KrisFlyZ

Bummer...Hope you get well soon. Kris.

That may be true. If we are talking about wingloading. The shorter lighter(in our example 6'6", 160 vs 5'4" 100 lb) person has a lower wingloading. The lighter person wins in a floating race(until strength becomes an issue) no doubts there. When it comes to glide, I can only comment if both people are built the same...then the lighter person has an advantage(having been both people myself...90kg vs 73 kg). Kris.

Can you give some information on the bigwalls in the north and on the hikes? I have been preparing for the hikes and hope to visit Northern Norway this year. Kris.

Two courses are offered. 1) The full course...if you do this forget about jumping pants until Elin releases you from student status. 2) The short site specific prep course. For people with more jumps that just want to know the site specific details. Since you have a few more than 15 jumps(I think)...you have the option of doing the site specific course. I took the FJC last year and jumped in street clothes for the first few jumps. A safe distance from the wall can be tracked in 12-15 secs without the need for any tracking garb. If 6-7 sec delay objects are not available, heli or balloon jumps if possible, if not, tracking skydives are possibly the best practice. Kris.

He rig? Is that in development? Can't find it on the website. Kris.

Anyone using this .... feedback please. I have seen people use Spectra on BASE canopies for slider up jumps. Any more info regarding how this(spectra ) has worked so far in the field? Kris.

So are the cherries and the berries. Take your own food and beer and spend a week or two over there. It costs about the same as any other trip. If you are going to do do something stupid like jump off of cliffs anyway...do the hikes they are good for you. Kris.

Exit technique has a major affect on how soon a flight is initiated. I have seen skinny light people in big suits do worse than 200 lb folks in beginner suits. It was also evident(to anyone watching the exit technique) why the skinny person was burning up so much altitude to start flight. Personal observation. =============== V1@90kgs and Phantom@72kgs...flight reached pretty close to max in 10-12 secs. It is my belief based on being in between 72 and 90 kgs(nearly 6'2") and having flown the Phantom throughout this range that 72 kg is too light. It was more comfortable to fly when weighing 78-80 kg. Kris.

Well said. Kris.

By fly this discussion means glide ratio(L/D). The discussion is also relative. How do you glide in comparision to someone of the same height but 130 lbs lighter? As humans we are programmed to compare. I have been speaking about average glide and not about steady state glide. This is more easily observed in real life. We can see who opened the farthest(and to some extent higher...from canopy time) much more easily than who has the best L/D. Assuming the weight and shape has no affect on L/D(steady state). In terms of average glide the much heavier people are at a disadvantage. It takes longer for them to get to their best gliding speeds(see Yuri's post on Fat vs Skinny and perceived performance). And due to their weight they also get to spend less time at their best L/D which screws up overall glide. As an example Flyer 1 : Skinny Exit altitude: 1000m Gets to best L/D of 2.5(50m/s fwd, 20m/s down) in 200m(altitude lost) has an L/D of 1 up to this point. Flyer 2 : Heavy Gets to best L/D of 2.5(75m/s fwd, 30m/s down) in 400m(altitude lost) has an L/D of 1 up to this point. For an opening altitude of 200m Flyer 1 can fly for a further 30 secs and his average glide is (200 + 50* 30)/800 = 2.125 Distance covered 1700m. Flyer 2 can fly for a further 10 secs and his average glide is (400 + 100* 10)/800 = 1.75 Distance covered 1400m.

Just got the book. Read Chapter 7. Very interesting. Kris.

sounds nice :) I was thinking that it is not a good name ...especially if it is used for BASE...but then again BASE jumpers have a dark sense of humor. Kris.

We were talking about how Cl and Cd are determined by nothing other than shape of the wing. If that is the case, how well someone can glide is only determined by their physical characteristics(wing properties). This discussion was about how Cl and Cd would change with weight and height. Where did skill come into the picture? What do you mean by skill? The ability to hold a certain angle? Aerodynamically speaking, the only thing(because other than the suit and rig we cannot change our physical characteristics...not instantaneously anyway*) that affects Lift and Drag and thus L/D is the Angle of Attack. What is the skill needed to stay still and hold an angle? For all people of the same height the person with the longer legs and shorter torso has the most area. Someone with long legs and short torso has an advantage because the balance of the suit(if the proper suit is chosen) and the bigger legwing naturally puts the flyer at an optimal AoA. Kris.

