@ #11
The ailerons and elevator flight control surfaces have two servo jacks each.
Normally, one jack is active - moving the surface, the other jack is passive - in damping mode.
Damping does
not restrict the
travel of the surface or the other jack; it just damps it - stops vibration or flutter.
Have another read through of the chapter starting with DSC 27-10-10, in particular the General Architecture diagram at DSC 27-10-20. The diagram shows which surface is controlled by which Hyd system and which FBW computer. The arrows next to each surface show the sequence in which the computers take over from each other if the primary computer or Hyd system for that surface fails.
Take your time and read the whole chapter through several times slowly, with a cup of tea or something. It looks complicated but the principle is quite simple
