Are the French military zones around Cazaux ever flyable below FL200? (and Eurocontrol routings through temporary restrictions)

Peter wrote:

One part-solution, done by the routing tool, would be a checkbox option to route only inside CAS.

A more or less equivalent is called “discourage DCTs” in autorouter. I use it every time for this particular reason. It works well.

Peter wrote:

On IFR flights, you get enroute notams, and go through the booklet which comes with the SIA 1:1M charts which lists the various D R and P zones and their activity times,

Discouraging DCT = flying airways.
Most airways (below FL195) in France are PDR (permanent, and not CDR).
By design, PDR airways avoid P, D, R areas, so there is no need to check the SIA 1:1M and the booklet.
So I can discard every NOTAMS regarding P, D, R area activation time.
I just check the en-route notams to see if there is no TRA created for a special events.
“Big war” exercises creating TRA’s (and airways non-availability) such as this one local copy (simulating a nuclear raid…) are rare (once or twice a year) and usually occur in the middle of the night.

But if I file a DCT in my FPL (like you did), I look carefully where it gets me including P, D, R areas activation times.

I get longer routes on autorouter but when I’m the air, I let ATC do the work : they will give you a shortcut when a restricted area is not active.

I’ve never encountered any problem flying that coast much lower tan FL200 . This was on monday a few months ago.
A few moths ago, I went up all the coast from Biarritz to Oleron between 1000-2000’ AGL

Flew straight through last Thursday, FL80

Morning and early afternoon

Great pic, coolhand. View of the dune was not as nice from up there