If VFR, you have to ask yourself: who checks for a duplicate FP? In IFR, it is IFPS (Eurocontrol). In VFR, I am not aware of any mechanism.
There is no database, other than national-security databases around the place. These could be used to do a duplicate check within a given country.
This sort of thing came up here.
But it seems clear than once a FP has been closed (ARR message) you or anybody else can file a new FP. Whether you are airborne at the time is irrelevant 
But to get back to the topic, other than what ji describes, I don’t see this is a fish worth frying, given the many limitations on this concession (starting with “no CAS”). And if you get it wrong, you could get busted. There have been various busts, IIRC involving border crossings Italy / Switzerland and especially involving some accident. Maybe this one.
Peter wrote
In reality there is no 1hr notice IME.
Some AROs enforce the 60 minute limit. (E.g. the Swedish ARO does,) Of course if you don’t file with an ARO you can file as late as you wish as long as there is time for the FPL to be distributed.
As soon as the departure tower has the flight plan, which will be seconds after it has been injected into the AFTN, you can fly. This is also true for IFR which “in theory” needs 3hrs.
In theory it is 60 minutes, Three hours is not a filing limit but the time when slots are allocated, If you file later you may get a worse slot that you would have otherwise.
Responding would take this even more off topic, so I won’t, otherwise I would need to start a new thread 
More reading can be found with a search.
I am not aware of any new concessions on the earlier-posted rules for not having to file a FP. And we have so many people here from CZ DE CH etc that somebody will post if there is something.
Not so fast. To for instance Sweden from non-EU, it’s not about ATC at all. It’s customs. The Swedish admin obviously distribute to the customs as well. The (customs) rules say one hour before departure. The Norwegian ATC does not forward anything to customs, you have to do it yourself (but you can hook it off if filing from IPPC). The same rule apply though. One our before departure. If flying to a non international airport, it’s 4 hours before crossing the border.
Posted in 2014 here.
