Flying Officer reporting to an architect (7)
I believe the answer is:
founder
'architect' is the definition.
(both can mean a pioneer or initiator)
'flying officer reporting to' is the wordplay.
'flying officer' becomes 'fo' (this could be a standard abbreviation which I don't know about).
'reporting to' becomes 'under' (I've seen this in another clue).
'fo'+'under'='FOUNDER'
'an' acts as a link.
Can you help me to learn more?
(Other definitions for founder that I've seen before include "collapse" , "One who establishes an institution" , "Institution's former" , "(Of ship) fill with water and sink" , "One sets up firm" .)