Interesting conundrum, and it prompts me to repeat a question recently posed regarding our company SOP.
On passing the local minimum safe altitude, in response to the challenge "Passing MSA" the required reaction is to confirm "Position checked" (climbing and descending), and (in the descent) state "Radar control"/"Procedural"/"Visual".
Now then, I guess "Visual" is obvious, "Procedural" means following a published, pilot-interpreted profile (or procedure), and "Radar control" is also obvious if the aircraft is in controlled airspace ... but at many regional UK airports the arrival is flown in uncontrolled airspace, so, the question:
Is it possible to be in receipt of a radar 'control' service - positively identified by an appropriate radar unit/controller, under IFR and accepting their instructions - even when outside controlled airspace?
If not, then what would be an appropriate resposne to the challenge "Passing MSA" to confirm the flight status?