AF 447 Thread No. 7

[roulishollandais]

Is still anybody here ???

@A33Zab
Please, Do You have the answer to Grity's question (AF447 THREAD 7 post #730)

"what did you think is the frequency for the natural roll stability for a330 at this high and speed? "

In my own experience the frequency of the resonance was around 0.4 hz

@MachinBird
The Dutch roll is of much interest : equations have the lowest degree ! That means too that no additional energy is put in the closed loop (very very important).
For any other oscillations, you need to enlower this degree ! Otherwise you have not only inflexion points but inversion points in the response, and that cannot be managed by the pilot in flight.