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Everything posted by robibird

  1. RIP Coombesy. You will be in our thoughts forever. Wish to say to OZ BASE gals & guys that I am with them at this dark time. Robert Robert Pecnik
  2. For WS flying jumper can use the canopy he jumps the most. The better you know your canopy, you can better handle your canopy deployment and opening. There is no need to go for bigger canopy if you know how to pack and if you know the rate of sensitivity of the canopy you using. Regardless if it is Stiletto, VX, FX, Radical, Pilot, Spectre,... any canopy can present you with problems. No one can say that any particular type of the canopy is the best for WS flying. In my opinion, there are two ways how to deploy the canopy: 1. Vertical descend mode (I am using that one in skydiving. I jump FX 82.5 and Radical 95, both are elliptical and one is CB canopy) After the flock is done, make the break off, than slow your horizontal speed and get your self in to vertical decent as much as possible, i.e. try to become ''normal'' skydiver, falling straight down. Than pull the PC, and from that point everything follows as usual, like in regular skydive without WS. IMPORTANT!!! In order to ''kill'' horizontal speed, minimum transition time is 5-6 sec! Very often you see flyers to slow down only for second or two, ending in the worst situation for pull & deployment. IN WS flyer does not slow down completely, the canopy will be opening during transition flight from "horizontal" to vertical, which is creating the area of high turbulence behind WS flyer. 2. Pull in the full flight mode (I am using this in BASE) Fly max or average flight in terms of glide ratio, pull and MAKE sure that shoulders are square, and that your body does not bend during deployment, inducing unintentional turn. This is the common mistake, and if the pull sequence is not done properly, this unintentional turn will result in line twist (trajectory of your body and canopy during deployment is not the same, and one side of raisers will have more tension). Proper packing is imperative for good openings in WS flying. I am strongly advising that you pack the canopy by yourself, because you will pay particular attention to specific needs of WS canopy openings. Robert Pecnik
  3. my comment is - bummer !! ...and that comment would apply to anyone who would try and end up caught like Jeb did. Such object can't be classified as regular object nor the person who dare to jump can be blame for object burning... Would be the best to stop all that big drama about it. Jeb for sure knew the risk and the consequences and now he is dealing w this in the best way he can. For those who attacking him for object burning I can only say that in few weeks or bit longer they will have a chance to try to jump... and probably will be stopped. I wonder why no single base jumper who is so against Jeb haven't try to jumped since Thor... Envy or jealousy, or?! Robert Pecnik
  4. robibird

    New rig..

    head, head has to be removed !!! I found that years ago when the human flying started!! Robert Pecnik
  5. ____________________________________________________ By adding deflectors, you are sacrificing that efficient, laminar flow for a "more sticky", but less efficient, turbulent flow. How do you know when that trade-off becomes worth sacrificing the laminar flow? Or is the flow always going to be turbulent due to the fact that wingsuits typically aren't very smooth surfaces? ___________________________________________________ in short
  6. robibird

    New rig..

    Robbie P - kad ces mi napravit jednu? ;) Tom, Upravo radim na gore opisanom... ali kao sto znas, ja idem van kada je stvar gotova, testirana i spremna za prodaju!! Lijepu vecer zelim tebi i tvojima !! :) Robi Robert Pecnik
  7. robibird

    New rig..

