Grant airworthiness certificate perhaps, and send out (3,3)
I believe the answer is:
let fly
'send out' is the definition.
'let fly' can be an answer for 'send' (thesaurus). I'm unsure of the 'out' bit.
'grant airworthiness certificate perhaps' is the wordplay.
'grant' becomes 'let' (I've seen this in another clue).
'airworthiness certificate' becomes 'fl' (I am not sure about this - if you are sure you should believe this answer much more).
'perhaps' becomes 'y' (I've seen this in other clues).
'let'+'fl'+'y'='LET FLY'
'and' is the link.
Can you help me to learn more?
(Other definitions for let fly that I've seen before include "Launch an attack on someone, verbally" , "Fling" , "Attack verbally or physically" , "Attack; throw" , "Burst into tirade" .)