Flat out after a mishap? Not unusual if you're this (8-5)
I believe the answer is:
accident-prone
'not unusual if you're this' is the definition.
The definition suggests a singular noun which matches the answer.
'flat out after a mishap?' is the wordplay.
'flat out' becomes 'prone'.
'after' is a charade indicator (letters next to each other).
'a mishap?' becomes 'accident' (mishap is a kind of accident).
'prone' put after 'accident' is 'ACCIDENT-PRONE'.
Can you help me to learn more?
(Other definitions for accident-prone that I've seen before include "Given to mishaps" , "Unusually susceptible to mishaps" , "Given to misadventure" , "Clumsy" , "Liable to have mishaps" .)