Resolve shown by one working aboard flight (4,3)
I believe the answer is:
iron out
'resolve' is the definition.
(I've seen this before)
'one working aboard flight' is the wordplay.
'one' becomes 'I' (Roman numeral).
'working' becomes 'on' (on can mean working or activated).
'aboard' means one lot of letters goes inside another.
'flight' becomes 'rout' (I have seen 'Headlong flight ' mean 'rout' so perhaps 'flight' could also mean 'rout').
'on' going inside 'rout' is 'ronout'.
'i'+'ronout'='IRON OUT'
'shown by' acts as a link.
(Other definitions for iron out that I've seen before include "Smooth, clear up" , "Settle (problems)" , "One might ask caddie to get this" , "Get sorted" , "Solve (one's differences?)" .)