Originally Posted by FDMII
Nor is there anything informal regarding the transition [to Alternate Law-Roll Direct] Those who have trained-on / flown the Airbus do not seem to find the transition (from Normal to Alternate I/II / Direct) problematic, nor are two samples in millions of flights, statistically significant.
First let me make clear that Alternate Law-Roll Direct is a specific type of Alternate Law where pitch is a C* law with reduced or no protections and roll is a direct law where aileron deflection is proportional to stick deflection.
As long as one knows he is dealing with Alternate Law and approaches with careful control inputs, I have no doubt that control is like any other aircraft.
Now take that same alternate law aircraft and start with near full deflection roll inputs in cruise and tell me what happens. That is what happened with AF447 and QZ8501. In both cases, it not clear that either PF knew from the
outset he was in Alternate Law. That is a setup for roll PIO. Do you understand the hazard that roll PIO presents?