Oh boy, my Russian friend, you have made me so glad, by announcing a WWI flight sim !!!
I've taken a brief look at your forum, and here are some (hopefully helpful) comments:
The graphics look promising! I don't have to say this, of course (but I will

): pay attention to the DIFFERENT sounds of the engines of the different planes, a lot of research is very necessary!
- realistic atmosphere above all ! This is very important, certainly for WW1 sims, because they have a certain public, and they want to feel, as if they're back in 1914-1918, and some beautiful planes and tanks are not enough to create this 'atmosphere' !
- I've seen that you are paying a lot of attention to research and realism, keep going on like that!
One remark: I understand that it is a lot of work to cover every plane with their specific 'behavior' , but still, I find 13 planes a little too few. More planes would be welcome! And CERTAINLY include the gunner's function in a bomber!
SUCCES !!! and keep us updated ! I'll certainly buy your game, that's for sure !