Particular flyer's articulations being excellent (3,4,5)
I believe the answer is:
the bees knees
'excellent' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'particular flyer's articulations' is the wordplay.
'particular' becomes 'the' (referring to a particular example of something).
'flyer's' becomes 'bees' (I can't explain this - if you can you should give a lot more credence to this answer).
'articulations' becomes 'knees' (knee is a kind of articulation).
'the'+'bees'+'knees'='THE BEES KNEES'
'being' acts as a link.
Can you help me to learn more?
(Other definitions for the bees knees that I've seen before include "Just the very best" , "Outstandingly good thing" , "A corker, a humdinger" , "joints used to crawl with insects?" , "Ideal person, event" .)