Originally Posted by
avieh7
will appreciate if one of you, A320 experienced Drivers, will tell me what’s happening when during an ILS (LOG, G/S engaged, and Alt is set to go around altitude) the Alt knob is being pushed..? (in terms of modes changes) and how to revert back to ILS...
Nice one.
Above 400 ft RA :
DISENGAGEMENT CONDITIONS OF G/S ONLY
‐ The flight crew pulls out the V/S or FPA knob. LOC mode remains engaged, but G/S mode
disengages and V/S or FPA engages.
‐
The flight crew pushes or pulls the ALT knob.
LOC mode remains engaged, and the mode selected by the flight crew engages, as a function of the FCU selected altitude.
BUT :
The descent mode is a managed mode that may be engaged during cruise. It can be armed or
engaged in descent and approach phases
(except if the FCU selected altitude is higher than the
present aircraft altitude).
Throughout the years I have had a few trainees caught out of startle effect pulling the ALT knob when setting the (higher) GA altitude ending up in a cancelled approach (no big drama, lesson learnt I guess). Regarding the "pushing" I am not sure, as the aircraft is on the correct vertical profile (vertical deviation centred) but the GA altitude is (let's say) above Your current altitude so technically nothing should happen but let's see if someone has experienced it and can shed some light. I will be in the SIM in a few days anyway so will try it out (still not close enough to retirement to try it on the line).