When any other flightplan (Missed Approach, Alternate, Temporary, Secondary) except the Primary flightplan is depicted on the ND in an Airbus A320 and the CSTR (constraint) button is pressed on the EFIS, will constraints for both flightplans be displayed on the ND?


1 Answer 1


No, just the active flight plan.

Those constraints are part of the pseudo-waypoints, which are predictions that are only displayed for the active flight plan.

The system calculates various predictions for the active flight plan and updates them continually during flight (...) The MCDU and the ND show these predictions, each of which is based on specific assumptions.

(A320 FCOM)

  • $\begingroup$ You are correct that constraints for non-active plans are not displayed on the ND. But constraints are set against the flight plan waypoints and are visible on the F-Plan legs page for all plans and on the ND for the Active plan. You are correct that pseudo-waypoints are predictions, but they aren't the constraint. For the active FP, predictions will indicate whether a constraint is predicted to be met or missed by a magenta or amber asterisk next to the constraint on the legs page in addition to the indication on the ND. Predictions are not available for other plans. $\endgroup$
    – Gerry
    Nov 1, 2017 at 14:58
  • $\begingroup$ @Gerry - OP was asking about the display on ND, I'm a little confused by your comment, for the ND we are both saying the same thing right? $\endgroup$
    – user14897
    Nov 7, 2017 at 9:14
  • $\begingroup$ I was trying to say that your answer was correct, but incomplete. Constraints are applied to actual FP WPTs; e.g. "cross XYZ at or above FL250" or a speed constraint "cross JKL at 250 kts or less". These will display adjacent to the WPT icons on the ND when the CSTR button is pressed. Predictions will color code the constraint based on whether it predicts you will meet the constraint (green) or not (amber). With the altitude example, if you've planned the climb to FL250, the ND will also show the predicted TOC. If it's before XYZ, the constraint will be green. If after, it will be amber. $\endgroup$
    – Gerry
    Nov 7, 2017 at 13:20

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .