Type that is for attack (6)
I believe the answer is:
sortie
'attack' is the definition.
(I've seen this before)
'type that is' is the wordplay.
'type' becomes 'sort' (I've seen this before**).
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'sort'+'ie'='SORTIE'
'for' is the link.
(Other definitions for sortie that I've seen before include "Military aircraft's flight" , "Short foray" , "Military foray" , "Military raid" , "Short trip; attack" .)