I am most likely wrong about the otter. I don't know where you got the idea of favourites. Why are you trying to apply the conditions that you stated, incorrectly(same shape and CG is impossible to achieve at different weights in humans) to humans? That is what I assume this thread is about. If not, I have nothing else to say. How much weight can someone gain before it changes their shape? 10kg? 20kg? 50kg? Does gaining weight change the shape for the better? Your argument that because it applies to airplanes..it applies to humans as well is wrong. Kris.

O.k, bad example.... If we take humans...99+% stall flight. Drag will increase with velocity(square) but lift will not == poor glide with increased weight. Because more weight = more velocity. O.k honestly, I am just blabbering. Kris.

Argh, I just said this in another thread. SPEED does not equal GLIDE. Comparing a powered aircraft's climb rate at different loadings has nothing to do with glide. An unpowered Otter, with the same CG and different loadings, will glide at exactly the same slope. No it won't...the Otter is also a crappy glider(phenomenal compared to humans but by glider standards..crappy). The gliders we talk about as gliding at the same glidescope but different speeds on increased weight are super efficient, super low drag flying objects. We are super inefficient wings(2:1) and we cannot convert that increased weight to lift as an efficient glider(70:1) would. There are also other implications in humans to increased weight that make the inefficiency even more(in most cases). http://en.wikipedia.org/wiki/Glider Kris.

The question we started with was different. Will the same person if he was 5 inches shorter and 10kg heavier make a poorer glider than the original? Kris.

Check with Klaus if Paralog with GPS works on Palmtops. Paralog works on Palm PCs. Don't know if Paralog with GPS does. www.paralog.net(or IM Vidiot on here). Kris.

You are absolutely right, we are crappy airfoils. This is the explanation I have in my mind...may not be right.... Jeff N, flying almost as well(or better) as the others in the single skin suit. Can you guarantee that the flight is at a super efficient AoA? My bet is that it is in a stally configuration.... AoA = ATAN(D/L) (-/+) pitch (-/+) Angle of Incidence AT 2:1 GR this is 26.5 degrees(at lower glide the angle is even bigger)....at this AoA, the double skin suit will effectively become a single skin suit of lesser area. Can't answer that theoritically. Kris.

You are right Chuck. My bad, I did not make the point properly. And very good point on too small is more difficult to fly than too big. Just trying to say this... Get a suit too big and your performance, consistency will suffer. We can stretch our body to an extent and fill out a suit that is slightly big, a few more inches bigger and it becomes impossible to fly it at the same efficiency as the suit that fits us well. Kris.

Contact info is on the www.pressurized.at website. Kris.

