I now have another qustion for the Chaps landing a 320 manually.
How? Diff thrust? Or does "manual" mean that some hydraulic power remains? Manual reversion is not possible on the 320 I thought.
@Turin
The correct term is MECHANICAL BACKUP (not manual backup, I'm sorry).
It is only for temporarily use, if all 5 flight control computers gave up and a reset is necessary. With MB the aircraft is controlled via pitch trim (manual) and rudder (cable). Both need hyd pressure. MB is not designed for landing, but it has been demonstrated that it can be done.