Original idea losing million before bringing in top aircraft (6)

I believe the answer is:

glider

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'aircraft' is the definition.
(glider is a kind of aircraft)

I don't understand the rest of the clue.

(Other definitions for glider that I've seen before include "Engineless plane" , "Sailplane" , "Flying machine without engine" , "Unpowered plane" , "Plane supported by air" .)

I've seen this clue in The Telegraph.

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