Originally posted by grity ...
.... or is it a typical self-induced pitching movement of an A330 with higher AoA?
Hello grity,
They were the test pilots taking an A330 into its first stall, and the period you have referred to is what I have called the 'PRE STALL'. I believe that pitching oscillation occurs as the wing starts to lose lift and the nose drops, then momentarily recovers lift and the nose pitches up. The fact that the elevator and THS were max NU may also have had a bearing on this oscillation.
IMO the pre stall buffet the BEA tried to define is not very clear, but the pitching oscillation in hindsight appears to be the very last clue.