I am just on my first run through with the game and I had a situation where the German army was going through Belgium and an Allied aircraft unit was caught in the front line. It was badly damaged in one turn, but then instead of flying off somewhere for repairs, it stayed put, got reinforced, and then was completely destroyed on the next turn. There were French army units behind it that could have engaged the enemy instead. It did seem a bit odd to me, notwithstanding some of the suggestions here that are saying that their would be other troops with the planes. I would prefer it if aircraft always flew off to a safer area.
Just catching up on some of these earlier posts that caught my eye, and the reason for this particular AI behavior is that once Belgium falls the Belgian air unit would be removed from the map. In this case, and purely from a game play point of view, it arguably makes more sense for the Belgian air unit to stay put and hopefully cause some counter damage in any future attacks upon it and/or to slow down any further advances. A human player would likely do the same thing in this case and the AI is simply mimicking the optimal game play behavior here.
The reinforcement is I agree questionable, and something I can look into if its job is to stand and die, but in other parts of the map where air units can and should logically retreat, they should be doing so.
