Such men go far up in the air (3)
I believe the answer is:
raf
'such men go' is the definition.
The definition suggests a singular noun which matches the answer.
'far up in the air' is the wordplay.
'up in the air' indicates an anagram.
'far' is an anagram of 'RAF'.
Can you help me to learn more?
(Other definitions for raf that I've seen before include "It fought Battle of Britain" , "Royal Air Force (abbr.)" , "Airforce of Great Britain" .)