• Dear ipacs, I am doing many flights on the Airbus 321... flights in Europe, reaching 8 thousand feet, I get an alert in the ECAM called ALT CST*, what does it mean? Are there new implementations or alerts?

    The altitude constraint... is, as explained... an altitude constraint. On a SID or STAR... you cannot surpass the altitude... unless OP CLB is selected.

    Kind regards and safe flying.


  • The ECAM does not have any ALT CST* alerts... You probably mean the PFD and the upper most part of the PFD is called the autopilot flight mode annunciator, FMA. In the FMA you can see what the autopilot modes are and ALT CST* and ALT CST are the altitude constraint capture and hold modes. These are two modes that engage when the SID or STAR define a required altitude limit.

    If you select CST on the navigation display then you can see where this constraint ends.