Fails to start flying on operations (5)
I believe the answer is:
flops
'fails' is the definition.
(flopping is a kind of failing)
'start flying on operations' is the wordplay.
'start flying on' becomes 'fl' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'operations' becomes 'ops' (abbreviation).
'fl'+'ops'='FLOPS'
'to' is the link.
Can you help me to learn more?
(Other definitions for flops that I've seen before include "Falls flat" , "Slumps" .)