Sorry for the long winded post. That suit is no potatobag. It has the right balance. i.e. It will put the flyer at an AoA closer to optimal. I owned an S-Fly and liked it very much. It is for sale(in classifieds on here ) now by the guy that purchased it from me. He has the same problem as me with it. He is an exact replica of me in height, Torso length and Inseam. The suit seems a bit wide across the legs(I laughed when I saw that in the classified text)...actually the problem is that the legs start a bit lower on that suit(as our torsos are shorter than that suit is designed for)...when that slack propagates down it becomes impossible to fly the legwing without flap. This is a symptom I have had on my last 4 suits. It took me two years to figureout the problem. While talking about fit of the suit here is another interesting one. When I purchased the Phantom, I weighed nearly 90kg with a big belly(remember that halloween pic, Matt). It fit me quite well then. Now, I weigh 73kg..after reducing the length by an inch and a half the suit is still about two inches or so loose in length. On the flip side, whan I purchased my V-1, I weighed around 80Kg. Gaining the extra 10Kg helped me fly that V-1 without flap on the first jump....among other things. Because the extra length was taken up by the girth. Don't believe me...try and get someone the same height(smaller Torso length and same leg length)as you but of more girth to wear your suit....I will bet you money that the suit will end up short on length. The extra width translates to length. I cannot put this in words but its something about volume and the suit taking the dimensions of the volume filling it....rather than having a definate shape. Extra length makes flight by relaxing the legs(or not stretching the legwing very tight) impossible. It has been published that to fly for max glide one must use a relaxed body position. The theory that I can come up with is that a relaxed body position allows the wings to make a bow(left to right...don't confuse with camber) and the airflow under the wing presses it up. In the 3D sense this gives the air over the top surface the best chance to stay attached...while creating clear channels underneath. See Robi flying in the Phoenix-fly promo video from 2004...the one with all the jumps in China? We can see the legwing forming a nice arc as well as pressing up...this pushes the butt deflector up rather than flatten it. IMO, Even with the thinnest of rigs the butt deflector needs help to do its job well. In the attached pic...the arm wings need to come in quite a bit more. The well inflated Butt deflector has not covered much of the thickness of the rig. This picture was taken in the first few secs of the jump and the legs are relaxed...normally the legwing gets tensioned a lot more. When we create lift with an attached airflow on both surfaces(usually the upper surface is a problem) the sensation is so obvious...it will be almost like being hit by a Mack truck in the face. For me this happened on the first WS BASE jump for a few secs and never again. That is why I kept thinking it was somehow related to having total concentration. Now, I know that this is near possible to reproduce without a suit that fits perfectly. Why? a) Flap is bad and it kills performance. b) Extra length or girth translates to flap. c) When we create camber(rolled shoulders and spine pushed up..gut sucked in) our lenth reduces...even with deep cut booties. To push spine up and have the suit cling to the body the torso of the suit must for perfectly and have no empty space. c) A suit that fits an inch and a half or so loose cannot be flown relaxed without flap. IMO, to fly for performance the suit fit is of paramount importance. Baggy does not work when it comes to wingsuits. Even the most skilled pilot cannot fly a suit that is just a few inches too long. If you have read all this sorry for wasting you time . Kris.

The first time I flew a Prodigy at ZFlock 05....it was the prodigy legwing and tracking jacket. I had no issues with going head down or anything*. However, as Matt said...what is true for me and you may not be true for a newbie. Kris. *It took me a long time to accept the headlow angle. Contrary to what Ed says. Sometimes you have to let the suit fly you . Ofcourse Ed may have been speaking of a different suit when he said that .

So did I when I posted the pool . Left it as it was anyway. Kris.

Tracking ======= In tracking skill weighs in much more(because the efficiency is so low)...the size of the rig is a huge factor. Search up HooknSwoop's post on tracking. A thinner rig is a huge factor. Skill indirectly translates to a smaller rig in tracking. Most brilliant trackers are people with thousands of jumps and tiny rigs. Now give them a Mirage M4 with a 176/170 and compare their performance vs themselves flying the smaller rig. Wingsuit ======= Come on Matt. You know better than that. 10 kg heavier person is a thicker air foil. Shorter increases Aspect ratio by how much? A few hundredths. Aspect Ratio ========= This is Square(span )/ Wingsuit Total area. Don't calculate as Span / Chord. Aspect ratio if you want to get technical(in a wingsuit position for a given height) depends on Inseam to Torso distribution. Long torso for same available height is a worse aspect ratio in the wingsuit flying position. I calculated this in a spread sheet(if I remember correctly) 4 inch longer legs(normal is 42) at 61 inch suit length meant a 2 percent increase in aspect ratio. Does that even matter? Area of the shorter person is much smaller(in a relative sense). How much does 4 inch reduction in height reduce the wing area by? 4 inch reduction in inseam(36 inches to 32 inches) will reduce leg wing area by 25%(assuming a constant 58 degree angle for the leg wing across sizes). Also 5 inches shorter is 5X shoulder measurement less area. ===================================== Anyway, increased span is only additional drag in Wingsuit flight. In flocks, the additional area The wings of current wingsuits are flown with the arms significantly in (or span reduced) in order for the wing to not deform. ===================================== After all this conjecture we have two facts. a) Yuri is among the top few WS pilots for glide. He says himself that he is not the best build for WS flying. Skill is a big factor. He is also superstong so strength is a big factor. b) I flew back from Smell (in the Phantom) and pitched over ground. That is a 2+ average glide. Am I that skilled(300 ish WS jumps of which 200 jumps were for time or flocking and 15 WS BASE jumps at that point)? Or is build an advantage? Just so this isn't misinterpreted. The point of a) and b) is....without argument skill is important but don't discount the advantage of a proper build either. Kris. Edited to all link