Why didn't planes auto re-base?

[PoorOldSpike]

I say you chaps, got a bit of a puzzler here in this random generated scrap..
That jerry (red circle) has just occupied my airfield, then when his turn ends, my 3 planes (white circles) all crash out of the game because it was their home field.
Why didn't they simply fly to land at my yellow-circled airfield at bottom right? (sniffle)

[Kerensky]

Planes do rebase if their assign airfield is captured.

Only three things prevent this:

Bad weather that pins them to their airfield.
Wrong airfield type, strat bombers can't relocate to dirt airfields.
New airfield is out of range or already at maximum capacity.

Well I guess that's four. So probably one of these four? It's hard to tell just from the screenshot.

[PoorOldSpike]

Planes do rebase if their assign airfield is captured.
Only three things prevent this:
Bad weather that pins them to their airfield.
Wrong airfield type, strat bombers can't relocate to dirt airfields.
New airfield is out of range or already at maximum capacity.
Well I guess that's four. So probably one of these four? It's hard to tell just from the screenshot.

Thanks, I think it was weather that did it, it changed to rain and my planes were caught in it and presumably couldn't see to navigate to a friendly field.