Despair brewing about jetBlue's latest flight rate (8)
I believe the answer is:
airspeed
'flight rate' is the definition.
'airspeed' can be an answer for 'rate' (I have seen 'rate of knots' mean 'airspeed' so perhaps 'rate' could also mean 'airspeed'). I am unsure of the 'flight' bit.
'despair brewing about jetblue's latest' is the wordplay.
'brewing' indicates an anagram.
'about' indicates putting letters inside.
'latest' suggests the final letters.
The last letter of 'jetblue' is 'e'.
'despair' with letters rearranged gives 'airsped'.
'airsped' enclosing 'e' is 'AIRSPEED'.
Can you help me to learn more?
(Other definitions for airspeed that I've seen before include "rate of knots" , "Velocity of a plane or missile" , "rate when flying" , "what Wellington could have got up to" , "Jumbo with such rapidity?" .)