Flying danger has new sort of twin-set (6)
I believe the answer is:
tsetse
'flying danger has new sort' is the definition.
I can't tell whether this definition defines the answer.
'twin-set' is the wordplay.
'twin' shows that letters should be duplicated.
'set' becomes 'tse' (I can't justify this - if you can you should believe this answer much more).
'tse' doubled is 'TSETSE'.
'of' is the link.
Can you help me to learn more?
(Other definitions for tsetse that I've seen before include "flies" , "African transmitter" , "bloodsucker" , "cause of sleepiness?" , "fly across Africa" .)