SLXOwft
Thanks for your really helpful post. I note that the Key.Aero link is only for subscribers but the information you have provided shows that, not for the first time, a very small detail on a large airframe can be catastrophic for the crew.
I didn't do any of my own digging first as I know that there is a wealth of knowledge and experience on the forum and some may be stuck indoors on another grey and rainy day in the middle of the British summer!
Thanks