Aircraft in the morning abandoned cargo (6)
I believe the answer is:
jetsam
'abandoned cargo' is the definition.
(I've seen this before)
'aircraft in the morning' is the wordplay.
'aircraft' becomes 'jets' (jet is a type of aircraft).
'in the morning' becomes 'am' (AM on a clock).
'jets'+'am'='JETSAM'
(Other definitions for jetsam that I've seen before include "Goods from ship washed ashore" , "may be washed up" , "found at sea" , "that lands on shore" , "Material discarded" .)