How does Gilgamesh have a futuristic fighter plane? In the dogfight between Gilgamesh and Berserker, Gilgamesh rides a golden fighter plane that is capable of hovering and flying at great speeds, supposedly by harnessing some "strange green power" (see the opening wings and glow when Gilgamesh prepares to dodge Berkserker's approach). The Gate of Babylon is supposed to contain Gilgamesh's treasures of his time, so how did such a futuristic contraption come into his possession?
This "airplane" is the Vimana. It is recorded in several epic Hindu texts, including the Ramayana and the Mahabharata. In fact, in the original Sanskrit works, there is more than one vimana, but in any case it is a flying contraption that gods would ride. There is no record of them in Babylonian literature as far as I know, but of course Gilgamesh owns the prototypes for all of the technology that appeared in later cultures, which presumably includes this.