What kind of wings would a person need to fly?

Question

I heard from a teacher in school that in order to fly, he would need a wingspan much wider than the wood shop where he was standing. Thinking back on it, I assume the number of times you can beat your wings should have something to do with it, since it looks like hummingbirds have shorter wings than eagles.

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What even goes into the computation to answer the requisite wingspan for flight, let alone how do you do it?

This may be like How to compute the speed necessary for an airplane to fly? but I think it's significantly different since flapping would be involved.

Also like Is it possible to fly like a bird using semi-motorized wings? but I believe also different because I want to know what wing size whereas that has a general flight/aerodynamics equation.

Finally: would people with no legs have an advantage in flying? (I assume this would be true if they weigh half as much and legs contribute no flapping power. Of course it could be different if you found a way to use leg strength.)

For a quick estimation, consider an average hangglider. But, are you able to lift your own weight by pushing your arms down? If not, you aren't going to fly today. — John Dvorak, Oct 23 '14 at 09:11
@JanDvorak: Even when flapping wings, the flapping provides propulsion while lift is provided by the wing aerodynamics. So your arms would have to provide enough power to overcome drag and some extra to allow gaining height, but never actual force to balance your weight. — Jan Hudec, Oct 23 '14 at 09:24
Related: Is it possible to fly like a bird using semi-motorized wings? — John Rennie, Oct 23 '14 at 09:29
Actually, it shouldn't have anything to do with frequency of flapping the wings unless the frequency is high enough to sustain flight in dynamic stall (which is only really a thing for insects). Hummingbirds most likely have longer wings for weight as the cube-square law works in their advantage. — Jan Hudec, Oct 23 '14 at 09:46
Try Heinlein's "The Menace from Earth": http://www.lightforcenetwork.com/sites/default/files/C6RAH3.pdf — DJohnM, Oct 23 '14 at 16:00
@JanDvorak Thanks. What should I consider about the hangglider? Is there an equation maybe? Or some physical constants? — isomorphismes, Oct 24 '14 at 07:45
@JohnRennie Yeah, I saw that one, and your answer linking to the Gossamer Albatross. I thought this was different because I was asking about wing size. — isomorphismes, Oct 24 '14 at 07:46
@John Dvorak - I can lift my weight by pushing my arms down ... but confusingly find I am unable to fly. Is there a special machine I can use at the gym to learn how to do this today? — Rob Lambden, Aug 08 '19 at 22:48

RedGrittyBrick · Answer 1 · 2014-10-23T11:24:35.343

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what kind of wings would a person need to fly?

long and thin.

^{Human powered flapping-wing aircraft (ornithopter)}

It seems this couldn't take off under human power alone but, once airborne, could produce enough thrust to overcome drag for up to 145 meters in 20 seconds of flight.

to achieve flight on the limited power of the human engine, the aircraft must be designed to fly quite slowly. At these slow speeds, the wing must be incredibly large to produce the required lift, and the structure must be incredibly light. To help support the light structure, external wire bracing is typically used, and although these wires add drag, the weight savings in the structure is significant. This wire-braced structure favours a hanging fuselage design, which is typical for human-powered aircraft. In the case of a human-powered ornithopter, the bracing wires are additionally used to pull the wing down during the thrusting portion of the stroke.

would people with no legs have an advantage in flying?

So far, most human-powered flights seem to rely mostly on leg muscles.

edited Oct 23 '14 at 11:24

answered Oct 23 '14 at 09:56

RedGrittyBrick

7,269

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Of course, most human-powered flights rely on leg muscles because they are huge and massive. It would be quite a waste not to use them. If you didn't have the weight of the legs, you'd have to do with your arms. Of course, you could just as well say that people with no arms would have an advantage :)) – Luaan Oct 23 '14 at 13:23
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@Luaan Don't forget midgets, or those rare people born with feathers, wings, and an aerodynamic body. They'd both be advantaged too – Jim Oct 23 '14 at 13:31
@jim can you please provide a documented case of such a person "born with feathers, wings, and an aerodynamic body"? I'm interested... – John Dvorak Oct 23 '14 at 15:38
@JanDvorak *Insert clever retort about it being a facetious comment here* – Jim Oct 23 '14 at 15:42
@RedGrittyBrick Right, the Gossamer Albatross and all the things linking from there on Wikipedia seem to be with bicycles. But I was thinking more like someone with a superhumanly strong chest flapping his/her wings of .. eg, a hangglider. Maybe a better way to ask it would have been do hang gliders with no legs have an advantage over legged ones. – isomorphismes Oct 24 '14 at 07:51
How would you compute how long the wings would need to be for a given weight of person? – isomorphismes Oct 24 '14 at 07:51
@Jim Short people are just the same as you and I. – isomorphismes Oct 24 '14 at 08:10
@isomorphismes can't disagree that they have less mass though – Jim Oct 24 '14 at 12:30
@isomorphismes: Your question how do aircraft wing designers arrive at the wing dimensions might get a good answer at aviation.stackexchange.com. There appear to be aircraft designers there. Other refs: 1 – RedGrittyBrick Oct 24 '14 at 13:21
@RedGrittyBrick Oh cool. There are more and more SX's every day =) thanks! – isomorphismes Oct 24 '14 at 19:28

What kind of wings would a person need to fly?

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