Have recently flown domestically in Europe, and also a leg from the UK to Iceland and return. Seems our initial clearance is always to "destination" via some domestic routing, eg ABC vor UG 99 to DEF vor. However in the USA we are always given "as filed" or "flight plan route" after the initial routing. In Europe this phrase never seems to be included.
So...in the event of no further clearance from atc, are we expected to continue flight plan route?
In the UK at least, the use of 'as filed' or 'flight planned route' is not used since there have been many instances where the plan held by ATC is different from that held by the pilot. So in order to provide a safety backup, a route name or waypoints will be issued ... which may just be the SID. After the SID, which will place you on the route ATC expect you to follow, then you'll follow your flight plan. For overflying or landing traffic in the UK, you'll normally be given waypoints to route to, or a STAR to follow.
The whole idea is to pick up discrepancies so that ATC and flight crews are not caught out by something unexpected happening.
"Flights routing via RATSU shall not call Shanwick for the oceanic clearance. Scottish shall issue a clearance...."
Scottish don't. You have to call Reykjavik Clearance Delivery (CDO) for your clearance prior to entry.