Prison warden blowing his top – nothing new in section of wing (7)
I believe the answer is:
aileron
'section of wing' is the definition.
(I know that aileron is part of the wing)
'prison warden blowing his top nothing new' is the wordplay.
'prison warden' becomes 'ailer' (I can't justify this - if you can you should give a lot more credence to this answer).
'blowing his top' means to remove the first letter.
'nothing' becomes 'no' (similar in meaning).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'no' with its initial letter taken away is 'o'.
'ailer'+'o'+'n'='AILERON'
'in' is the link.
Can you help me to learn more?
(Other definitions for aileron that I've seen before include "Aeroplane's wing flap" , "Aircraft control flap" , "Hinged part of a plane's wing" , "Hinged flap on aircraft wing" , "An oriel, strangely, on an aircraft" .)