How do you input or modify a route in the MCDU?

• A. Use the MAP page to insert or modify waypoints.
• B. Use the RTE page to insert or modify waypoints and transitions; use the legs page to adjust leg order or constraints; confirm changes.
• C. Use the PERF page to insert or modify waypoints.
• D. Routes cannot be modified after loading.

Answer: (B)

Editing a flight plan in the MCDU is done primarily on the Route page. This page is where you input or modify waypoints and transitions so the computer’s path between fixes reflects your intended route. After you place or change waypoints on the Route page, you use the Legs page to fine-tune the sequence and any leg-specific constraints like altitude or speed, and to reorder legs if needed. Once those edits are set, you confirm the changes to lock them in.

The MAP page is mainly for display and situational awareness, showing you the route graphically, but it’s not the primary tool for inputting or modifying the route. The PERF page deals with performance data and does not handle routing. And a loaded route can be modified—routing isn’t fixed after loading.