It may come before and after landing (6)
I believe the answer is:
flight
This might be a double definition.
'it may come before' is the first definition.
The definition suggests a singular noun which matches the answer.
'after landing' is the second definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'and' acts as a link.
Can you help me to learn more?
(Other definitions for flight that I've seen before include "Journey made by plane" , "Series of steps" , "Tail of an arrow or dart" , "Air force unit; running away" , "Set of stairs" .)