Aircraft abandoning its initial path (4)
I believe the answer is:
lane
'path' is the definition.
(lane is a kind of path)
'aircraft abandoning its initial' is the wordplay.
'aircraft' becomes 'plane' (plane is a kind of aircraft).
'abandoning its initial' means to remove the first letter.
'plane' with its first letter taken off is 'LANE'.
(Other definitions for lane that I've seen before include "Narrow track or path" , "way" , "Narrow street" , "Rough path" , "Small road" .)