This dude can fly, what are the Physics?

Question

Take a look at this video clip: http://www.youtube.com/watch?v=PmZyB_ghpa0

What are the Physics? What weather conditions are best to fly and why? Could he land without a parachute and live, and if so, how? Is he insane? Is this Awsome?

Here is another clip where he flys within inches of a cliff: http://www.youtube.com/watch?v=ttz5oPpF1Js&feature=related

At one point in this second video, the dude comes within twenty feet of a car on a road making a hairpin turn. If he collided with the car, could he knock it off the road?

[Note: Have to keep the questions related to physics ;-)]

The guys in these suits have been able to get glide to drag ratios of 2.5:1

Everytime I watch these videos, I am amazed. The speed, daring and control of these jumpers is incredible.

The physics are simple aerodynamics and fluid dynamics. But people aren't birds. How a person can adapt to flying with such ease is amazing. (I guess I can body surf fairly well, which is similar)These suits have been around since the 30s. The lore is that most of the orignial innovators crashed and burned.

These jumpers can slow their descent to the 25-60 mph range, but they are still moving 100 mph horizontal. Good example of lift and drag. Also, in the first video, the jumper is kicking up snow with his ground effect (thereby demonstrating his lift).

There is a competition to see who can be the first man (or woman) to survive landing without a parachute. http://www.gofastsports.com/zone/wingsuit.html . Frankly, you just need to hit some place soft, and that you don't break your neck or other parts

For more, see: http://en.wikipedia.org/wiki/Wingsuit_flying

Answer 1

The principle is not much different from the aerodynamics involved in an adjustable plane wing. The difference is that he cannot generate any forward thrust. His only driving force is gravity. Then he uses that wing like webbing between his legs to deflect the air. This is how he achieves the horizontal motion. It is NOT because of any initial horizontal velocity remaining constant. In skydiving the air resistance is so large, you lose any horizontal velocity very quickly. It is also very difficult for him to move vertically upward. A sail boat can adjust its sail to move against the wind, but a sail boat does not have to overcome its own weight in doing so.

His top speed is roughly 120 - 180 mph (terminal velocity of a sky diver). Let's say a man's weight is 1/20 times that of a car, then he has the momentum of a car traveling at 6-9 mph, but a lot more kinetic energy. It's not going to catapult the car if he crashes into it. It may topple it depending on the angle of impact, but it's more likely to dent it severely and break some windows... as well as some bones.

The best weather conditions would have to be when it's not gusty, because that would make it difficult to maintain control. And can he land without a parachute? Yes, but he'll die doing so. That device he has can only deflect the air, it can't create the air resistance the way the canopy can. He needs the parachute to land. In fact I've heard of people who died on impact even though their parachute did open. That's because they didn't slow down in time. So without the parachute, forget it.

Some other interesting questions would be:
What's his maximum angle of flight?
How far would his guts spill if he crashed?

Is he crazy? Well that depends on how you define crazy. Some people think having a day job is crazy and would much rather do something fun with their life. Hey, he's on youtube and I'm not.

Answer 2

This has some good answers already, but I'll chip in. Think of dropping a paper aeroplane straight down from some sufficiently high platform. As it drops, the variation in the air resistance (point of the aeroplane versus the wings) with redirect the falling object from a mainly vertical decent to include a horizontal component.

As for whether he is flying or not, he is more appropriately gliding. His decent, which does reach a maximum speed due to air resistance, will slow in a purely vertical sense, but not by a lot. He seems to be falling more slowly simply because of the increase in horizontal motion. It's not too unlike the principle of orbit, which is a continuous fall cancelled by the earth's curvature.

It is theoretically possible that he can survive without a parachute. It has happened in some rare cases. However, he'll likely have a harder time as impact the ground very quickly but in a horizontal sense. If he does survive, that will be one nasty burn.

As for impacting the car, it is a matter of the transfer of momentum from one object to another. As the first video implies a speed of 100 MPH roughly, a 200 lb man would impact the car with a decent force. I suspect that a small car that's travelling in the same direction might be pushed enough to knock off the road, especially on the hairpin turn. Any other type of impact would probably not. It's a matter of calculating the force vectors at play.

The question of insanity is a legal one, not a psychological one. If he were insane, I doubt that he would be allowed to participate in this awesome (yes, awesome) hobby. He might have an underdeveloped sense of self-preservation, but that's not usually a bad thing. :-)

Answer 3

According to me it's simple Aerodynamics....and my logical mind says that if u see the guys r wearing wing like outfits, ofcourse such a patter similar to the birds spread of wings is definately going to make any guy fly, for that matter even u cud fly if u know how to balance ur body as per the air pressure and it's flow.

For eg. When u ride a bicycle u need to balance urself and maneuver ur driving as needed, the same thing applies here, flying is also mage balance of ur body in the air and with the gravitational force.

Ofcourse at higer altitudes the air pressure is going to control ur body movements but once u come off the air pressure and get in the force of gravitational pull fully u will fall down and thats when the guys open their parachutes.

U need to observe birds when u appreciate these guys. They r not insane coz they were passaionate and way too intelligent to observe the birds and then learn their flying physics :D, a good observer will always know how the birds balance their movements in the air and the way they glide and flip their wings, If i observed properly i indeed see the guys move their hands and body the right way as any bird wud do.

The summersault was something a bird does when it goes daring and needs a good thrill :D lol

Answer 4

OK, first, this dude does not fly.
Second, you can do this yourself if you want, try looking into it :D

But to answer your questions:
Physics is: He is being pulled down by gravity, but he is acted on by air resistance (increased by the little wings he has). So as he jumps out of his helicopter, with an initial translational velocity, which is not lowered much during his fall (in a fake world, it stays the same, so i'll use this for explanation). So as he falls, gravity pulls him down, increasing his vertical velocity, and increasing the air resistance (which is proportional to his velocity), until they equalize each other. At that point, he just about does not accelerate, so he keeps falling down and moving forward. This speed at which equilibrium is reached, is so high, that if anyone hit the ground, they would automatically die, so he has to release the parachute, so it will catch the wind, and slow him down. You could probably make some kind of a contraption to catch him without a parachute, but I have not heard about one yet. He is not insane, this is although not common, its well known. It is similar to sky-diving. Best conditions for doing this... no wind or small wind in direction you want (you have to plan). And this is kinda cool :D I am leaving out the fact that he can move his body, so it steers him in the air, but kind complecated, and would be best understood through actually doing it (as I never did). Then, your question about colliding with a car. I don't really know, but most of his velocity is downwards (the pictures are taken at an angle, making him look like he is flying) and very little to sideways, so if he actually hit the car, he would make a dent in it, and would die. But, if, now that I saw it again, you say that he hits the car head on (car is on a really high incline), he would collide with the car, stick to it, and push it. How fast he is, his mass, and the mass of the call will factor into how far he pushes the car, but you can guess at that by using the equation: his mass * his speed = (car's mass +his mass) * car's final speed.
Otherwise, I don't think many people can answer your questions.

Answer 5

in case you have multiple questions a pair of real plane, ask away. yet once you have questions a working laptop or pc interest ask someplace else!!!!!!! reason the plane subject be counted isn't a reliable place for faux pilots or pc programers.....it somewhat is in basic terms that some human beings at here save encouraging FSX human beings again returned here ......i could say not crammed with faux pilots, yet if you consider that mike's at here w/ an ton of faux bills/troll friends i think of that is a lie

Answer 6

I got a rush just watching that second video! Imagine doing that in real life!!!

Worth the risk? Maybe.