There are two methods of joining the circuit at an uncontrolled French airfield. As noted above, both start at 500 feet above the circuit height, i.e., normally at 1,500 feet AAL.
The first method involves turning overhead the active runway onto the runway QDM and descending to circuit height well beyond the normal position for the crosswind leg.
The second method is to fly over the airfield and fly for one minute beyond the position of the downwind leg to make a descending turn back to join the start of the downwind leg (on roughly a 45 degree angle).
Capt Sparky