Harley Quinn:
Some replies on here from operators presumably do give me pause for thought wrt to Duty Holder as described by Chris Kebab, Squidlord et al.
FWIW, I am a safety engineer, rather than operator, and one of my clients is the MoD. I am an expert in the technical side of safety but I also have to be involved in the "administrative" side, not surprisingly. So, as well as the technical stuff, I should know where responsibilities for safety sit, and I should understand a term like "Duty Holder".
Do you think it unreasonable that someone should not be responsible for ensuring that an aircraft is airworthy/fit to fly/safe?
One of the (administrative) things that encourages safety is very clear delineation of responsibility for safety. In particular, for acceptance of risk (since any, e.g., aircraft will always operate with a degree of risk to life and limb). Without this clear responsibility, it's much easier for things to slip between the cracks. Things such as unacceptably high risks.
So, I think it is a very good idea that one senior individual should take overall responsibility for the safety of, e.g., an aircraft (which is not to say that lots of other people, e.g. the likes of me, don't also have some responsibility).
That's the sense in which I usually hear the term "Duty Holder" being used.
If it is reasonable for that responsibility to be imposed, where do you think it lies?
Whilst a UK military system is in procurement, I would suggest it is with the relevant PT Leader (or, sometimes, suitably qualified and senior delegated PT member). And that's where the responsibility does seem to sit in practice. Once in-service, for UK military aircraft, the relevant AOA seems appropriate to me but I tend not to work so much on the in-service side so take that with a pinch of salt.