Originally Posted by
Goldenrivett
This
picture from DSC-27-20-10 Normal Law shows that Lateral Control control is still in Normal Law until touchdown (then blends into Ground Mode over 0.5 sec). Most PIO I've witnessed below 100 feet was in Roll because of continued roll input whilst applying back pressure during the flare. Roll control must still be "nudged" rather than held.
Whilst on the ground, I suggest you ask your student to show that that they can hold a bit of constant back pressure whilst they "nudge" a roll input left then right. If they can't - then get them to change their arm rest position until they can.
Another thing to teach the trainees that will help them is that, to make a pitch input, the sidestick has to be handled slightly to left hand side (for an FO sitting on the RHS). The ergonomy of the side stick dictates it to be slightly tilted to the left hand side to accomodate to the natural position of the right hand when it is resting. On ground, and with the engines running, ask them to make a pitch-only input on the side stick, and observe the cross on the PFD, Vast majority of them will pull or push the side stick following a perfect vertical motion, making the cross go up (or down), while turning slightly to the right. Let them find their own way with the side stick until they are able to make a pure pitch input, so when they flare they don't inadvertently command a roll as well.
Sounds complicated (even more so when English is not my mother tongue), but once they see it they understand what it is all about.
And, about arm rest position, they should be able to make a round circle on the side stick without having to move or elevate the wrist, to avoid having some positions of the side stick in which they'll be using the full weight of their arm, which may cause them to overcontrol. As for the legs, same old thing: full pressure on either pedal should be achieved with the leg slightly bent, not perfectly straight, to make sure they can hold the pressure without shaking during an engine failure.
About the height, I teach them to find the height where the top frame of the PFD touches the bottom side of the FCU panel, and do to it with the seat in an upright position. Much easier for them to get their visual references right for landing.
No trainee of mine has crashed so far during landing, so I guess these tips helped them...