CDU Pages Tour

Step-by-step: CDU Pages Tour

1. You start on IDENT. Navigate to RTE to see where the flight plan lives.

   RTE (Route) is where you enter origin, destination, and the route between them. After IDENT, this is the first page every flight visits. Companies that use saved company routes type the route code here; otherwise you build the route on LEGS.

2. Go to the PERF INIT page. PERF INIT holds the performance setup.

   PERF INIT (Performance Initialisation) is where you enter cruise altitude, cost index, zero fuel weight, and fuel reserves. The FMC needs all of this before it can compute trip fuel and predictions. Required before takeoff.

3. Go to the LEGS page. LEGS shows each waypoint of the route with predictions.

   LEGS is the in-flight version of the flight plan — every waypoint with altitude and speed constraints, and predicted ETA / fuel at each one. ATC reroutes are entered here. This is the page you look at most after departure.

4. Open the MENU page. MENU is the FMC system index.

   MENU is the FMC system page — it lists every subsystem the CDU can talk to (FMC, ACARS, MAINTENANCE). On the ground you use it for the FMC self-test. In flight you rarely need it, but knowing where it lives means you can return to a known state if you get lost in nested pages.

5. Return to the IDENT page to complete the tour.

   The CDU has more pages than these five — DEP/ARR, HOLD, N1 LIMIT, FIX, PROG — but you can fly a complete flight using just the five you have just toured. Master these first; the others are extensions.