...may well have never been even remotely aware of the consequences of using the powered rudder aggresively at higher speeds.
They positively know NOW.
Was the concerned pilot in error?
Most certainly.
But, even more importantly, so was the concerned aircarrier, American Airlines (aka, the Sky Gods) for developing an advanced maneuvering program involving abrubt full rudder movements at high(er) speeds, and the FAA inspectors for approving it.
Abrupt full rudder movements repeated at high speeds are absolutely to be avoided, least you want to have an even longer career flying heavy jet transports.
The older guys were taught...now clearly, the younger guys now know, especially at AA.
