The Mystery Of Hanwags, or How To Fly Phantom at 2.9

[Costyn 0]

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If you change the position of the center of mass you change the trim, and if you change the trim you change the performance. Maximum glide performance in a glider is usually obtained with the most rearward C of M you can get away with before running into stability problems.

My airplane has a 7 inch range of permitted C of M between max forward (flare becomes difficult) and max rear (potential instabilty). That's in a 2500 pound airplane. I imagine the range is far less in a human size flying machine. On an average person, adding 4 pounds to the feet will move the C of M back about an inch.

Ah ok, that makes sense. Thanks for the informative post.

Problem in a wingsuit as I see it is that a stalling wingsuit will not drop out of the sky as would an airplane, but will start to act as a round parachute, by just cupping air right?

If so, for flying most efficiently, I would think it would be useful to have a stall warning on a wingsuit as on an airplane. Then you know when you are no longer flying but falling. Or am I totally off the mark?

edited to add: a round parachute, not a square obviously.

Costyn van Dongen - http://www.flylikebrick.com/ - World Wide Wingsuit News

[The111 0]

The other thing missing from the picture is that C of P on a wingsuit is completely variable, unlike on a rigid-wing glider. I would think a small tweak of your body/wing position could alter your trim as much as adding a small amount of weight to your feet. And I'd much rather just adjust my body than fill my shoes with lead.

www.WingsuitPhotos.com

[yuri_base 1]

Brian, I agree: it could be trim, extra smoothness of well-stretched fabric, balance, magic of clown shoes, or all of the above. I won't be flying in the next two weeks, so you're the Principal Investigator of the Mystery of Clown Shoes. I'm interested in seeing the results of your experiments, you're an incredible flyer. I'm sure that given clown shoes big enough, you'll fly at 5.0 with the fall rate of something-teen.
Yuri

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[tr027 0]

With big enough clown shoes, even pigs will fly just fine!

"The evil of the world is made possible by nothing but the sanction you give it. " -John Galt from Atlas Shrugged, 1957

[yuri_base 1]

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P.S: What do I need to do to get cute russian chicks?

That's easy. All you need to do is to appear on Brighton Beach in New York in humongous clown shoes and Vampire in the middle of a hot and steamy weekend day, when naked Russian Chicks melt in the sand like cheese. Just walk around and say that your L/D is better than that of a parachute. Chicks will stick to you like melted cheese to shoes.

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[yuri_base 1]

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If you change the position of the center of mass you change the trim, and if you change the trim you change the performance. Maximum glide performance in a glider is usually obtained with the most rearward C of M you can get away with before running into stability problems.

My airplane has a 7 inch range of permitted C of M between max forward (flare becomes difficult) and max rear (potential instabilty). That's in a 2500 pound airplane. I imagine the range is far less in a human size flying machine. On an average person, adding 4 pounds to the feet will move the C of M back about an inch.

I totally agree. Since human body was not created to fly, our CM is probably too much forward relative to wings (especially for those with big brains ). It's like your plane with CM at the forward end of that 7-inch range. You still can fly, but you have to trim the plane excessively with the tail, making it overall less aerodynamic. Same with wingsuit: we think that we can max it out just by adjusting the body position, but we might still be outside of that perfect trim.

Yuri

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[nathaniel 0]

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clown shoes

Flippers!

My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

[Costyn 0]

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Flippers!

Haha yeah maybe wingsuiters can start wearing flippers to use as extra wing area or elevators. That might be just crazy enough to work.

Only problem is the derision from fellow skydivers would be even worse.

Cheers

Costyn van Dongen - http://www.flylikebrick.com/ - World Wide Wingsuit News

[BenediktDE 2]

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Only problem is the derision from fellow skydivers would be even worse.

On our dropzone the birds are called penguins - the flippers would fit. :-)

For every complex problem there is an answer that is clear, simple, and wrong.

[KrisFlyZ 0]

I looked at your GPS data.

Why is the horizontal speed continuously reducing?

In your log the speed falls from 104mph(sec 18) to 79mph(sec 41) and keeps falling until deployment. This is hardly a sustained form of flight.

Attached are graph pictures from one of my phantom flights. Notice that the speed in the 23(15 secs after exit from the airplane) to 48 sec (this is when preparation for the turn back to the DZ starts) segment is smooth(there is no data smoothing algorithm applied). The variation in horizontal speed is about 5 mph in 26 sec vs 25 mph in 20 secs in your case.

