Camlobe
If you have any engines on extension that have AD’s applicable at overhaul, you had better inform the owners that they are possibly flying without a valid CofA !!!!!
See GR24 para 3.1.1 for items that must be complied with, in particular (b)
“Compliance being shown with any applicable Airworthiness Directive which
requires compliance at engine overhaul, unless otherwise agreed by CAA.”
I have never been able to get CAA agreement to extend any of the applicable AD’s.
ACX