    First of all, every effort in body flying is very welcome because we are such small community. :) As far as the WS and WS specific rig issue goes, I can say following: The WS extreme was designed in order to provide the jumper fine balance between maximum performance and versatility. BASE jumper can use that rig for both slider up or slider down jumps, and will be able to climb antennas, chimneys, sneak through the buildings, and this rig will suit him 100%. Rig designers had a hard task to find that balance, because most of the jumpers want one rig and canopy (money issue ) which can provide them with best performance & safety regardless of the object type. For example, combination of WS extreme and V1 or P+J will provide that optimal result. Easy to use, hike, climb.... Performance is, of course, top level. However, there are many things which can bring the performance on higher level too, but it is the question of ratio between complexity vs. efficiency. This is the main point which personally I always have on my mind. However, many jumpers are working on their equipment in order to reach better performance...France, USA,, Lucky are those who can do that !!!! Norway is wonderful place for BASE flying. Topography of Norwegian cliffs is offering you more space to play than any other place. Other places have different limitations and demands. Therefore, designer's task is to find optimum for each piece of the equipment. Aerodynamic aspects of such long rig can be discussed as well, but this is a different issue... Regards RoBi Robert Pecnik
  8. completly wrong Jarno lower pressure is on the upper part of the wing, and nothing but this will keep the deflector open. Same principle apply to any type of any deflector or air inlet on WS. The only thing which may keep the deflector or air inlet closed or out of function is the improper position, wrong size, wrong shape or wrong material. Robert Pecnik
  9. Hi, There are a few misconceptions on mylar: 1. It does not improve pressurization 2. It does not help unless you are flying the suit efficiently, meaning you only see the benefit of mylar ribs when you flying the suit towards maximum performance. 3. It does not have the same purpose as the ribs on cross braced canopies. Mylar does not make the profile more rigid (in terms of the connection of top & bottom surfaces like the cross braced rib system does) The advantages of mylar are: 1. It helps to keep the right profile of the wing on the first few seconds on BASE exits 2. It reduces the vibration of the trailing edge of the wings, which directly affects the flight characteristics. This is the primary reason of having the mylar. Robert Pecnik
  10. I always use exactly the same pull up cord for that kind of thing (actually, I've recently switched to using a clamp, since it's harder to forget it in there). I mean _exactly_ the same physical pull up cord. If you stuck it in a bag of pull up cords, I'd be able to identify it. I've had people "borrow" it while I was packing, and I've ended up running around trying to find it, and not closing until I had it. I use that same pull up cord (again, exactly the same one) to close my top pin, so if it's missing when I close, I start looking for it. I had a friend who used to use a pull up cord to pack his PC (he died in a wall strike that was not related to this practice). He always used the same pull up cord, and he'd tie it around his MLW when he finished packing. Before exit, he'd look down, and if the pull up cord wasn't there, he wouldn't jump (no kidding, I once saw him back off because he didn't have the pull up cord, even though we checked his PC and it was fine--it turned out the pullup cord was in the trunk of the car). my god!! Tom, all this story you wrote above is excelent example how to complicate your life! One of the better ways to stay calm on the exit is to forget about the tools and learn to pack tool free!! I offten seeing people fighting with the packing and with the tool as well Personaly I never even close my rig w the same pull up cord-can't find it after one packing
  11. Hello, As this discussion is quite interesting I think it is important to emphasize a few things: IMHO it is very important to draw a line where the track suit ends and WS begins. Personally, I was involved in designing and flying both. I like to define the Pants as clothing which helps to provide better flying characteristics, but that MUST still allow you to walk, climb and land easily. To assure this the user must be able, while standing on one leg, to touch their chin with their knee (moving the knee toward the chin) If they cant do this then the "pants" are not pants any more, they are a wingsuit leg wing. It is also important to note the difference for what is important to BASE jumpers and skydivers (rarely they aim for same goal). Human body flight has at least two different directions: flying for time and flying for distance (and recently a skilled handful of jumpers fly for "proximity" with the objects) In BASE they fly for distance and it is very obvious how far you go, how good or bad a flight is. In skydiving that is not the primary goal (unless one really goes for it, wearing GPS etc) Having the