ptkay
Almost every second flight of these aircraft 101 and 102 was plagued
recently by different technical issues.
Hopefully you know that there is no MEL on Polish Air Force TU154M, unlike LOT 737. It is not designed to be commercially effective, and it is not dispatchable with carry-on defects. If you don't see the difference, I guess we have nothing to discuss.
When it comes to investigation, don't forget that this is not a civil aircraft and not a civil flight. None of usual arrangements you have in mind are applicable.