737 NG dual FMC failure
Hi,
In the B737MRG there is comment on technique to manage a dual FMC failure airborne. It is mentioned that map mode can still be used and suggests selecting STA and WPT in order to navigate to positions using heading select.
I understand that the MCP modes ( hdg, alt hold, v/s ) are still available as is the auto pilot but I am unsure where the information for stations and waypoints is coming from. I would have thought that this information was in the FMC navigation database and with the dual FMC failure would become unavailable.
Can anyone explain the source of the info assuming dual FMC failure?