Vecvec, I used to not think about it just like you. As tuc says, I didn't really need to, it was a given in my day. Difference is you do need to now, because it isn't.
Fat Chris. My credibility? What credibility? I'm a BOF for God's sake, we don't have any! What you need to ask yourself is how much credibility is there in the MOD as the UK Military Airworthiness Authority? Before answering make sure that you have read the Parliamentary Questions thread re Hercules, the Nimrod XV230 thread, and the Mull sticky above. No time? I should try to make time if you haven't already done so. Oh, as regard "factors" they are all potentially pertinent. That's how Accident Investigation is supposed to work!