cobaltdan

chord should be measured from the ribs tail to the point furthest away on the rib. this point is not necessarily at the top skin leading edge. most high performance canopies have the top skin curved over, past the chord slightly (splitting hairs)... sincerely, dan

hi riggerrob, which measurement method do you prefer. perhaps the easiest standardized method is simply the flat cord-wise area. sincerely, dan atair

i was first aware of a problem with x-fires around november of last year. told to me by jyro was that icarus "was aware of problems and tried to implement fixes" and that "they did not think it was serious until lisa died". discussions on potential problem with the x-fire have been flying long before lisa's death. we tested a canopy and the contacted icarus and skydiving magazine. i believe it was in direct response to this that icarus issued their first bulletin several days later. they had no choice as it looks much better coming from them than us. their statement was issued only after the proverbial sh^t hit the fan. "I'm not trying to flame you Dan - but what would Atair do differently than Icarus is doing now if an Atair canopy had a problem? " i would like to believe we could not be in the same boat as i believe icarus and atair practice different ideas on what is required to qualify a canopy for market release. they would perhaps say we are over cautious... atair canopies are extensively tested, and not just edisonian style. spent in the last two years over $300k on development work, including custom designed and built test equipment for measuring canopy opening and flight variables. the test equipment we built is now setting the new standard for top paraglider companies as well as military and aerospace parachute manufacturers. we have developed many new canopies this year. they will not be released for quite a while as it requires a signifigant time to complete all the lab testing, and field testing, we require. our newly released base canopy took two years to qualify. icarus releases new designs/modifications by comparison at a breakneck speed. ie. on the fx canopy, how many of you know there are 29 models? after the 8th model they began selling them to the public, and over the next 2-3 years icarus seamlessly implemented and sold 21 additional models of fx canopies. even if there were no proof of x-fire modifications, it seems that this is standard company practice for icarus. jyro stated "well everybody does it" in response to my comment that it is unethical to seamlessly release modifications like this. my response was "well not atair". what would i do diferently? well that is tough as owning up to mistakes made comes with serious legal and financial reprocussions. i would like to believe that i would have the integrety to do the right thing, but do believe that most people would throw ethics out the window and go for self preservation/damage control mode, ie. cover up, shift blame, protect finances... sincerely, dan

"Unethical would have been telling us nothing while they're doing so or denying that there is a problem at all." where have you been?

understood.. definately when someone is downsizing and trying a new canopy, advice should err on the side of caution. sincerely, dan

i have to dissagree with this post, not because i want to sell cobalts, but because it is simply not correct. if you are considering a sabre, sabre2 or safire, i am confident you may find the cobalt to be a superior choice. contact our office and they will be glad to provide testimonials from instructors ranging from glen bangs (head uspa s&ta), to dennis okeef (head instructor perris valley). sincerely, dan atair ps. (atair sponsores no one with free canopies, not even our test jumpers/swoop team. if you see someone jumping an atair canopy, its because they like it)

frustrating, isn't it... thats why we had a custom autolisp routine written for our cad program. the calculation is done automatically in our modeling program. as far as the tempo, stane measured it at 100, the strong stellar 120 was 110 and the pd 113 was about 113 (kudos)... sincerely, dan ps. btw the cobalts aren't to difficult to measure as they have 3 straight middle cells and a linear taper on the 3 outboard cells.

as i read the release what i get is that 'good' x-fires with spectra will become 'bad' xfires as the lines wear and that the canopy is so sensitive that the normal dimensional shift on spectra line could make the canopy unstable. i have several issues with this: 1-i do not favor vectran. reason being that most jumpers do not carefully, routinely inspect their lines. nor do they accurately keep track of the # of jumps on those lines and religiously change them. on a soft opening canopy, there is the real possibility of when lines break, it will not be on opening but on a radical turn. if this if your final hook or anything below cutaway altitude you are in serious trouble ! 2-canopies are flexible membrane structures. in addition to the lines changing specs with use, so does the fabric and tapes. the airfoil and planform design and other design variables can not be 'borderline' safe. they must safely allow for variences in sewing, line, fabric, and tape tensions. 3-least of my concerns would be economical...ie. who is going to pay for the reline. as well as the now higher cost of maintainence, ie. vectran lines will probably have to be religiously replaced twice as often as spectra. 4-icarus stated that the canopies are out of tollerence, but have not publically said word one as to what tollerences are off. every construction specification on a canopy can be measured. if this is true then why has icarus not stated exactly what has been constructed out of spec, what the factory specified dimensions are, and what is the acceptable tollerence on those specifications. typical canopy construction involves the cutting of fabric pannels on a hot knife or laser plotter from a computer cad file. this is dead accurate, additionally match marks are cut or marked in ink during this plotting process. when a seamstress sews the canopy together the match marks are overlaid. if a canopy was constructred out of tollerence. either the computer files were incorrect and therefore the fabric pannels cut out reflecting this. (as the computer files do not magically change, they are what was designed, i would call this a design flaw), or the cutting machine is messed up and one axis is out of scale from the other (doubtful, this is a mechanical function, ie. x steps of the motor creates x" linear movement, this is preset and never changes), or it was sewn incorectly. typical problems in sewing are mainly being sloppy ie. not aligning the match marks or not keeping even tension on seams. i believe precision uses visible ink for the match marks (atair uses small holes). you can not state something is out of tollerance without specifing, what, its specified dimension and acceptable tollerence. until that this statement is simply BS. sincerely, dan

