[caldrail]

The problem is that the default runways are linear features, so for safety a pilot wouldn't ordinarily land unless the runway is clear. The game relies heavily on radio traffic control which wasn't widely used for aircraft movements in WW2. Usually pilots made a visual decision and went around if someone fired a red flare, but then, unless you were flying heavy bombers from a concrete runway the chances were you were operating out of a grass field, which gives you plenty more choices - you always land to the right of the aircraft ahead (if I remember right, it might be the other way)

Now that wider grass fields are appearing on maps, one answer is to lay a series of parallel runways on the field allowing the AI to land on all of them simultaneously, but the risk of collision is much greater and the AI can't see with his raybans on.