Just going back to the point about CAA oversight of Ryanair's operations, the CAA has the right to request of the IAA powers to oversee Ryanair's operations under Article 83(bis) of the Chicago Convention.
This provides for an airworthiness authority to delegate oversight of an operation registered in its country to the airworthiness authority of another country. In short, it provides for situations such as that where the majority of Ryanair's operations fall in the UK instead of its state of registry, Ireland.
I wonder if the UK CAA has ever endeavoured to request such power to be delegated to it by the IAA under this article?