Successful Tactics In Air Combat

UFOs select one target and stick to it. I always have several aircrafts even when attacking one UFO (except for later stages when I have big edge). At the beginning of the combat I order aircrafts to go in different directions, and by the way UFO reorients itself I can see which one did it select as the target. From that point on the "target" just flies away, while the other plane(s) could easily go around the damage zone and attack the UFO from behind.

Front attacks could work with evasive rolls if you are only been targeted by a rocket like weapons. Note that you can even fly away from the "rocket" when it approaches you from a side. But these are more risky maneuvers.

Auto-resolve sometimes shows unrealistic results. For example, it could show a 95% chance to win when the total damage your aircrafts could do with all the weapons is lower than the amount of hit points the UFO has. It seems that the aircraft damage does not vary that much, so sometimes I use auto-resolve to "cheat" if I am too lazy to do 95% damage to the UFO, return to the base reload and then attack it again.