Go too far above one in flight (8)
I believe the answer is:
overstep
'go too far' is the definition.
(I've seen this before)
'above one in flight' is the wordplay.
'above' becomes 'over' (I've seen this in another clue).
'one in flight' becomes 'step' (part of a flight of stairs).
'over'+'step'='OVERSTEP'
(Other definitions for overstep that I've seen before include "Transgress" , "Exceed" , "Go past (the mark)" , "Go beyond (a limit)" , "offend at the crease" .)