FlyU6 is an airline in Grand Theft Auto: Chinatown Wars. It is only known because of FlyBoy, who supposedly is an employee of FlyU6, who sent Huang Lee an email suggesting FlyU6 as an airline of choice.
In the FlyBoy's email sent to Huang, FlyU6 is said to have teamed up with the NOOSE, in order to give away free tickets to "rogue states" such as Afghanistan, Iraq, Libya and nearby countries with all expenses paid.
However, in the last lines, he writes: "When booking, please note that FlyU6 will not sell-on your private details to criminals, hackers, or terrorists (outside of the US)."
The airline's motto is "Don't delay, book today."