Chief pilot is an idiot (7)
I believe the answer is:
airhead
'idiot' is the definition.
(I've seen this before)
'chief pilot is an' is the wordplay.
I cannot really understand how this works, but
'chief' could be 'head' (synonyms) and 'head' is found in the answer.
'an' could be 'i' (Roman numeral for one) and 'i' is found within the answer.
The remaining letters 'ar' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for airhead that I've seen before include "Simple-minded soul" , "One not very bright" , "Silly" , "Vacuous person" , "Scatterbrain" .)