Part of a flight leads to sudden turbulence, alerting inbound runway (5)
I believe the answer is:
stair
'part of a flight' is the definition.
(I've seen this before)
'leads to sudden turbulence alerting inbound runway' is the wordplay.
'leads to' suggests taking the first letters.
The first letters of 'sudden turbulence alerting inbound runway' is 'STAIR'.
(Other definitions for stair that I've seen before include "Tread and riser" , "One step of a flight" , "Word linking way and well" , "One of a flight of steps" , "A step on the way up or down" .)