"Peter" wrote in message
...

What I meant was can
one say depart VFR (no flight plan) and upon seeing cloud ahead call
up and ask for an IFR clearance. One needs to have an IR of course.
How easy is this sort of thing to do in reality?


Yes, one can get a pop-up IFR clearance. How easy it is depends on how busy
the controller is.



Here in the UK, we can do it (in Class G) without any radio contact,
which I believe is unique in Europe.


That can be done in the US where there's enough Class G airspace.