Navigation database

The MCDUs have separate screens and scratchpads, but FSS says they share one flight plan. A change made on one unit can affect what the other pilot sees.

Open NAV IDENT

After power-up, show NAV IDENT once before using the main route and performance functions. Check the navigation database cycle, date and UTC.

Enter a value

Enter the required cycle or date in NAV IDENT. Press the line-select key beside each field, then read the inserted value.

Understand MOD

A route edit creates a temporary MOD plan. Inspect the map and legs before ACTIVATE. CANCEL discards the pending MOD plan, including any other edits in it.

Review the active plan

On FPL use PREV and NEXT to page through the legs. Compare runway, procedure, transitions and constraints against the current clearance and charts.

Make a direct-to

With an empty scratchpad, use the left line-select key beside the target fix. Review the proposed track and activate the modification when appropriate. There is no separate DIR key in the documented FSS unit.

Changing a waypoint is not the same as changing the navigation source or engaging LNAV. Confirm the route, source and FMA separately. ^{[19, 20]}