Missile trailing plane produces wreckage (6)
I believe the answer is:
jetsam
'wreckage' is the definition.
(jetsam is a kind of wreckage)
'missile trailing plane' is the wordplay.
'missile' becomes 'sam' (SAM is an example).
'trailing' means one lot of letters go next to another.
'plane' becomes 'jet' (jet plane is a kind of plane).
'sam' after 'jet' is 'JETSAM'.
'produces' acts as a link.
(Other definitions for jetsam that I've seen before include "lost cargo" , "Cargo deliberately thrown overboard to lighten ship" , "stuff washed ashore" , "that's been dumped overboard" , "Floating rubbish" .)