A flier manoeuvring round ring twice showing source of lift? (8)

I believe the answer is:
aerofoil
'source of lift?' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'a flier manoeuvring round ring twice' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
'round' could be 'o' (o is a circular letter) and 'o' is present in the answer.
'ring' could be 'o' (letter resembling a ring) and 'o' is found within the answer.
an anagram of 'flier' is 'erfil' which is located in the left over letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'showing' acts as a link.
Can you help me to learn more?
(Other definitions for aerofoil that I've seen before include "Part of aircraft designed to give lift" , "Lifting section" , "that may improve grip" , "Part of aircraft giving lift" , "Curved lifting surface" .)
