Supermodel circles capital in aircraft (9)
I believe the answer is:
mosquitos
'supermodel circles' is the definition.
I can't judge whether this definition defines the answer.
'capital in aircraft' is the wordplay.
'capital' becomes 'Quito' (capital of Ecuador).
'in' means one lot of letters goes inside another.
'aircraft' becomes 'moss' (I can't explain this - if you can you should give a lot more credence to this answer).
'quito' placed into 'moss' is 'MOSQUITOS'.
Can you help me to learn more?
(Other definitions for mosquitos that I've seen before include "American natives" , "Bloodsuckers" .)