I this is indeed a "blade" antenna. It is probably some variation of a monopole, maybe with some sort of "top loading" intended to make it appear "electrically" longer and hence operate at a lower frequency than the physical length would allow. You might also call it a monopole or loaded monopole. The flat surfaces are probably driven by aerodynamic issues rather than electrical. A round wire has about 10x the drag compared to a airfoil hence the streamlining.