Speed & Altitude Constraints (VERT REV)
intermediateEnter a crossing altitude constraint on the A320 MCDU. Learn the vertical-revision workflow — right-select a waypoint on the F-PLN to open VERT REV, then enter the constraint the FMGS must meet.
Start this scenario
Open the SimTuts A320 MCDU trainer and select “Speed & Altitude Constraints (VERT REV)” from the scenarios list to walk through it step-by-step on the simulated keypad.
Open trainer →Step-by-step: Speed & Altitude Constraints (VERT REV)
- Enter a route. Type EGLL/LFPG into the scratchpad and press 1R.
This seeds a route with a discontinuity between EGLL and LFPG — we will close it with a waypoint, then put a constraint on that waypoint.
- Press F-PLN to open the flight plan.
Constraints are entered per waypoint on the flight plan, so we work from the F-PLN page.
- Close the gap so there is a waypoint to constrain. Type DVR into the scratchpad and press 2L (the discontinuity line).
DVR (Dover VOR) is now an enroute waypoint between EGLL and LFPG — exactly the kind of point you would cross at a charted altitude.
- Open the vertical revision for DVR. Press 2R — the RIGHT line key next to DVR.
On the real A320, a LEFT line-select opens LAT REV (lateral — routing); a RIGHT line-select opens VERT REV (vertical — speed and altitude). This is the page where crossing constraints live.
- Enter a crossing altitude. Type FL100 into the scratchpad and press 1R (ALT CSTR).
ALT CSTR FL100 tells the FMGS to cross DVR at 10,000 ft. It now feeds the descent/climb profile and the predictions. A constraint shown in magenta is one the FMGS predicts it will meet; an amber one would warn it expects to miss it — which you fix by managing the energy state (speed/speedbrake), not by retyping the altitude.