Originally Posted by
Roffa
IO540,
Please elaborate further...
Is that the out of step part or the can't change part?
With regard to the out of step.
In France, Ireland, Oceanic (and the US), even if your flight plan takes you out of controlled airspace, you don't loose your clearance back in again, the controllers appear to co-ordinate this just like they co-ordinate moving from sector to sector.
It is only the UK where you can embark on an IFR flight and part way through discover your planned and acknowledge route is no longer available and you now have to make it up on the fly. I accept that a UK pilot should 'know' this is going to happen if he files an OCAS DCT or for a level below the UK airway base. However, this has never happened to me in any other country even if I have requested a level below the airway base (but above their MVA).
In the US this dipping out of CAS is really only an issue on approaches (where it would be pretty silly to not protect the missed approach just because the aircraft has descended below 1200/700 AGL) or the middle of nowhere (where it doesn't actually matter). However, the French and Irish (and I think the rest of the Europeans that allow IFR in class G and have Class G) all seem to maintain the clearance end to end.