Aircrafts withdraw from battle remaining in the territories where the battle is fought, in this case Norway.
In the non combat move they have to land in the same way you do if you had won the battle. So they may come back to England, land on AC or in any other legal space they can reach.
New units
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Where to buy new kind of units? I want also a description of the unit like attack defense andfeatures
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Check this site: http://www.historicalboardgaming.com
There are no rules for those extra units. You have to make them yourself. But then you can better go to the forum for house rules.