The only one I can comment on is Crimson Skies. However, I have tried to keep the following comments as factual and unbiased as possible. Each player controls one or more pairs of planes, each of which has a separate record sheet used to track ammunition, damage, etc. Pilots are rated in six categories, which modify their various rolls during the game, and can improve these stats through experience if you are playing a campaign game. Planes also have a variety of ratings indicating their maximum acceleration, deceleration, G's they can safely handle on a turn, etc.
Collisions are possible, but good pilots can share a hex without crashing into each other.
Some drill narrow, deep holes in the armor, while others shave off a thin layer of armor over a wide area. Once through the armor, damage affects one internal system after another, perhaps draining a fuel tank, destroying an aileron, or even killing the pilot. Each of these affects the future performance of the affected plane. The planes look as though they came out of a 1920's vision of the future, with pusher props, oddly shaped wings and bizarre fuselage designs. The game world is different and fun, and adds a lot of color to what is essentially a straight combat game.