cobaltdan

"You know you really hit on my biggest pet peeves. I don't know how many times I've been told "you need to be hooking that canopy", yet none of them can tell me why I should be hooking it other than it is an elliptical canopy and ellipticals need to be hooked. Which is bull shit, if you can't land a canopy strait in you have no business jumping it. " Skykat, i used to say i would never perform hook turns. at a low number of jumps i had already seen too many people get broken doing hooks. i had much the same feeling as you expressed in your post above ..... then i read an article pointing out that there are 2 kinds of people that will get killed doing a hook. first the experienced hot shot pushing the limits, and the second the conservative pilot that says i will never do a hook turn ! the reason is that sooner or later you absolutely will be in a less than planed situation where you will need to perform a low turn to land. such a situation is >not< the time to learn how. that article changed the way i looked at canopy flying. i firmly believe in learning the complete flight envelope of your canopy during planed practice. you need to be fully familiar and current on all aspects: flat turns, diving turns, landings: up/down/cross and with all possible approaches: straight/90/180 begineers should practice everything up high. hooks included. intermediates can practice hooks by offseting them from the ground, i.e. placing your turn to plane out 50' too high. with higher experience that offset can be reduced if desired. but in the event of having to perform a low turn to land, such practice will have been invaluable. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

the space, alpha and impulse are all the exact same canopy. they were designed and manufactured by atair. the space and alpha were private lables for skydepot who at the time was a distributor for us. the space was marketed as a begineers canopy to be used at loadings in the 1-1.4 range. the alpha was marketed as a high performance swoopers canopy, to be used at higher wing loadings up to 2.4. the impulse is the european name for the alpha/space. the cobalt is based on the same airfoil and planform but has distint differences. first the top skin is made form 18 panels, this allows us to shape them to impose a stress pattern on the top skin. this effectively lowers the spanwise distortion making for a canopy that is more efficient. additionally the crossporting is different providing for higher speed safe deployments. the competition cobalt is based on the cobalt but with a spanwise braced nose, formed nose, different crossporting, addition of bottom skin inlet area, and a-lines... sincerely, dan atair aerodynamics www.extremefly.com Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

hey newbie, it is best not to use your rear risers: one it can make many canopies open faster and consequently harder and two you can deflect one more than the other inducing a turn or twist. best procedure is simply to let your canopy finish deploying, to inflate closed endcells simply unstow brake lines, allow canopy a few seconds of foward flight to gain speed and perform a slow flare. pumping toggles is usually ineffective. a slow flare is much better. take several seconds to flare and you will feel your self go from pendulmed slightly behing the canopy (full flight) to pendulmed just under (level flight, swoop), to pendulmed slightly infront of the canopy, it is at this point that your end cells will inflate. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

hey phree, "out swoop stillettos, cobalts, crossfires, and crossbraced....." you have got to be kidding.... bridget is a decent swooper but was severly limited by her past choice of a spectra for competition. the only reason she even placed was because of receiving the highest style points in the comp when she jumped topless and chowed big time... spectre are nice canopies but they are not out swooping anything except student canopies, tri's and jalbert's. btw a spectre and stilletto have identical airfoils, just different planforms. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

hi aggie, not sure you analogy quite works. your 707 has drastically higher wingloading and speed than the 172. the difference is weight from a boat canopy to a pocket rocket is only a few pounds. this can be discounted, inertia is mass times your speed. lightly loaded canopies have no speed. lift, skin tension, cell pressure, etc... are all proportional to speed. tandems should not be much better than a lightly loaded sport in turbulence, yes, they have a large wingspan but primarialy i would say the difference in turbulence from a lightly loaded sport canopy, is probably the diference between a highly experienced pilot on the tandem and a not so experienced pilot on the lightly loaded sport canopy. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

the vx has aramid lines. the burn marks were not burn marks as rob pointed out. on a slider first you do not necessarily want to reduce friction. assuming you did, a spectra/vectran to bearing plastic given the operating pressures and speeds would not provide any lower friction than ss. on our guided parachute systems there was a situation where i wanted to lower friction of a guide and a line. the solution was not plastic but to impregnate the line with moly. disulfide a high pressure dry film lubricant. if you want to play arround with it make sure you impregnate the lines with an alcohol based suspension not petroleum. btw its black and messy... sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

hey quade, i was referring to "minor" turbulence whereby no accident resulted. definately a faster canopy can inflict more injury when crashing than a slower canopy, but also there is a point that most canopy collapses are lightly loaded canopies (many times in partial brakes) that are strongly effected by turbulence that higher wingloaded canopies dont even feel. i think roq summed up everything pretty well. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

yes, most high performance canopies are far less effected by minor turbulence than lightly loaded squares. primarily because they are faster and more efficient. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

