One way to think about the difference is that a managed mode has a navigational feedback mechanism to ensure that the aircraft is following a navigational path to a particular target.
Whereas the only feedback mechanism with a selected mode is to ensure that the selected value is followed. The pilot sets a speed, V/S, FPA, HDG etc and the aircraft will follow, but does not use navigational feedback to adjust the values to achieve a navigational target - only the pilot can change them.
So a managed NPA will follow a navigational path, but HDG/FPA will only follow the values set on the FCU. These values might be incorrect, and without manual intervention you could end up in the wrong place.
For this reason, I would class an ILS as a managed mode, because it uses navigational feedback to adjust and guide the aircraft along a tightly defined path.
Magenta = Managed.
Cyan = Selected.
The ILS LOC and G/S scales are in Magenta, so this suggests to me that Airbus consider it to be a managed mode?
PS, NAV ACCY has no bearing on a conventional ILS because the guidance follows two specific navigational 'beams' physically transmitted from the runway in question, it is not navigating the ILS by reference to IRS or GPS etc.
.
Last edited by Uplinker; 24th Jan 2017 at 09:14.