Plane spotters may see one on the wing (3)
I believe the answer is:
tab
'wing' is the definition.
(thesaurus)
'plane spotters may see one on the' is the wordplay.
'plane spotters may' becomes 'ab' (I can't justify this - if you can you should give a lot more credence to this answer).
'see one on' says to put letters next to each other.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'ab' after 't' is 'TAB'.
Can you help me to learn more?
(Other definitions for tab that I've seen before include "Flap; meal bill" , "Tally at bar (colloq.)" , "Small flap - bill" , "The bill in a restaurant" , "Till bill" .)