Yet another confession: I am a helium head. That's what I understand they call them in the Air Force, anyway: people who are obsessed with lighter-than-air flight. Airplanes, forcing their way through the air with props or jet engines, do almost nothing to satisfy my craving for flight. What good is flying if you can't feel the wind in your hair, and can't hear the silence of the sky? I want to sail in the sky, not to motor in it. I dream of vast ships, constructed of high-tech filament and membrane, using the wind the same way a sailing ship does. They'd be transparent, barely there, like the jellyfish I've seen in Oregon Coast Aquarium, barely distinguishable from the water, using the water, not fighting it. My ships would use the air, the same way. Airplanes are capsules for transiting a hostile environment. They're for land beasts that really don't trust the sky. Like so much of modern industrial culture, they're essentially hostile to the natural world, wanting to conquer it, to tame it, rather than to understand it and work with it.
I've read that one reason German pilots were the most accomplished, early in the second world war, was that they nearly all trained as glider pilots first. They understood the air as an environment more sensitively than pilots accustomed to bulling their way through it from the start.
The ships would have to be huge. Forget jet packs and angel wings: they're for people who've never really thought about the physics of flight. A condor weighs 20 lbs and has a wing span of 10 feet; by plain arithmetic proportion a human being with a little gear would need a wing span of maybe 100 feet These are idle numbers – the progressions aren't arithmetic. Rigid airship builders reckoned that helium ships “broke even” at about eighty feet. To sail in the air you'd need to accept these proportions: you would be like those little dots, the nuclei of jellyfish, not like a superhero. If you wanted to carry other people, or freight, the proportions would of course be even greater. Most people I think lose visceral interest at this point. What good would flying be if you weren't the center of attention? But if you really play boldly with the scales, you realize that at really large sizes, the penny-per-mile cost of bulk freight could be astonishingly low. Grain to Russia? Bulldozers to Peru? Easy. Go straight there. Forget all the railroads and sealanes, the port costs. Pick it up wherever it is, take it wherever they want it.
I don't imagine my ships would ever land; possibly they'd never even anchor. You'd be winched up and down, maybe. You'd ascend through the gossamer sails and faintly prismatic wings, under the soap-bubble helium membranes, to find your place, check a few things, reef a sail or two there, extend a rudder membrane there, and set a spinnaker floating a couple hundred feet out to catch a thermal, and you'd be off to – anywhere at all.