Flight is a very expensive technology, it's use I think would be severely limited if we look at all the factors involved. I have severe doubts about being done sustainably. If environmentalists push this, then I have to feel they have blinders on. But building roads with bulldozers, and trucking out the wood, is an unsustainable use of energy as well, and roads can cause a lot of environmental damage. What it comes down to, from my point of view, is that trees get cut, but nothing close to what is presently done, not even in operations such as yours, even leaving out the part you concede is unsustainable.
People have to know what their lifestyle costs, and cut back accordingly.
I don't doubt that imported pests are a severe problem. I don't know if it is actually the same species, but the beech trees here are being decimated by something that attacks the bark, blisters it up, allows other diseases in. Perhaps 1 or 2 percent of the trees appear to be immune. The hemlocks are also under severe threat by an imported caterpiller. Hasn't reached here yet.