A33Zab,
It then appears paragraph 1.16.6.3 on Page 47 and VS/FPA mode trace on Page 107-108 could be in better agreement ... ?
The AP/FD vertical mode trace is also dearly missing especially in regard to the nature of the selected vertical speed just before the event. What kind of internal conflict was already taking place ... ?
Haven't we heard very recently how spikes could trigger some very wild behavior ?