Using the example above, what FPL is filed? EKCH, EGLL or one of each with a A appended to the ident?
We had a similar problem today where permits required us to remain filed to somewhere we knew we weren't going, but we wondered how to tell actual destination ATC we were coming other that just through the handler. Other bloke on shift reckoned we should file another FPL with a A on end that crew switch to with ATC, but this seems clumsy ...and probably inadvisable!