Is a flight plan needed if crossing a border but not landing in the other country?

A while ago I watched a very scenic cockpit video in which a sailplane launched from a French field, made his way to Switzerland by catching lift where possible, then did some ridge soaring in the Swiss Alps before returning to land at his point of origin in France. Interesting to imagine the flight plan he may have filed!

AFIL is sufficient.
And in practice often nothing more then checking with FIS.

E.g. short cutting from Eastern Bavaria to Eastern Saxonia thru Czech airspace.
Or thru Dutch airspace on the western border.
Just ask. Never had a problem.

Practically, I guess if you are going that far an FP is a guarantee to have some search and rescue

On the legal aide, under EASA SERA (= new version of UK ANO) it seems you have to fill FP for any flight appart from those Emir mentioned (circuits and touch and gos), luckily that rule does not define the compliance means so radio/bookings should do, so for a “wide circuit flight” to Calais ILS it will be highly advisable (you are assumed to land there if something wrong happen).

Ibra wrote:

On the legal aide, under EASA SERA (= new version of UK ANO) it seems you have to fill FP for any flight appart from those Emir mentioned (circuits and touch and gos)

Not at all. For one thing, VFR flights in class E/F/G only exceptionally require a flight plan (border crossings being one such exception). Also, a flight plan doesn’t necessarily have to be “filed” in the sense of submitting a complete flight plan form/message into the flight plan system before the flight. When a flight plan is required for short parts of the flight, e.g. to enter or exit a control zone, the necessary details can be given by radio and that constitutes a flight plan. (Note that this is distinct for filing a complete flight plan in the air. That is also permissible, but heavily frowned upon by ATC.)

Airborne_Again wrote:

Not at all. For one thing, VFR flights in class E/F/G only exceptionally require a flight plan

I am bit exaggerating on the scope when a FP is needed but in some places this leaves you with local circuits, but the good thing is one can easily comply if no “physical paper” FP or “central system” FP is required

You could argue that Peter’s scenario fall under SERA.4001.B1-6, especially 3, 4, 5 regrading search & rescue or interception & identification

here local copy

(that document interpretation is CAA UK specific)