Zeva's tail-sitting one-person eVTOL flying saucer proposes to fling its pilot head-first through the sky at high speed, encased in a stamped-composite disc body that doubles as a lift-generating wing. It's far and away one of the strangest air taxi concepts we've seen, demanding some pretty extreme cojones of its occupants, but as we learned when we spoke to the company a couple of months ago, its unique form factor confers some interesting advantages that could overcome its obvious discomforts and make it a genuine contender in certain niches.