Yet in Frank Herbert’s Dune (and subsequent books), ornithopters are a key mode of transport throughout the universe.

Why?

We know that after the Butlerian Jihad, thinking machines were outlawed (although I’d argue that rule gets bent a lot – the hunter-seeker dart that tries to kill Paul and Mapes seems to cross the line). However, that doesn’t mean that aircraft should be banned. Any World War II vintage aircraft would be fine, as probably would any aircraft up to the beginning of this century if not further (and thus any aircraft that existed in Frank Herbert’s lifetime).

So why ornithopters? The technology predates helicopters and well as airplanes, having been designed and tested at least as early as the thirteenth century. It’s not a case of the story making the author’s technology outdated, Herbert knew airplanes and helicopters.

Ornithopters are less fuel-efficient, less load-bearing, and more problematic than either. That’s why the concept has been mostly abandoned.

Worse yet, ornithopters are inefficient even by the Dune universe standards.

We know that they have anti-gravity. Baron Harkonnen and the Sardaukar all wear anti-gravity belts. Surely a spice harvester should be equipped with such a technology and not be waiting for an ornithopter to pick it up. Surely the personal aircraft of the Duke of the planet should use this much better, if not state-of-the-art, technology.

There’s a lot in Dune that’s about the race to improve humanity, not our technology (again, the Butlerian Jihad influence), but still the discrepancy of the ornithopter is odd within the Dune universe.

I can think of only one reason to include it and make it a key element of the universe: Frank Herbert thought they were cool or exotic and would make the story memorable in some way.

And honestly, I can’t argue with that.