Closer to Human Flight

negativeblue writes "Dropzone.com has (had) a story about the preparation of a man (Jeb Corliss) who prepares to land a wingsuit without a parachute. If you don't know the current abilities of parachutes, now-a-day, you should do your research. Basically airfoils, they can perform close to an airplane wing (high performance turns and lift)."

jeb is the man

[joatmon]

if you've ever seen a base jumping video 90% chance it was jeb.

...er...

[skinfitz]

If you don't know the current abilities of parachutes, now-a-day, you should do your research.

Shouldn't that be wingsuits? I should dearly hope that most people know the abilities of parachutes - they have been a regular plot device in the media for years.

Pics

[Anonymous Coward]

Coral Cache Links
http://www.dropzone.com.nyud.net:8090/cgi-bin/safe ty/jump.cgi?ID=556&view=Photo1 [nyud.net]
http://www.dropzone.com.nyud.net:8090/cgi-bin/safe ty/jump.cgi?ID=556&view=Photo2 [nyud.net]
http://www.dropzone.com.nyud.net:8090/cgi-bin/safe ty/jump.cgi?ID=556&view=Photo3 [nyud.net]

Speed is good

[Anonymous Coward]

The trick I think is to develop enough forward speed. More forward speed develops more lift. In a regular plane, you do something called a flare as you land. As you get close to the touchdown point, you steer up (technically, you change your angle of attack). This burns off forward speed and creates lift. This guy has a lot more freedom about his angle of attack. (Him landing on his feet would be the equivalent of a plane landing on its tail.) I think it could work but, of course, I'm not going to try it. My guess is that he will still have a lot of forward velocity when he has essentially no lift left.

The more I think about it, the more I think I agree with the parent.

Message from another aviation pioneer.

[JJ]

Don't Fly!! Don't Fly!!

You'll get too close to the sun and your wings will melt !!
-- Icarus

Re:...er...

[Anonymous Coward]

I don't think most people know the abilities of modern day parachutes. It has been a few years ago when I left the skydive scene, but at that time huge progress was made using new materials and designs. Modern parachutes might look like ordinary square parachutes, but there are some important differences: so-called 'zero-porosity' fabrics and high-tensile fibers, combined with elliptical shaped canopies result in very efficient parachutes. Some of those can be made *extremely* small (like the Icarus mentioned in the article). Smaller canopies result in higher speeds, but also in higher descent rates. Some of those canopies cannot be landed safely without diving for speed first (using so-called 'hook-turns' or 'front-riser' turns). Seeing somebody land a high-performance parachute is rather spectacular because of the speeds involved. The gap between flying the smallest of those high-performance parachutes (and the technique needed to safely land them) and flying a wing-suite is not that big anymore, and that is what the poster meant to say.

flybirdman.com

[kevin922]

http://www.flybirdman.com/ [flybirdman.com] all you wanted to know about wingsuit flight..

Toy Story?

[System.out.println()]

That's not flying... that's falling with style.

impressive

[moterizer]

For those who wonder what a wingsuit looks like in action, check out some of the videos on this page [objectjump.com]. I particularly enjoyed the one called "BirdMan on Monte Brento" which links to this other page [bird-man.com].

My other sig is funnier.

Re:Speed is good

[mattlyle]

yes, that's correct: a flare is just stalling.

under a normal parachute we flare every time we go to land... if you've ever seen a skydiver land, as they touch down you will see them pull down on two handles (called toggle)... these are connected to the rear of the canopy, which distorts the trailing corners of the canopy to create more lift... so you're converting forward speed into lift.

Re:There is a reason

[pi_rules]

The actual numbers, IIRC, are 1 in 100,000 jumps are fatal. The VAST majority of these actually operator error while nearing the ground on high performance canopies. For instance taking a steep turn using your risers when you're too low and smacking the ground at 60-70mph.

Malfs on your main parachute are 1 in 1000 from what I understood. Those are packed up in 5-10 minutes in a rather hurried fashion. Your reserve is carefully packed painstakinly by a FAA certified rigger who spends 30-45 minutes working on it VERY carefully. The reserve is also repacked every 120 days by FAA regulations.

I don't know the stats, but a double malfunction is a VERY rare occurance. It's more than likely "operator error" that causes the death of a skydiver.

Re:suggestion

[pi_rules]

a^2 + b^2 = c^2 -- works with velocity too!

70^2 + 30^2 = 5800.

Square root of 5800? 76.1mph. Pretty sure that's about how fast you're going after 700 feet. Just from memory, I've forgotten a lot of physics. Now, if you think a 700 foot drop into water is survivable.. well... at that point I don't think it matters much if it's concrete or water.

Besdies, have you SEEN one of these wingsuits? Go to birdman.com, they're the market leader. You are NOT going to want to swim in this thing. Especially not with a rig on your back.

Here, check this: http://justinbuist.org/images/120kmh_at_3meters.mo v

That guy is just a few feet from being able to land the thing on that slope, IMHO. However, he posesses some modicum of common sense it seems.

This has almost been done before (see the video). All that's needed is:
a) A slightly slower speed helps (slightly different suit than the Birdman stuff).
b) Some practice to perfect your flaring technique.
c) Somebody bat-shit crazy enough to think this up.
d) Somebody insanely bat-shit crazy to try it.

After watching a video I found online, I think this guy qualifies for friggen nuts: http://media.hugi.is/hahradi/fyndnar/jeb_2003big.w mv

Makes my butt pucker just to WATCH that.

Re:Speed is good

[spagetti_code]

You are right. And a little more detail is that he has probably got a low lift wing. Wing lift is proportional to velocity^2 * wing area * air density * lift-coefficient (basically aerofoil shape and angle of attack - AoA).

He's got a very small wing area so to achieve lift he needs speed, a high-lift wing shape and AoA.

He will likely have a high stall speed. (Note: you stall at an AoA, not a speed. But for a given configuration - weight, wing shape, bank angle, CoG, environment - the stall speed is constant.)

So he will be zooming along just above the ground at a high speed waiting for his speed to wash off - which it will, quite quickly because high-lift wingshapes are either very wide (large area, low cross-sectional thickness, low drag = glider) or very thick (like a wing with slats and flaps extended = high lift, high drag). Unfortunately he will need to increase his angle of attack to maintain lift, and he will still be going very fast when he 'stalls' onto the ground.

An alternative that comes to mind is the "zoom" - a sudden pull up that gains a few feet in a plane but also removes airspeed very quickly. If he times a zoom just right he might be able to turn himself into a airbrake without gaining too much height. Wouldn't want to do it myself.

Another is to live with the high speed and have wheels on the front of the suit. If you have landed a hang glider with wheels you will know what I mean - you come zooming in to touch down on wheels on the end of the bar you hold. You are lying inches from the ground as you roll.

Lastly, a comment on wing shape. He will want a very high lift from a small area, which means thick and high AoA. A good (for him) feature of those wings is high drag, so he will have the ability to remove high airspeed from freefall quickly. A bad feature is a tendency to stall if airspeed is not tightly controlled. I've just got this image of what a spin would look like...