Originally Posted by
Reely340
So if I got that right it's exactly the opposite of the EASA E-IR:
IMCr: enroute OCAS IMC VFR, controlled IMC app/dep
E-IR: enroute CAS IMC IFR, uncontrolled VMC VFR app/dep
or did I mess up?
Pretty much.
IMCr: enroute can be VFR or IFR but must be outside Class A, B, C airspace. Can be enroute in Class D (so via airports) but not in airways or TMAs (which tend to be Class A). When outside controlled airspace, you don't have to talk to anyone, although in most of the UK radar services are available from military, airports and area controllers (when high enough) although it generally isn't a joined up service when in quiet areas.
As Gertrude says - you can just decide you want to be IFR when outside controlled airspace, and then you are. You don't have to file a flight plan.