all of the major manufacturers use computer progams to generate our models and patterns. it is easy to calculate the exact area of the canopy: ie. click the icon. some canopies have false square footages labeled, i believe for sales reasons. ie. a tempo 120 is actually more like a 100. people buy them because the pack volume is so small and they are cheaper. well this is because they are smaller than you think. if they were labeled as a 100 many people would probably not buy them. a docile elliptical canopy can be far more efficient that the equavilent skill level square, thus requiring a smaller canopy/ slightly higher loading. because of the fact that many jumpers, novices especially are uneducated it is a hard sell to put them on a proper size of high efficiency canopy for them, if it is smaller than the old technology square they learned on. this fact i believe influences some manufacturers to mis label the square footage on their canopies. atair opted not to do this. all atair canopies are labeled exact. instead of labeling a 160 a 170 we try to educate on the differences of canopy models, loading and efficiencies....etc.. sincerely, dan atair

drop me an call or email with your address and i will send you a line trim chart for your canopy. you can measure your lines quite easily: nail the beginning of a tape measure to your floor. slip over the nail your link connectors. pull taught one set of lines at a time (one left and the same line right). use equal tension every time you measure. match up lines to tape measure and record the dimension. work through every line. then subtract the offset created by the link and compare with the manufacturers supplied chart. sincerely, dan atair

we are in the process of building a vertical tunnel in ny contact me off list if you need more information. sincerely, dan atair www.extremefly.com

food for thought. precision copies icarus canopies minus crossfire. this was long before any public issues on the crossfire. why didn't george galloway copy the crossfire too. instead he licensed a competing design from germany.... icarus states only american (precision made) canopies are potentially effected....i do not believe this to be true (as i have an effected crossfire that is from europe). but, this does serve to make precision (effectively an ex icarus partner and now competitor) look quite bad. icarus states it is a line trim problem, not a design defect with the canopy. if the problem is simply line trim why has the line specification sheet not been posted. anyone with a tape measure can check line trim. for those of you not familiar with how line trim is checked it is simply measuring each line and comparing the length to that listed on a chart. if this is a tollerence issue, why has icarus not stated the applicable specifications with required tollerences for anyone or anyrigger to measure. why would an s&ta have to certify their product to be safe, most especially without knowing the exactly what to measure. what does being familiar with someones piloting skills have anything to do with a tollerence issue of a canopy. daniel preston atair aerodynamics

hi zennie, don't be leary of the cobalt. if you are comfortable jumping a sabre2 you will be equally comfortable with the cobalt. at the loading you are jumping the cobalt is an excellent begineer canopy. demo it side by side with your other choices, very good chance you will like it better. when you see a high experience jumper under a cobalt surf distance, it is under a signifigantly higher loading. bridgit liss has competed in several pro-swoop competitions this year under a spectre. a canopy that no one would consider high performance, the difference between the begineer jumped spectre and hers....skill & wing loading. the cobalt is not a faster canopy than your other choices to demo. btw given that you are used to a sabre, my feeling is that you will not like the spectre or diablo. you simply will not get the same glide. the sabre 2 will have a better glide than your sabre and the cobalt even higher. have fun. dan atair

as the main sponsor of bridge day this year, atair is sad to announce that bridge day has been cancelled for reasons of security. ....cya

a note on your 6 g estimate. this is not a worst case assumption.... i have recorded a force vs time graph with the peak force spike exceeding 50 g's on a sabre 135 canopy.... a quick 6 g's spike would not be very noticable as a hard opening. it depends on the width of the spike. remember to the jumper it is all about force vs time. ie how long that force is applied to your body. a hard opening canopy will typically spike you in the 6-11g range and a dangerously hard canopy can spike over that. to your cable a short high spike may kink it whereas a longer more moderate spike may not. another point to consider. the 3 ring system does not have fixed fulcrums, it is a flexible structure and the pivot points can move considerably. therefore its mecanical advantage can vary, in particular if it is twisted. sincerely, dan atair

