I have made a step backward and reinstalled the steam original version of the game the one without the 1.07 patch and no crashes anymore, not one! I have tried most of the test I did with the 1.07 patch and no crash of the game at all. So I must conclude it is not my PC but the patch how is faulty! Sorry.
Now I am reinstalling the 1.07 patch because the Spitfire MKIa oct and all 100 octane RAF planes are more fun to fly.