Boxer/ atomic, thanks for your replies.
1/ Concerning FCU, your explanations have really enlightened me. Only two positions : managed or selected. It means that as soon as an autopilot is active (AP switches on FCU), all guidance mode becomes active, (Speed, Heading/Track,, Alt, Vertical spd/flight path angle) in either managed or selected mode. Therefore, I can't engage only speed or altitude, without having other modes active ?
2/ For Vls = 1.23 Vs as a Vref for full flap landing, ok.
Atomic, you said " Vls as it shows up on the PFD airspeed tape. This constantly varies according to
the current configuration and flight condition. "
Does " flight condition " used to compute this Vls include the load factor ?
I mean : will Vls value change between a 1G flight and a 1.3G flight.
3/ No problems.
4/ I saw that with APPR switch armed above 8200' AGL, glide slope capture was disengaged because of the loss of Radio Alt signals above this altitude. I would like to know if others constraints exists concerning LOC and GS capture, especially considering relative runway / airplane positions.