Doc, Doc, Doc...
I am compiling all this stiff right now...
The Boeing test did not have a person on the stairs or jumping.. they only lowered the stairs. They wouldn't have open very far with no weight on them, no pitch, bump, oscillations.
This can't be compared to a jumper.. their weight pushing stairs down and releasing.
Rataczak was told to expect a pitch and there was..
The 8:09 little bob on the FDR was Cooper getting to the bottom of the stairs, maximizing drag with his weight opening the stairs.. the stairs were opened earlier but not opened as far with much less drag and no pitch.
Pitch was caused by Cooper at the bottom of stairs not when stairs cracked open earlier.
The FDR mark indicates Cooper was at the bottom at 8:09, no later marks. If this mark was not Cooper maximizing drag then what was it and wouldn't there be another mark later.
The only question is how long was he at the bottom of stairs from 8:09 before jumping.... causing the physical bump.
expect a slight pitch..