data recorder with time only, usually gives the wrong perception of what is a good flight, unless you are only interested in time..... Y-base mentioned the angle of incidence (angle between body and wing ) To assure more lift this angle is very important. However it is hard to say what is the best placement because each jumper has different body proportions, CL and CG is in a different place. In theory each jumper most likely would have different AI. If you move the wing attachment line more to the front (towards belly) the suit will be slower and more prone to stall. It is very wrong to look at the WS as the three wing system. It must be taken as one piece. With changing the angle of incidence in the way Y-base said the body will not fly under lower angle of attack! What will happen is that the wings will have a higher angle of attack; meaning that it will fly very close to stall position. ********************************************* Current wingsuits have wings inline with the body. This sets the same angle of attack for both the wings and the body. The body is as efficient aerodynamically as a log due to its low aspect ratio and shape. That's why birds and airplanes keep the body/fuselage inline with the air flow, to reduce the drag as much as possible and let the wings alone generate the lift. ********************************************** Incorrect. In low speed aviation angle of incidence is up to 6 degrees max. Not "much" but not the same as fuselage. Also the fuselage generates lift, of course it depends on the type of the plane.... Cessnas not at all but F-14, F-15, MIG-29, SU-27 a lot!! In WS & human flight the body generates a lot of lift, much more than people think... Robert Pecnik
  12. another one :) Robert Pecnik
  13. I see that people are experimenting with the Prodigy legwing (without the armwing). I would like to say following: Phoenix-Fly does not recommend using the Prodigy legwing on its own because it could cause unstable head low exits (due to lack of lift from upper body). If you wish to ignore the manufacturers advice make sure you practice extensively from the aircraft before taking it to the cliff. I watched the VKB boys in action last year at the Heli Boogie together with the Kjerag locals and some of the OZ boys too. For both groups I can say that they are master trackers and are really pulling 100% from their pants, regardless of the type they have. Distance and precision are definitely related to their equipment but much more to their skill. The VKB boys have the unique opportunity on this planet because of the cliffs they have in their home yard. In northern Norway the cliffs allow a different tracking style than in other places. The ''Energy management'' is different, the high vertical walls allow you to dive and build huge amounts of speed before you plane out to fly down thousands of feet of steep talus. In the rest of Europe, jumpers are forced to use little bit different technique, that also suits a different set up. There is many ways to get good results. Each set up has its pros & cons. Bottom line is to get used to the set up you use and get the experience before doing such demanding jumps. Good luck to all
  14. :) Regardless of hours of training and skils, we all need to respect the comfort level of other participants. Once one is in the air, we all expect from him to respect our life and his own life as well. This is the basic rule why we have opportunity to do something what majority of the human kind think is stupid anyway :o) Robert Pecnik
  15. Buzzing.... zum-zumm - it is fun!!
  16. hello, In order to make better performing WS, which is the very long process, smooting and cleaning the leading edge is crutial element. Every single time when WS had better ( cleaner ) leading edge testing results were better and better. I don't know what percentage will make you happy, but I am happy by any % of the speed vs.drag I can get. Does the helmet helps?! No! It does not help, It makes the drag higher. Do we need the protection?! Yes, we do!! (at least I know for my self). Now, what to do?! The best is to find compromise between protection needs and performance For those who likes performance flying ( I do ) the full face helmet is the best choice. Which one is the best?! It is very much personal preference. Some people will go for Stinger or any other type of full face, some will go for something else, but, remember that every single change on the leading edge (head is the bigger part) on WS changing the drag as well. For how much, that is another Q. Need to say that more important is the position of the head in performance flying than type of helmet. On relaxing or flocking WS this is really not the issue at all.
