yuri_base

As a humble father of the new exciting sport - Theoretical Wingsuiting - I must say that I'm delighted to learn that my predictions work without the need to hurl myself from 'em perfectly good airplanes. You guys are my heroes - and you, Jarno, are the Number One - testing my theories without even realizing it, risking your life for the sake of my baby - Wingsuit Science! That said, look at the picture and rotate it clockwise 45 degrees, you'll see a 3-way flock.

You're talking about efficiency (maximum or at least decent L/D), which in this case - climbing above the plane as high as possible - is not... efficient (no pun). What is necessary is to maximize the force that pushes you up. Since in the first few seconds of high-speed exit your speed is almost entirely horizontal (the vertical speeds during the climb - 10-20mph are still much less than horizontal ~120-160mph), that force is lift. For most bodies - be it a superefficient glider, a slab of wood or a brick, the lift is maximum at around 45 degrees (+/-5 degrees). Stall is a significant drop of lift when AoA exceeds certain value (usually 10-15 degrees). After passing through the minimum, lift goes up again with increasing AoA and reaches maximum at ~45. And that's what we need for the climb. By the way, because our body dampens the lift/drag characteristics of the wings so much, overall we do not have that dramatic drop of lift (if at all) as airplanes do. The lift simply monotonically (although not as a straight line) increases from 0 at AoA~0, reaches maximum at ~45 and goes back to zero at ~90 degrees. Stall has nothing to do with airspeed. You are confusing powered level flight (where AoA to maintain level flight depends on speed) with nonpowered gliding. Stall is a function of AoA only. And "wingsuits don't fly at 45 AOA" is a 666th reason why flocking sucks, since that's typical AoA for most flocks (L/D=1). Yuri Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Even for most efficient wing profiles with infinite span the maximum lift at AoA of 10..15 degrees before the stall is about equal or less than the lift at approximately AoA=45 degrees (see this article). Most wings - and more so us in wingsuits - generate maximum lift at about 45 degrees - at 10..15 degrees or 30 degrees it's only a fraction of that of at 45. For climbing above the plane, it's the lift that matters, since initial speed is purely horizontal, so the drag which is opposite to speed, plays no role in your climb. Therefore, 45 degree pitch angle is the most efficient technique for the climb. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Cool!

It would be interesting if you do this modification and see the difference. The more experimentation, the better! What are you gonna lose? Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Still gay. Unless you're filming hot women's 4-way. Then you're my hero. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

High five, man!!!

I hope the owner of that ass not only will ask you for advice on how to treat it, but answer my question as well: how much these days is to install a third nipple? (with all my money spent on pitot tubes I can't even think about affording the fourth one, although that would be absolutely cool.) Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

It's not, indeed. It's aerodynamic science, not rocket. Perhaps, you were thinking rocket science when you made a bunch of physically incorrect statements in your book "Wingsuits in motion" (at least, 1st edition). From Chapter 1 "Aerodynamics" (sic!): Who "we"? As follows from above and below, not you. Drag keeps us in the air, too. In fact, it's 100% drag that keeps belly- and freeflyers in the air. With wingsuits, it's the vector sum L + D that opposes the gravity. In fact, at L/D = 1, drag makes precisely the same contribution to oppose the gravity as the lift does. First, not exponentially, but as a square of speed. Second, the lift increases in the same proportion, too. And third, we're not cars, so the speed is not determined by a pedal, it's determined by the very body position, so you can't say "I'm flying fast now, I must now make my body more aerodynamic." Cause and effect, eh? By definition, thrust is the force opposing drag, that is, pointing in the same direction as your airspeed. Belly- or freeflyer has [gravitational] thrust equal to his weight. In the above example of wingsuiter at L/D = 2.5 having drag of 14% of his weight, thrust is equal to 14%, too. In fact, the higher L/D, the less thrust you have to work with. Lift is perpendicular to thrust and the relation is the opposite of what you described: the less the lift, the more the drag, the more the gravitational thrust. Increasing angle of attack increases (up to a point, usually approx. 45 degrees) the coefficient if lift, not the amount of lift. (Don't confuse non-powered gliding with a wingsuiter pinned stationary in a horizontal windtunnel.) Past the most efficient AoA (which is, by my observations, about 10-15 degrees) when L/D is maximum, the amount of lift decreases and drag increases. See the formula above: L/D goes down -> D goes up, L goes down, the vector sum of L and D is still equal and opposite to weight. See above. L/D goes down -> you have more drag, less lift. Physics is not marketing, repeating "it has this AND this AND this" does not do you any good. Again, the amounts of lift and drag on a nonpowered glider in sustained flight are never changing in the same direction. Lift up, drag down, or lift down, drag up, but not "AND"! Selling the suits is not the same as physics of flight. Only in powered level flight. In nonpowered glider flight, lift and gravity are at an angle which is your glide angle. You can't be between 2 and 2.5 with 80 and 30, since 80/30 = 2.67. So, if you made so many physically absurd statements just on one page, isn't the problem that you "got captured in our own ignorance"?

