Transfer Switch
Should either IRS fail, the IRS transfer switch is used to switch all associated systems to the
functioning IRS.
FMC Transfer Switch
Positioning the FMC Source Select Switch to BOTH ON L or BOTH ON R isolates FMC
operation to use only the left or right FMC respectively. In the NORMAL position, the left
FMC is primary by default. Although the crew can enter information into either CDU, the
primary FMC is responsible for synchronizing this information with the secondary FMC and
updating both CDU displays.
