I think the principles are the same in the US and in Europe. A successful flight test is P1(s).
Doing the FAA IR checkride, you're in the strange situation of being P1, under the hood (so can't see out). The examiner is Pax but looks out to ensure you don't bang into anything.
But you can't fly in cloud while under that hood, because then you would be IFR and don't have an IR yet and the examiner is only a passenger...
Not sure how you'd know you were in IMC, mind