  17. That "depression" which is so obvious on Rock Dragon actually happens on every single opening (regardless of the type of canopy, with or without vents). It is happening because of one single reason - at the very early stage of the opening the centre part of the canopy is in stall position, and the full pressurization will begin when canopy starts to move forward. Before that it is very common to see the "depression" of the top surface on the central part of the canopy. The main purpose of the canopy vents (of any kind) is to improve (speed up) slow canopy pressurization at early stage of the opening. What are the benefits of 5 vs. 4 vents?! The MDV system was meticulously designed, thoroughly jump tested and proved in the field through the years. 5 vent system allows for the fastest inflation and pressurization of the canopy available nowadays on the market. Central vent also ensures symmetrical pressurization and helps the pressurization of the central, most critical part of the canopy. Total area of 5 vents on Troll DW MDV is approximately the same as the area of 4 vents on the other canopies, but proper sizing and placing of the vents is of outmost importance on 5 vent system. Compared to other 4 vent equipped canopies on the market, the 5 vent equipped Troll canopies have faster, but not harder openings! Robert Pecnik
  18. Of course it is above. Putting the answer that way: ''slightly above.'' What we have?! Is this hard data?! To get the polar curve for WS is almost mission impossible. (unless we hire NASA) I mention tunnel as well to give the thoughts about what we can get there. What is possible and what is not..... Robert Pecnik
  19. Wingsuit is basically soft or semi rigid airfoil which inflates in first few second of jump/flight. But even if wingsuit looks and flies a lot like an airplane, great deal of things are making wingsuit very different from other rigid flying objects like airplanes, gliders, hanggliders and even parachutes and paragliders. All these objects are of definitive shape and are not changing much during flight. On the other hand, human body is not a rigid object nor can it keep exactly same shape/position for a long period of flight so it is impossible to accurately measure number of things, including the polar curve. There are so many variables which must be taken into account, but can not be accurately measured, like change in lift/drag with change in body/arm/leg position, drag of particular part of wingsuit, inability to maintain proper body position due to tiredness and its influence on GLIDE RATIO, etc. GLIDE RATIO is the basic data we need to see how particular wingsuit flies, not the polar curve, because the GLIDE RATIO is the most important measure of efficiency of particular suit. Of course EVERY pilot will have different result because each pilot flies differently, has different body shape, arm and leg length, weight distribution (centre of gravity) and consequently different position of centre of lift even if using the same type of suit. Additionally, on skydives (jumping from the plane) measuring the GLIDE RATIO is also not really accurate. For example, it is rather complicated to accurately account for momentum provided by the plane and for drift caused by the wind (and very often wind varies in speed and direction for different altitudes, and accurate data for that is almost impossible to get). Wingsuit is very dependant on personal flying skills, and even putting the same suit on identical twins (or triplets or even more) would most likely produce very different results, even though they may have identical body shape and density. Then try to imagine the difference in results if we try to compare measurements taken from, for example, Denny DeVito and Dennis Rodmann, both flying the same type of wingsuit. Testing the wingsuit in wind tunnel is very interesting topic. To find/measure flying characteristics on rigid flying objects (planes, gliders, hanggliders, etc.) is easy. Make the model in 1:1 scale (best but seldom possible) or 1:10 (or any other practical scale, depending on the available working area) and put it into the wind tunnel, fix it on aerodynamic balances and start the software and the fan. In few minutes you'll have most of the data, drag, lift, stability, etc...... To place the human (not fixed object) in the wind tunnel is not that easy. First we have to find wind tunnel with working area big enough to suspend skydiver in. Next problem is how to suspend living human, without interfering with his natural or best flying position. And even if we succeed to do that, we do not have any guarantees that we managed to guess proper (or best) angle of attack for that suit and that very person. Most of the time we will be able only to see the air flow around the wingsuit and use that data to streamline or clean up wingsuit design. But that will work only for that particular person that was in the wing tunnel!!!! Of course, we can make a scale model, but then we have another set of problems. First, who are we going to take as a model and scale him down (DeVito vs. Rodmann issue again). Then, how to make scaling. Use of three dimensional scanner of needed size, due to price, is out of question. Even if we succeed to get hold of one, how to ensure that scanned body position is actual body position maintained during flight, and that this is the optimum body position used for best glide ratio? I discussed possibility of testing the wingsuit in the wind tunnel in order to get reall data, with some people from Faculty for mechanical engineering and conclusion was that, right now, the results would not justify the efforts and resources needed for that project. Robert Pecnik