Thud,
In case you have not heard of this bit of Aerobatics (uncommanded) by a US Army Chinook Crew....it is compelling reading.
I am trying to find data that will connect this event aircraft to the one seen self destructing in the "Ground Resonance" video over in "Rotorheads" forum.
A reference Iinked in that thread mentions the aircraft in the video was "the one that went inverted" earlier in its life.
http://www.chinook-helicopter.com/Fl...x_May_1998.pdf