British Airways unit making a lot of noise (5)
I believe the answer is:
babel
'noise' is the definition.
(I have seen 'Confused noise ' mean 'babel' so perhaps 'noise' could also mean 'babel')
'british airways unit' is the wordplay.
'british airways' becomes 'ba'.
'unit' becomes 'bel' (bel is a kind of unit).
'ba'+'bel'='BABEL'
'making a lot of' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for babel that I've seen before include "confused sounds" , "pandemonium" , "Confused noise of many voices" , "Commotion" , "Vocal confusion" .)