Let’s say some ultra light-weight prosthetic wings were engineered for human use. I’d imagine the flapping mechanism might be powered by both leg and arm movement to ensure the amount of energy the human can put towards wing flapping is maximised.
How close could a typical human being get to lifting off?
There’s this attempt:
As a pedal-powered flapping wing airplane, it might not be exactly what you’re looking for.
They talked about this on one of those learning channels.
In order to get the power you would need, you’d need something like a twentyfoot wing span. And get this, your chest muscles would have to be six feet in diameter.
Ehh, I wouldn’t count that thing. The vast (pretty much all) of its lift is from a large conventional airfoil (i.e. a wing). It had to be towed to initially get into the air, and it’s not clear how long after untethering it could maintain flight via its ‘flapping’ motion.
There was a video of the first human powered hovering helicopter about a year or so ago, but even that was sort of a cheat because it relied too much on ground effect for lift.
How much actual force is that? Would it be possible to add mechanics that could augment the human generated force while still being lightweight enough to hypothetically fly?
Eh, I don’t know. I was working off of a years old memory.
The only reason I remember it at all is because they did a cheesy computer animation of what a human would look like in order to fly by just flappiong his arms/wings.
I found it slightly creepy and amusing.
No. You cannot use mechanical advantage to improve your power/weight ratio - you can just move that power around and apply it in different ways.
Top cyclists can (apparently) manage 6W/kg - you can fly with that sort of output (Gossamer Albatross and similar) but it is pretty close. And the only muscles in the body big enough to do that are the quads.
Top rowers may get close to 6W/kg through their arms/chest, but they need to use their legs as well - I don’t think you could usefully convert rowing motion to flapping in a stable manner.
The only possibility I can see could be a yacht grinder, who put out massive power through a hand crank (more stable than a rowing action). However, I think they train for power, and weight is not generally a major consideration. Grinding is also not a endurance activity, as you would need for sustained flight.
Si
I’d count it - I think it’s a useful example of how nearly-impossible is the challenge
Really? That seems almost ideal to me - some sort of rowing-machine contraption with a sliding seat, in which the pilot-engine pulls repeatedly on a two-handed handle attached to a cable. As long as the required wingbeat frequency is equal to the rower’s stroke frequency - which it could be with a large wing.
For something as light as a manpowered aircraft, having the major proportion of the mass moving almost a meter will be hard to cope with. Also, the instantaneous load for rowing are massive, stressing the seat, rails, and footrests. Trying to keep it light but strong enough will be a real problem.
That said, I would go for oar handles with outrigger pivots and a mechanical linkage, with the wings pulling forward to keep the CoM as stable as possible.
Good point, but there might be a way to design that mass shift in and exploit it as a feature (maybe to change the angle of attack mid stroke - seating the pilot-engine facing backwards, if necessary)
I worded that badly. What I meant was, would it be possible to build a machine powerful enough to do that extra flapping necessary that’s small enough to fit on a human and lightweight enough to plausibly fly? Obvious answer seems to be no, but I’m still curious as to the actual force involved.
An ornithopter-pack! It’s a brilliant idea, but I suspect an engineering nightmare.
Six feet? The heaviest flying bird was Argentavis, which had a wingspan as large as you describe, but its body (height, including legs, and weight) was only about the size of an average human. Also, the same article says that you can lift up to 25 kilograms per square meter with avian flight, so a human could get away with about 2-3 square meters. Of course, human muscles aren’t adapted to the motions needed for flight, but if you allow some machine then it sounds plausible (and are flapping wings the most efficient form of flying?).