No, actually, I think I was partly wrong. I have just re-read
DSC-27-10-20 "Roll control" which states, (from Airbus FCOM):
ELECTRIC CONTROL
- The ELAC 1 normally controls the ailerons.
If ELAC1 fails, the system automatically transfers aileron control to ELAC2.
If both ELACs fail, the ailerons revert to the damping mode.
- ..........
Normally on a schematic or an electrical diagram, if two separate components in different parts of the diagram operate together, there would be a dashed line drawn between the two components to indicate this. But they probably left those out to de-clutter the diag.
Also, while I am in the FCOM:
AILERONS
Each aileron has two electrically controlled hydraulic servojacks.
One of these servojacks per aileron operates at a time.
Each servojack has two control modes :
The system automatically selects damping mode, if both ELACs fail or in the event of blue and green hydraulic low pressure.
Active :Jack position is controlled electrically
Damping :Jack follows surface movement.
The bottom line though is that us pilots don't need to know the exact ins and outs really; the system has multiple redundancy layers. In the event of a failure the ECAM page and STATUS page will tell us what is what and what we need to do.
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