To eject from plane is not catastrophic (8)
I believe the answer is:
jettison
'to eject' is the definition.
(thesaurus)
'plane is not catastrophic' is the wordplay.
'plane' becomes 'jet' (jet plane is a kind of plane).
'catastrophic' is an anagram indicator.
'is'+'not'='isnot'
'isnot' is an anagram of 'tison'.
'jet'+'tison'='JETTISON'
'from' acts as a link.
(Other definitions for jettison that I've seen before include "Throw (into the sea)" , "21 [OFFLOAD]" , "bin" , "Abandon, discard" , "Ditch (cargo)" .)