The overall glide from your jump is 1.91. This jump was from a balloon, what is the reason for considering a segment of the jump only?

Kris.

[diablopilot 2]

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maybe im wrong, but when im flying at 18,000' in the kingair, it has a lot of trouble keeping up.

Prtable GPS units have alot of trouble in the rear of GA aircraft, the antenas don't usually have an undisturbed LOS>

Oh and what country are you making these "legal" single parachute jumps from A/C?

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You're not as good as you think you are. Seriously.

[mccordia 73]

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Oh and what country are you making these "legal" single parachute jumps from A/C?

I think people fall out of balloons a lot, and just happen to be wearing a single parachute-system...

JC
FlyLikeBrick
I'm an Athlete?

[diablopilot 2]

Right, and I've done it as well....nothing remotely legal about it.

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You're not as good as you think you are. Seriously.

[yuri_base 1]

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Why is the horizontal speed continuously reducing?

As soon as I felt the quietness of the air, I stopped leaning forward hard to go for speed and started flying more relaxed, in a totally flat body position trying to keep this wonderful quietness. So I stopped accelerating and instead entered the slow flight mode. It turned out to be also the best glide mode.

After 35s into the flight, I stopped really flying and was looking for the place to land. I stopped looking down between my legs and looked forward. Arched body position lead to decreased forward speed and increased fall rate. At 44s into the flight, I closed my leg wing to slow down before the deployment and at pull time I was falling more or less straight down.

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[The111 0]

Too bad you didn't go to Russia... your "2.9" could have blown away Loic's and James' measly sub-2.0 glides.

"It's not the pilot, it's the shoes!"

www.WingsuitPhotos.com

[yuri_base 1]

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"It's not the pilot, it's the shoes!"

Exactly! Maybe someday Phoenix-Fly and BirdMan will sell special clown shoes with depleted plutonium inserts. "When Performance Matters"...

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[The111 0]

I was being sarcastic.

www.WingsuitPhotos.com

[yuri_base 1]

More thoughts.

Suppose you are tracking at L/D = 0.8, that is, at 50 degrees to horizon. If you are in a flat track body position, with your body almost parallel to horizon, the angle of attack is 50 degrees. Very bad aerodynamics -- you're in deep stall.

To track more efficiently, you have to go headlow to decrease the angle of attack. If you're 30 degrees head low, the angle of attack is 20 degrees. Looking between your toes, with shoulders rolled forward and moderately low angle of attack, your 'wing' is much more aerodynamic. Your speed increases, the air is hitting you from ahead of you, instead of from below, and you feel that you're producing lift, not just drag.

Hence, the technique is born: gotta go headlow, spread your legs, push the butt up, go 'superterminal'.

Now on to wingsuits. L/D is much better to begin with.

Suppose you are flying at L/D = 2.2, that is, at about 25 degrees to horizon. If you try to go headlow, e.g. 20 degrees to horizon, your angle of attack is only 5 degrees. You can't achive maximum L/D with such a small AoA.

Can you achieve L/D = 3.0 with headlow body attitude? You're flying at only 18 degrees to horizon now. There's no 'room' anymore to go headlow.

So for wingsuits, the 'superterminal' technique doesn't do any good as it does for tracking.

Rolling shoulders forward and tucking your head in (looking between your toes) is necessary to create efficient aerodynamic profile. This naturally puts you in headlow position, determined by the balance of center of gravity and aerodynamic forces. But then AoA is too small to achieve the best L/D.

I see two ways to solve this catch-22.

One is to balance the body using weights on your legs. ("When Performance Matters, Gotta Wear Clown Shoes!")

Another one is to design wingsuit with about 15 degree angle of incidence (angle between the wing's chord and the line of your body). (See the illustration of this idea here.) The body will need to be balanced headlow at about 15 degrees to horizon. The wings will have about 15 degrees AoA. Placing the body completely in-line with airflow will reduce the drag dramatically. This suit will be much speedier than flying in clown shoes, yet it will fly at maximum L/D possible.

Yuri

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[tr027 0]

Uh, I still think the secret is all about the shoes. We should try to get Nike to make a WS shoe and call it the 'Air Clown'

"The evil of the world is made possible by nothing but the sanction you give it. " -John Galt from Atlas Shrugged, 1957

[Professor 0]

Yuri, this seems very unlikely. Let me explain why.

The biggest GR number I've ever heard quote for the phantom is 2.5. The biggest reliable GR number I've ever heard quoted for any suit is 2.7 for the V1. These numbers are from some of the best pilots in the world, guys who have 100s or 1000s of WS jumps jumping just for performance, guys who are built well for flying, guys who design wingsuits, guys who jump in base rigs, aerodynamic helmets and Hanwags all the time. And now here you come, with considerably less experience, and a less-than-optimal build, and say you can sustain 2.9 just by throwing on a pair of 'wags. Somehow, that seems very unlikely. Somehow the idea that you dusted the best flyers in the world, simply by putting on a different pair of shoes, doesn't really make sense. Especially considering those pilots are already wearing the same magical boots.

However, there may be some buried truth here. I'm sure the phantom was tested and tuned quite a bit with hanwags, and I wouldn't be surprised at all if Robi tunes suits to fly their best in the base environment, since it's really more important and more noticable there. And that would include tuning the suit to fly best with Hanwags. So I think if you'd posted and just said "Hey guys, I just did my 1st jump with Hanwags, and had one of the best flights of my life. Anybody else notice this when flying with boots?" you'd have gotten a bunch of people agreeing. But throwing out outrageous numbers like 2.9 is just going to make people roll their eyes.

Ted
Like a giddy school girl.

[Calvin19 0]

Dude.
what makes you think im in the rear of the kingair?

CH
Single and Multiengine commercial instrument pilot

i mean, the man took my ticket away from the injury, but ill get it back in a month or so.

[Calvin19 0]

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My airplane has a 7 inch range of permitted C of M between max forward (flare becomes difficult) and max rear (potential instabilty). That's in a 2500 pound airplane. I imagine the range is far less in a human size flying machine. On an average person, adding 4 pounds to the feet will move the C of M back about an inch.

I completely agree with your statment, the sailplanes i fly have a water tank in the tail, and in the wings, we fill them with as much water as we deem necesary. I also fly the towplanes, and when the glider is heavy and tail favoring, its gets really fun. normal tows are at 60kts. we do those at 80. sometimes its hard for those guys to keep her steady even then.

but of course, your aircraft and a wingsuit are very different. a wingsuit is designed around a human body. the human body was not built to fly, even though with NO wingsuit i have seen paople achieve a track of almost 2/1 GR. the wingsuit is an extremenly variable flying machine. its as if we put full variable wings, Horizontal stab, and every hinge in between on a Duo Discus. granted, DD are at their best possible flying performance already, and are locked compositly into that state, but a human doesnt have to land, we are not a high aspect ratio flying platform. quiet the opposite actualy. we can change our angle of incedense without thinking about it, our pitch angle, and severale other relative wind profiles. From the drawings i have done of a wingsuit, its 4 wings, and the payload, the CG is already WAY behind what a ridged flying machine would be. it has the CG and wing profile of an F16. and anybody who knows about that aircraft, knows about the computer systems it takes to fly. humans, are impressive.

[yuri_base 1]

Also, on the same token, shifting the center of mass forward should be advantageous for tracking. When CoM is trimmed to make you headlow, the legs can be brought together - this way they will produce more lift than mere round tubes.

Lead jackets, anyone?

To summarize, people with big brains and small balls should be great trackers, and people with huge balls and no brain should be great wingsuit fliers.

Yuri

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[KrisFlyZ 0]

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Especially considering those pilots are already wearing the same magical boots.

Robi's word for shoes that do not allow the ankle to articulate was 'crap'.

Ted's explanation is a reasonable one but at the same time the numbers he is comparing to the ones posted are apples and oranges.

When we hear 2.5 in the BASE world, it is an average number from a standing start.

The 2.9 posted by Yuri is not an lie or calculation error, it just has to be taken in context. His calculation of glide starts at a speed of 104 mph.

As an example, in college I was running the 100m in 11.2-11.4 secs....a flying 100m (or the 100m timed by starting 10m behind the line and timing the last 100m ) was 10.4 secs.

10.4 secs may get a spot in the asian games 100m finals, 11.4 is good for nothing.

If we extend this thinking, it is soon obvious why even with wind correction applied (this is as far as I know a very original thing Yuri came up with and deserves a pat on the back for...Well Done!!
When jumping with a GPS we need to be very careful how we use the data. Question everything.

Kris.

[dploi 0]

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Robi's word for shoes that do not allow the ankle to articulate was 'crap'.

I wholeheartedly concur from a lot of experience, not one magical flight. Hanwags = drag. Great, great shoes for all their other obvious benefits, but their rigid form is not conducive to flight.