physically, what is stoping humans from having “flying bicycles”?

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“Japanese Student Takes Flight of Fancy, Creates Flying Bicycle” [https://www.youtube.com/watch?v=ZJrJE0r4NkU](https://www.youtube.com/watch?v=ZJrJE0r4NkU)

*Edit: Far beyond regulations and air traffic control issues, only regarding to physics:*

I’ve just seen this video of a Japanese student that has achieved making a flight of about 200 or 300m with a mechanism that turns the pedalling we normally do in a bicycle to the turning of a propeller.

Now, if we as humans and a very great bike can reach 40-50 mph (and very light planes such as cessna can take of with only 60mph – not to mention Bush Planes – all of these weighting easely 4 to 5 times the weight of a person + an extra light airplane design, specifically created for that porpouse) – why does this seems too hard to achieve/sustain? I can only guess its a matter of efficiency (or the lack of it), but which one of them?

In: Physics

34 Answers

Anonymous 0 Comments

Biological muscles are demonstrably capable of powering flight. The capability has evolved 4 times, after all. But all flying vertebrates have had to evolve lots of tricks to ensure their muscles are capable of generating enough lift. Most commonly known of these is “hollow” bones. Not exactly right, and they have more purposes than just keeping weight down. But the trade off is still there – fragility. Humans have solid, less fragile bones, as well as denser bodies and more fat.

There have been aircraft powered by humans, as others in this thread have mentioned. But they aren’t practical for regular use. Not on this planet, anyway. Maybe you could custom-build one for an incredibly lean and fit, but still very small person to use regularly in very flat terrain. But they wouldn’t be able to carry cargo, and would be pretty wiped out after any extended flight.

For impractical, recreational uses, larger people who are nevertheless still fit could probably use them for short flights, especially if you could find a safe place with good thermals to fly at. But if you’re going to do that, hangliding exists, and doesn’t require such engineering or specific environmental conditions – just a cliff and a well-constructed metal and cloth piece of equipment.

Now, a flying e-bike might be plausible. You can get a bunch of power out of an electric motor, and just keeping moving while in the air requires less energy than taking off or performing complex maneuvers.

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