hi marcin, the impulse, alpha and space are all names for the same canopy. the cobalt is based our same proven planform and airfoil with the following primary difference: top skin is constructed from 18 panels instead of 9. this creates a cleaner airfoil and enables us to slightly rehape the panels to induce a stress pattern in the top skin, thus reducing distortion and increasing efficiency. this is very noticable at high wingloadings, less at low loadings. sincerely, dan atair aerodynamics www.extremefly.com

as you assume the brunt of the force will be taken up on one side, but the distribution between front and rear makes no difference as the sum will be applied to the ring. the issue is not steady state force on your cable but the peak force. the peak force applied can be enough to kink the cable into the relatively wide gromet. once that is done it forms a 'detent mechanism' which has a huge mecanical advantage. a pull force on a non kinked cable of 25# can become 10 times higher with a kink. sincerely, dan atair

i have been under 2 different airlocked canopies and induced a mal where the inboard turning side folded between the b& c lines. the mal is unrecoverable. interesting though is if you cut holes in the canopy (i put 1/2" holes in the top skin near the tail) the canopy will depresurize and self correxct the mal, if the vents are slightly larger the mal can not be induced in the first place. i do not believe airlocks offer any bennifit. they sound good in laymans terms but scientifically they have not stood and there has been 2 decades of testing in the paragliding industry. btw. does not mean that an airlocked canopy can not have nice flight characteristics sincerely, dan atair

i am confident you will find the cobalt to be a superior choice to a stilletto or vengence. please check us out: www.extremefly.com sincerely, dan atair

i do believe in the right equipment for every job. if you are into a specialized dicipline as wingsuit flying, you should have specialized equipment for the task. ie, larger pilot/longer bridal/track deployable container. body position is also very important. i have heard many different techniques for deployment body position on wing suits. what works for me was taught to me by robert (birdman designer) and stane (atair founder) while learning to fly my skyflyer in slovenia: track like a bat out of hell, shoulders and elbows rolled foward, forearms almost parallel to your body, palms facing out away from your body, no arch, knees almost straight, toes dug in, head looking down not foward. in this position you will travel very fast foward and create the slowest possible vertical speed. when it is time to dump (for me that is a high 4-5k) i first apply the brakes by bending my knees, momentarily bleed off a little excess foward speed and then transition immediately back to the full foward track position, then close all wings and throw the pilot. do not deploy in an arch. when you close your wings to deploy your body should not change position. this is tricky and takes some practice and awareness. by dumping in a proper full track the pilot is deployed into clean air. when you arch to slow down, even if you are still tracking foward, you are effectively in a stall, your pilot goes into separated turbulent flow with unpredictable results. be safe, dan atair

we used a load link sensor connected to a digital data acquisition recorder. tension in increments of ~1.56# is recorded at a rate of 200 times per second. a fish scale will not give you a force vs. time graph or even peak force for that matter. from memory our 22" were giving us 50-60# steady state. posting the graph data it is on our list of things to do for our web programmer. -dan atair

a bunch of posts here imply that stupid shit doesn't count.. well, EVERYBODY does something stupid once in a while. it counts ! if you do not think so you are trying hard to ralationalize issues to yourself.. remember to the person that did the "stupid shit", their window of perception at the moment was such that it was either an instinctual reaction, non reaction or just didn't seem stupid at the time. in a sport where a dumb mistake can have serious repercussions, my thoughts are to try not to ever get too comfortable. i believe after you have reached a comfortable point in the learning curve of this sport, people have a tendancy to relax. they simply perform and fly the same way jump after jump. their window of perception for diagnosing and reacting to new situations is substantially narrowed. this is an accident waiting to happen. sincerely, dan atair

hi mike, when i saw you post i had a bunch of stuff to reply, but db pretty much covered it ! a while back we were noticing some iniatial high spike opening force during some tests (we have a datalogger connected to 4 riser load links as well as helmet mounted accelerometers). anyway we traced the spike to the pilot chute. we wound up recording the force vs time curves for 28", 24",22",& 20" pilots that were custom made for us by jim cazer. we did this by throwing them from the back our f150 at 70mph using the datalogger and 1 load link. we then extrapolated the data out to 140 mph. we recommend 22" for cobalts 135 and smaller, for the 150-170 we typically recommend 24" both zero p collapsable. sincerely, dan atair aerodynamics www.extremefly.com

my prefference is for brass with soft links... dan

design study attached for havok.... boneheads kick ass :) dan