Airbus has definitely taken the enchantment of “old school” flying from us, everything (almost) has to be done as they state in their manuals.
I agree that if you take a look at the manuals the AC is designed to be flown with the AP most of the time. I guess that's the standard way of Airbus and maybe it has something to do with covering themself in case of an accident/incident.
E.g. In FCOM 4: In case of manual landing:
At DH: Disconnect AP (They don't write about the A/THR)
Can't remember the last time I disconnected at the minimum and landed with the A/THR. (Something I would do with ceiling and visibility close to minima ofcouse. Common sense.)
However, there is no restriction from Airbus regarding manual flight.
And it is possible that your company SOP differ from Airbus SOP. Company SOP has priority, regardless of what is written in the FCOM.
(E.g. Non precision approach:
Airbus: Vapp and landing config when intercepting final descent
My comp: Flaps 2 and 180kts at final descent
Big difference, but I prefer the second
)
My point is that the FCOM is not the holy bible
