Aviator I put into storyline (5)
I believe the answer is:
pilot
'aviator' is the definition.
(I know that aviator can be written as pilot)
'i put into storyline' is the wordplay.
'put into' is an insertion indicator.
'storyline' becomes 'plot' (eg the plot of a film).
'i' inserted within 'plot' is 'PILOT'.
(Other definitions for pilot that I've seen before include "Aircraft captain" , "Test or trial (project or programme)" , "Steer, test (scheme)" , "may be up in the clouds" , "Plane operator" .)