Macross Zero (OVA)
Shin Kudou, a young U.N F-14 pilot and the main character of the story gets shot down by an unknown enemy ship during a sortie and crash landed on a solitary island.
Coincidentally, an unusual energy reaction is detected on the island, and the energy reaction might be originated from the Protoculture's superior technology legacy which was brought by the extraterrestrial at ancient times. This technology legacy is very similar from the recovered fallen extraterrestrial battleship eight years ago.
Now, both of U.N and Anti-U.N are going to invade the island for the quest of recovering the legacy and the superior technology it posesses...
(taken from Animenfo)