Scheme to involve one expert at banking? (5)
I believe the answer is:
pilot
'expert at banking?' is the definition.
(banking is a type of flying manoeuvre)
'scheme to involve one' is the wordplay.
'scheme' becomes 'plot' (plot is a kind of scheme).
'to involve' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'plot' placed around 'i' is 'PILOT'.
(Other definitions for pilot that I've seen before include "Plane flyer" , "Person in charge of aircraft" , "air traffic controller?" , "trial episode" , "Navigate" .)