Turbine D
I think the problem with the simple solution (Occam's razor) has to do with what lomapaseo pointed out. When there isn't much forward speed, but significant vertical drop speed, inlet distortion comes into play on commercial high by-pass fan engines. The engines become starved of air, stall and flameout during the rapid descent resulting in the spool down situation. Whatever rotational speed is left, it ends at impact. Quite honestly, the vertical speed in this incident, resulted in one of the most significant destruction of a high by-pass engine I have ever seen. Even the TWA 800 engine appeared to suffer less destruction.
The TWA800 engines and PA103, and etc. etc. all hit the ground/water in free fall terminal velocity relatively flat, shearing the LPT turbine case and last stage turbines away from the rest of the engine. However, that while their fan cases were also sheared away the fan rotosr stayed with the engines and thus the blades were easily visible for examination.
The only thing that seems to be different here is the completely missing (to us) fan disk and blades. No doubt there are lots of other photos that the investigators have to work with so I'm not going to try guessing at their hand
