“Vá soltar pipa/papagaio”?
Tradução certa? Literalmente, sim, as o equivalente de GO FLY A KITE em português é VAI TOMAR BANHO, VAI VER SE ESTOU NA ESQUINA.
Ex.: “This fellow was a total bore, why not tell him to go fly a kite?”
Ex.: Go fly a kite and stop bugging me.
Ex.: Harry was tired of his girlfriend's advice and told her to go fly a kite.
Ex.: Why don’t you just go fly a kite?
O website Goenglish.com comenta:
You say “go fly a kite” to tell someone to go to another place and do something different; leave here (agressive). Example: “Oh- not you again!” Reply: “Hey, why don’t you go fly a kite?”
Go fly a kite can be considered rude or aggresive because you are abruptly telling the other person to go away
Fonte: Pitfalls: 500 Armadilhas da Língua Inglesa de Jose Ricardo.