Airlines flying over the capital of an island (5,6)
I believe the answer is:
saint helier
'capital of an island' is the definition.
'saint helier' can be an answer for 'island' (I've seen this before). I'm not certain of the 'capital of an' bit.
'airlines flying over the' is the wordplay.
'flying' indicates an anagram.
'over' is an insertion indicator.
'airlines' anagrammed gives 'sainlier'.
'sainlier' going around 'the' is 'SAINT HELIER'.
Can you help me to learn more?
(Other definitions for saint helier that I've seen before include "Town in Jersey" , "island town" , "Capital of Jersey" , "capital of island" .)