Lyman
Your quote:
Does the GP have an IPT turbine that is affixed with the same architecture as the T9?
The GP7200 engine does not have an IPT rotor, it is a two spool engine and the HPT consists of two rotors, Stage 1 and Stage 2.
Your quote:
I do not see the LPT vanes at all in the GE/PRATT.
Perhaps this view of the GP7200 will enable you to see the Stage 1 LPT nozzle in relationship to the Stage 2 HPT rotor.
Your quote:
Because any aft movement at all of the IPT in the TRENT puts the aerofoil ring into the LPT Stator. Isn't that accomplishing the same thing as the GE in wheel loss?
I don't think it does on the Trent because of the angular lean of the Stage 1 LPT vane, refer back to the Trent cross section. The impingement between the two on the Trent is close to the blade root and disc pine tree holding the blades and the inner band extension of the Stage 1 LPT nozzle ring. If you look at the recovered parts photographed in the ATSB report, you can note 2 items of interest. On the recovered LPT vane segment, the inner band is gone. Also, the turbine blade retainers on the recovered portion of the IPT disc are all missing. So you have relatively one smooth surface contacting another relatively smooth surface. Beyond, these observations, nothing more can be said with any certainty. Even with all the recovered parts, lab analysis, etc., plus the assistance of the engine designer and builder, it is difficult to reconstruct the minuscule details of exactly what happened in the few seconds following the release of the IPT rotor disc and blades to the degree you are attempting to without the complete data the ATSB possesses and the knowledge RR has on this engine.