Make a mistake in flight, it's inferred (4,2)
I believe the answer is:
trip up
'make a mistake' is the definition.
(tripping up is a kind of making a mistake)
'flight it's inferred' is the wordplay.
I cannot quite see how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found within the answer.
The remaining letters 'ripup' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for trip up that I've seen before include "Blunder" , "Alpine excursion, perhaps" , "Catch out or cause to stumble" , "'Cause to stumble (4,2)'" , "fluff" .)