Just a personal curiosity to wake up this old thread.

In case of total hyd loss, do flight surfaces lock in place or they will freefloat into wind?

As far as I know, being a FBW (irreversible) flight control system, they are not mass-balanced. In that case, they might be prone to flutter.. just asking, don't know.

Are irreversible desgined if there is no hyd pressure the surface would be locked?

I wonder in case of total hyd loss,

test test test test

Indeed, green system developed a leak which increased during T/O roll. PTU activated, but ECAM is inhibited until 1500ft, which led to Yellow overheat.

Airbus modified the PTU and ECAM logic:
The HYD G(Y) RSVR LO LVL alert is inhibited for the first 15*s of flight phase 5.
The HYD B RSVR LO LVL alert is inhibited for the entire flight phase 5.

So any RSVR LO LVL that can affect PTU operation and thus the other system, will now display much sooner than 1500ft. Suspect around 400ft where ECAM can be initiated.

Just a personal curiosity to wake up this old thread.

In case of total hyd loss, do flight surfaces lock in place or they will freefloat into wind?

As far as I know, being a FBW (irreversible) flight control system, they are not mass-balanced. In that case, they might be prone to flutter.. just asking, don't know.

Are irreversible desgined if there is no hyd pressure the surface would be locked?