By sticking the arm forward, you simply change the balance which with pants is shifted a little bit to your feet. It has nothing to do with the amount of drag created by pants but rather with center of of application of aerodynamic force. When falling straight down like freeflyers do, the drag is equal to your weight and does not depend on what clothes you're wearing. What baggy freefly pants do, they only change the distribution of drag. Whether you understand elementary physics or not. I witnessed an apotheosis of lack of basic aerodynamics understanding when I saw a couple of freeflyers watching the video of sitfly session in a wind tunnel. They were talking about cupping more air to get more lift. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

No, but when I saved enough money for sex change operation, I became more. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

I see a pattern now. Let me guess: it was you who wrote that piece in Skydiving magazine when Blade was introduced - that the new suit has "maximum lift and drag" (emphasis mine).

http://home.comcast.net/~clipper-108/lift.pdf Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

I don't know what you meant by "trick", but if it's level flight, 26lbs of thrust (P-60 has 13lbs of thrust) is not enough. For level flight, you need thrust be equal to drag. If your exit weight with engines and fuel is 200lbs, your lift must be equal to 200lbs for sustained level flight, and if your best L/D in a given suit is 2.0, that implies that the drag is D = L/(L/D) = 200lbs/2.0 = 100lbs. That's more like 2 P-180's or P-200's (45lbs of thrust each). With L/D = 2.5, you need 80lbs of thrust, 3.0 - 67. High L/D is crucial to achieve level flight with limited thrust. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Try to concentrate not on fallrates but rather on glide ratio. What you're describing are the symptoms of a low glide ratio. Angle of attack is the difference between the glide angle and your body's pitch angle, so if you're falling at 45 degrees and your body is level with horizon, your AoA = 45 degrees. You're in a stall, and that's the huge burble behind you that is rocking and rolling you. With time, you'll learn to be stable at high AoA and poor L/D, and that's called flocking. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Here's Z-Schlong It's long It's strong Stays up all night long But you better have a 2x2" square butthole to get any penetration. Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

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

Yo! Introducing Z-Device - a wingsuit flight characteristics measurement and recording device. It is capable of measuring directly at 10 samples per second: - total airspeed V - altitude Y - components Gv1 and Gv2 of apparent gravity (parallel and perpendicular to velocity, respectively) - components Gp1 and Gp2 of apparent gravity (parallel and perpendicular to pitch axis, respectively) - temperature - (optional) GPS data (4 samples/s) From the raw data, these flight parameters can be derived: - horizontal and vertical speeds - glide ratio - L/D (which is not equal to G.R., in general) - adjusted lift and drag coefficients Kl and Kd (and from them, sustained horizontal and vertical speeds for given body position and AoA, and thus - polar curve) - angle of attack - lift and drag as functions of AoA At the core, Z-Device is based on this idea: if an accelerometer is mounted on a vane, the ratio of the components of apparent gravity perpendicular (Gv2) and parallel (Gv1) to the airspeed is equal to [acceleration corrected, true] L/D: L/D = Gv2/Gv1 In addition, vane allows one to mount static and dynamic Pitot tubes accurately pointing into the relative wind and thus accurately measure airspeed and altitude. The vane is mounted on a collapsible pod on the belly so before the jump you extend it about a foot away from your body into the clean airflow where it tracks the relative wind. Another accelerometer is installed on the bellymount and the relative readings of the two accelerometers allow one to calculate the angle between the relative wind and body's pitch axes - that is, the effective angle of attack. Temperature is measured by a temperature sensor to make corrections to altitude and speed data. Optionally, GPS sensor can be installed that samples 4 times per second. However, with accurate and true air speed and accelerometer data, GPS can be useful only on BASE jumps. Also optionally, speed, descent rate, and accelerometer readings can be viewed in real time on a wireless dashboard that can be mounted on belly or chest strap. For electronics, I used the wonderful Eagle Tree Systems Flight Data Recorder. (The accelerometers I am using are not the ones advertised on their site (which have +/-38g range and are not very accurate, they're custom-made with +/-1.7g chips, providing about 0.005g accuracy)). The total cost of electronics is ~800 bucks. I made 3 jumps with Z-Device in Z-Hills on New Years Eve, the results so far are promising. The vane is rock stable - no wobbling, it just sits there quietly pointing into smooth relative wind. However, 1ft from the body may not be enough to get the vane away from the boundary layer, as on one jump I could see that the vane got stuck pointing more horizontally than it should have. I will investigate this by attaching wool threads to the stick at different distances from the belly and see where the air becomes 100% clean. I couldn't calibrate accelerometers due to software issues, so the accelerometer data I got was garbage. This needs more work. The data will be processed using Kalman filter based on wingsuit equations. We'll see some amazing stuff in 2008!!!

