Pitch Upsets at low level.
Sound Barrier:
I was a member of the crew in a Falcon 20F many years ago at Sydney airport that had this problem. It certainly got our attention. I will post the link to the article.
To start to answer your question, our nose went to about 70 / 80 degrees with full forward control column and I rolled the aircraft to the left but could not get the nose down until we closed the throttles. We did a series of these recoveries.
Regards
Tmb