In all three editions of AD&D there is a reliance of flying maneuverability classes to govern flying. From a game designer perspective this seems reasonable. Some creatures are more maneuverable flyers than others. However, the worst flyers are horribly bad at flying. For example, in AD&D a dragon can only turn 30° per round. That is 30° per minute. That means it takes a dragon after making one pass at a point 12 minutes to return to that point on the wing. Third edition appears to use similar rules with more paperwork involved, I haven't used them thoug. The problem is mitigated by a shorter round time, but dragons are still lousy flyers.
Let's take the dragon as our example in think in terms of Gygaxian naturalism for a minute. Here we have the ultimate predator. Intelligent, winged, breath weapons, claws and fangs. They are enormous and are going to need to hunt large quantities of prey. However, since they are too clumsy in the air to hunt on the wing like a raptor, they are going to have to do one of two things: blast everything with their breath weapon and then scavenge whatever remains; or fly somewhere, land, hunt on foot. The latter makes no sense really - whatever are the wings for then? The former is sensible but makes dragons kind of sad. Dragon attacks will involve a quick blast of death from above and then everyone hiding while it makes its turn, and then staying hidden while the dragon roots around in the ashes. Sucks to be a dragon, they are going to need to resort to stealth. I do see an opportunity for dragons ambushing and sneak attacking shepherds, adventurers, and other unfortunates, but that would be a complete reimagining of the dragon as the iconic enemy.
These rules appear to have been by people who have never seen raptors hunt. On my way to work I pass through a wide stretch of flood plain where I sometimes see hawks hunting. They really don't seem to have any trouble with these rapid banking maneuvers and dives that are deemed impossible. For what its worth, I am no ornithologist, nor even a serious bird watcher. I just have seen birds around, you know? I think the authors (of 1st, 2nd, and 3rd editions) have confused raptors and airplanes. Birds are good at flying. Shouldn't flying monsters be good at flying? If we take Gygaxian naturalism seriously at all, flying predatory monsters should fly like predatory birds. Why does being big mean they have to be clumsy? A dragon probably should have hollow bones and the wings will be governed by enormously powerful muscles. They should fly like an eagle. Wyvern's should fly like hawks.
I think a little imagination can replace all of the flight rules completely. Watch some Wild America (is that still on?) or something. Think about what kind of flyer this creature is. Rule appropriately.
Note: Pathfinder eliminates this sort of absolute thinking and replaces it (like everything else) with a skill check. Not a bad idea, since it encourages flexibility, but it has all of the difficulties that all Pathfinder skill checks have. Endless tallying of modifiers.