What's the value of this for us? Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

...is born!!! Tested the prototype today at Z-Hills. More details and data when I'm back to New York. Happy New Year, fuckers!

Jarno, you're my hero, BUT! You forgot one thing... The invention of a new revolutionary discipline in wingsuiting: the Theoretical Wingsuit Flying!!! Yuri TWS #1 Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Correct. It was math, physics, ENGINEERING, and a LOT of $$$ that sent humans to the Moon. You forgot a few men with HUGE BRASS BALLS. ...and degrees in engineering. They surely engineered the most funny puppet show ever created! Astronaut jumps and salutes flag Astronaut and dust obviously move at different g's. Dust - some of which is launched up with the same speed as astronaut - should land simultaneously with him, yet we can see it's all gone by the time he reaches the apex. That's because the dust is not suspended by strings. That's also why you never see them do big jumps - the difference in g's would be too apparent. The reason they appear to be moving like puppets, stand up after falling with center of gravity apparently outside of support (25s mark in this video) like puppets, is... because they ARE puppets on strings! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Jarno, you are my hero (this completes my December 2007 payment of royalties for your amazing artwork on the left ). BUT... Why are you so sceptic about human flying like an insect??? We can make YOU fly like one, and you don't even need to use your legendary brains! We have innumerable technologies for augmenting your strength (clown shoes and animal balloons are just two of them). The force of gravity and the minimum input from your muscles and tendons are enough to power your furious flapping. It is a simple matter of applying faith and philosophy to the problem. We will make you so strong that you'll move massive boulders from Stonehenge to Belgium without using lube and ponies! We will then reduce you in three dimensions to the size of a chicken and superimpose you over the skeleton of a bat. And then... then we'll unleash the crazy ponies and see you take off like a hummingbird! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

See, this example emphasizes what's wrong with wingsuit development. 1937 - airplanes are already quite sophisticated, they are tested in wind tunnels, aerodynamics is a well-developed science. Airplanes of that time are already engineered to fly well. Yet, wingsuit "pioneers" of that time, like zombies, follow the same dumb pattern: "let's strap something to our arms and legs to resemble bats or flying squirrels". Doesn't matter what it is, what the state of the art of aerodynamics is now - let's strap a sheet of fabric and "fly"! Total disregard to thinking. You're in 1937 yet you're borrowing from the designs of 17th century. Or you're in 2007 and borrowing from the designs of 19th century. It's like a Wall Street firm run by people who can't even add 5 and 7 without a calculator. So the answer to the question "What will the future wing suit resemble?" is: "It will resemble whatever somebody knowledgeable and talented in aerodynamics will say, "What the hell is wrong here??? Are these people all fucking retarded? Let me do something about it!" Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio

Just by watching the video, it's obvious that the suit is so misbalanced towards the head-high stall that it should be considered a small round parachute with some forward movement. It's the ParaCommander of the wingsuit world. To balance this suit, you would need to wear my Magic Shoes on your head, Jarno! Android+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio