But I didn't see (in calculations) the moment of air load.

Posts 26-28 have the moment calculations...... we used the area of the wing for the distributed load, I already had that calculated for my loading test, and Tdfks had the wing platform dimensions and obtained the areas and distribution that way. We were mostly in agreement on that as regard the numbers so posting of the calculations was not necessary. Going through the details of my loading spread sheet or his spread sheet you would be able to see the distribution.In any case, a 3d element model with an excellent grid of elements is necessary.

FEA is a specialty all in itself, it is great when the output matches the other calculations but I do not have the necessary expertise to use it to any great extent such as my confidence level in the out put approaches that of a simple MY/I calculation. For example looking at my deflection outputs with different runs and only slightly different loading I have outputs of 3" or 7" ....if I hand calculate the deflection based on cuts along the span to get the necessary Moment of Inertia's, I would have a higher level of confidence on my result.