Where pilots go to be confirmed (2,2,3,3)

I believe the answer is:

up in the air

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'confirmed' is the definition.
Both the answer and definition are adjectives. Perhaps there's a link between them I don't understand?

I don't understand the remainder of the clue.

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(Other definitions for up in the air that I've seen before include "skylarks singing here?" , "9 [FLYING]" , "Where hang-glider may be spotted" , "position of hawk or dove?" , "Where are the clouds" .)

I've seen this clue in The Independent.

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