A good book on Blackbird flight test is "Blackbird Rising,"
by Donn Byrnes and the late Ken Hurley. Hurley was an AF
flight test engineer and the book relates his tale of being
in '952 (#3 SR) when an unstart caused a roll past 90 deg.
The pilot got it back down, but while he was doing that,
Hurley was madly writing notes so that there would be some
evidence of what happened in case they didn't survive.

It was a short time later that '952 came apart; there's
a chapter dedicated to it, "Number Three and Jim Zwayer
Died the Same Day."

Byrnes told me that in B-58 testing there were some high-Q
ejections in which crew members' brains were essentially
"homogenized" from the forces, despite the capsule.