I’ve loved airplanes and rockets forever. I studied aerospace engineering in school. But one thing has always bothered me. You know that dream where you swish over the treetops or hop from one neighborhood to another with your mystical flying powers? That kind of flying is serene and beautiful.
But that’s so distant from reality. Real flying machines do extreme violence to air:
It’s not immediately obvious why flying machines have to be so violent. For example, suppose we hang a generic flying machine from the bottom of the Golden Gate Bridge. As long it’s connected to the bridge, all the forces are static. We are at rest hanging below the bridge, and no energy is required to hold our machine in mid-air. The situation is serene.
Suddenly we cut the cable. And the physics switches from rigid, static forces to fluid dynamics. This leaves us five options to avoid crashing into the icy waters below the bridge.
Become buoyant and just float.
Shove air downwards as fast as it slips away (classic aerodynamic lift).
Generate an as-yet-unknown anti-gravitational force.
Generate a magnetic field opposing the Earth’s magnetic field.
The third option is science fiction. The fourth option would wreak havoc on compasses, electronics and nearby metal structures… plus the required magnetic field is so strong that it’s also science fiction.
So we’re stuck with buoyancy, and shoving air down.
Buoyancy requires our flying machine to be big and really flimsy. With all of San Francisco’s blowsy fog swirling around beneath the Golden Gate, being at the mercy of the weather seems pretty terrifying.
But if we want speed or control, we’ll end up with a real air-pounder.
These systems produce so much noise and have so much kinetic energy that they can’t be used safely to dart around the city. If helicopters were used for much more than e-vacs and the occasional tourists, we’d be driven mad by the noise.
What I really want is something in between. Something that’s quiet and safe, but still speedy and agile. To fly around unimpeded by stupendous amounts of machinery. That would literally be a dream come true. Is such a thing even possible?
I hardly know the answer :)
But one old aircraft idea has always intrigued me: the Deltoid Pumpkinseed. The Pumpkinseed was a hybrid airship, basically a fat flying wing full of hydrogen or helium. The idea is that the lighter-than-air gas inside the wing gives some buoyancy, so the plane needs less aerodynamic lift (less shoving air down.) Hypothetically you get the best of both worlds: less machinery to keep you in the air, but still a high degree of maneuverability.
The Pumpkinseed was tested in 1971 by Aereon Corporation, but it lost out on funding – it seems there wasn’t a clear use case for it at the time. It’s a fascinating story.
Recently though, a real use case has appeared for the Pumpkinseed: surveillance in Afghanistan. You may even notice that the Lockheed Martin P-791 airship built for that purpose bears some striking resemblances to the Pumpkinseed.
But clearly this is diverging from what I (you too?) really want. A personal flying device that doesn’t produce an insane amount noise… though this is damn pretty cool:
Maybe what I’m really pining for is the days before the Hindenburg, when you could catch an airship across the Atlantic in real style. Serenely floating over the North Atlantic, the engines hundreds of feet behind you and completely quiet, just the sound of the air rushing by. Reading a book as you slip over English pastures… That sounds like real flying to me.