Originally Posted by
WhiskeyNovember
Thanks so much for finding this. It doesn't seem to specify whether the pylon flaps actually deploy during a control check on the ground. It's possible they only ever deploy while in flight.
In which case, I still question how they can be checked and how it can it be ensured they will function properly when needed.
At the risk of stating the obvious, they aren't very big and from many angles they are hidden by the nacelles.
But you can see them move (just) during the control checks here
https://www.youtube.com/watch?v=aiC2-TRBdqI
at about 3:11.