Make emergency landing in Channel (5)
I believe the answer is:
ditch
I believe this clue is a double definition.
'make emergency landing' is the first definition.
(ditch can mean to land an aircraft on water)
'channel' is the second definition.
(a small channel or trench in the ground)
'in' is the link.
(Other definitions for ditch that I've seen before include "Dump; channel" , "Dump (informal)" , "long depression" , "Abandon - trench" , "Dyke" .)