Aerobatics feat (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
loop
'aerobatics feat' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for loop that I've seen before include "ring road, say" , "(Of aircraft) make a circle vertically" , "Branch line" , "I cross myself" , "Noose" .)