VSF
For nigegilb to suddenly suggest that the training of aircrew contributes to the airworthiness of the machine is changing the goalposts somewhat. I thought we were talking about the airworthiness of inanimate objects here, not the chaps who fly them.
If you are seriously suggesting training is not a component of airworthiness, I suggest you read JSP553 (Military Airworthiness REGULATIONS).
Do a search for “training” and you’ll get multiple hits in each Chapter, and many Annexes. Here’s one, from Ch. 6;
6.14 The IPTL is to ensure that all Aircrew Publications, particularly the AM and FRCs, are available 6 months before the aircraft is due to commence flying in Service to enable timely Service aircrew training.
Evidence given to the various inquests/inquiries indicates this fundamental requirement was breached. The aircraft must be safe to fly (as you rightly say), but it must also be safely flown. Training of aircrew facilitates the latter.
However, as always, I concede various “Stars” in charge of Chinook over the years are on record as totally disagreeing with these regs, including the legal obligation to facilitate and maintain training. I happen to think the regs are correct.