Following a discussion on Facebook, it's been noted that SD doesn't identify that a Flight Plan is required from, say, Jersey to Cherbourg.

Hello,

I feel, finding a suitable algorihm for requirements of a FP is really (too?) complex and the risk is, the more sophisticated the algorithm is, the more the people take the "recommendation for granted"
Example: Flights from Germany to Austria normally does not require a flightplan (SD recommends one), but when landing in an controlled airspace in Austria, you will need one. So, already two rules for only from Germany to Austria, from Austria to Germany is different again. And I can imagine lots of complex rules in other cases.
So iI think, giving a recommendation according to FIR-comparison suits ok as a quick and simple recommendation. Buts of course in this case, maybe one recommendation too much (positive fail) is better than one to less

Best regards
Ralf

Hi again,

I just played around a little bit. I think, the point is, that the existing algorithm fails, when the FIRs (controlled from different countries) are not exactly aligned to the real county borders. This is the case e.g. for EDGG and LSAS
Example: EDTS (Schwenningen) and EDTZ (Konstanz) are both in Germany, but EDTS is FIR EDGG and EDTZ is FIR LSAS, consequently SD recommends a flightplan (but to be honest, EDTZ is THE ONLY german airfield in LSAS, therefore an absolute exception)
But obviously, with the Channel islands and Cherbourg, the same situation applies (and there are maybe more elsewhere in the world)

Maybe an improvement could be, taking this situation into account and check also the real country borders (I do not know, wether this is possible or not with the existing data)

But this enhancement would not cover the specialities as stated in my previous post.

br from EDTS
Ralf