The regs might say 500 ft but who in the military in france obeys that!
Many moons ago I did a microlight license at an airfield notified to the dgac...had an airmiss with a pair of mirages ...one of which we heard...the other who knows.
My brother was instructing a customer with a small basic model aircraft trainer...two pairs of super etandards flew over the field ..one pair below the model. Again the airfield registered with the dgac.
They have taken out a few microlights over the years.
I should add that they use the area for basic cross country training...rather foolish to plan over airfields imho.
On a similar subject of low flying military watched a Tornado cross the Thames from the london eye south to north ...way below the 500ft rule.