The trick is to fly for 60 seconds (if ure lvl 100, or 40 sec otherwise) and queickly, only when no one is looking, sit for about 10 sec (make sure the mobs dont get you) and fly again.
Make sure you keep this quiet (dont tell anyone) and make sure no one in labs sees you do it (neither other charecters or the monsters) or they will steal the secret... my secret... my preccciiiiouuuussssssss.
On a more serious note, if you could fly forever, then im pretty sure that someone would record you doing so and report you to a GM... account band :(