we have recorded over 5 g's in a spiral at very high wingoads. on your lightly loaded sabre i would guess around 2 g's. black out from g force is basically caused by lack of oxygen. blood pressure increases from being forced to one side of the body and you run into issues with oxygen being able to perfuse into your body against the higher pressure. i believe lower oxygen pressue at altitude make this effect worse. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

definately...before you get on that plane ask yourself would you take a downwind landing? if you are not comfortable performing a downwind landing, you should not be jumping in the current winds or on your current choice of canopy. downwind landings should be practiced ! (let every one in the plane know your pattern) you will sustain far more injury from a botched low turn into the wind than a botched downwind landing ! we all know hot to plf...and if you had practiced, it wouldn't be a plf. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

i would shy away from recommending strong equipment to this potential student as i believe strong tandem reserves are not rated for the higher terminal speeds involved in a non drogue freefall. in the event of not being able to deploy the drogue, proceedure would dictate deploying the reserve. at non drogue freefall terminal speeds you can significanly exceed the capabilities of the strong reserve and damage it on deployment. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

hi jerm, just back from a week of test drops and trying to catch up and overcome some computer problems... anyway, i think the confusion is about definitions: collapse: when a canopy is no longer is in flight supporting the jumper. in turbulence locking air in a cell changes how the canopy collapses but it still collapses. again fly an airlock because you like how it flies, do not fly one because you believe it will save you over an open cell canopy in turbulence, it will not. be safe. dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

at 300# drogue fall is required in freefall to avoid too high a terminal speed. equipment wise there is no problem a tandem rig i.e. from rws with a 350 cobalt and reserve. problem is perhaps teaching a newbie on a drogue fall rig. this is done in the military but i can see why with all the added things that could go wrong a sport operation would definately shy away. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

we have not found sharpies to damage spectra or vectran and have used them in production since 1992. sincerely, dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

i am just back froma week of drop tests and trying to catch up. a think the minor confusion is about definitions. collapse: when a canopy is no longer in flight supporting the jumper. airlock canopies can collapse in turbulence, same as a non airlocked canopy. keeping the air in does not prevent this. sincerely, dan Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

i recommend 2 percocets and a cobalt i know how you feel. i began designing canopies as a result of breaking my c6 on a sabre 135 slam. i was in severe pain and visiting a chiropracter turned out to be a mistake. see a good orthopedic doctor get a proper check up then see a chiro. if warranted. feel better. sincerely, dan atair www.extremefly.com Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

tom, they were not pc oscillation tests, they were tests of force vs time when deploying variuos size pilots. as a result oif doing this test we got the chance to watch pilots in flight. all tested pilots zp or f111 tended to slightly orbit but not oscillate unstably. as far as sub terminal base jumps: huge difference to skydiving: first large f111 pilots are less stable than small z-ps from what i have seen, base pilots are f111 and significantly larger than skydiving pilots. next you will never have such a slow speed deployment in skydiving (remember you are jumping from a moving airplane). if you do happen to be in a very slow moving plane, it will only take you several seconds to get up to terminal, and if you do not have several seconds to get to terminal you have no business deploying your main, that is what your reserve is for. side note: for safety sake all of us drill certain reactions into our brains, i.e. not s-s-s-s = ching-ching. but one that many of us do not think about making an automatic reaction is altitude vs handle: i.e. sh^t i'm low: pull.....but which handle did you pull? if you are below your hard deck : pull reserve. sincerely, dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

phree: actually, x bracing does increase the rigidity of a parafoil. one technique of many. increased rigidity translates to less distortion during manuevers. sincerely, dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

hi mike, not trying to nit pick: -airlocks do not improve your airfoil shape, if you look at an airlocked canopy you will see that it exhibits the same spanwise distortion as an equivalent design standard canopy. i.e. samuri vs stilletto. simply look at advertisement pictures of both canopies, you will notice that the airlocked canopy has non loaded ribs that float up higher than the loaded ribs forming a zig zag leading edge tape, just as bad as the stilletto. additionally airlock canopies exhibit an increased spanwise distortion when in brakes. (note as an airlock is a piece of fabric attached to the nose it could be designed to provide additional support to add rigidity and decrease distortion, but no airlock designs to date do so) -unlikely to collapse. not true. locking air in your canopy will not stop a canopy from collapsing in turbulence. airlocked canopies can and do collapse. fly one because you like its flight capabilities, do not fly one because you have a false sense of security that it will save your butt in conditions that another canopy wouldn't. -cant wrap: airlocked canopies in a hard bump will fold between the b-c lines initiating an unrecoverable spin. -tollerates higher wing loadings: not true, atair 9 cell canopies followed by icarus tricell canopies have demonstrated the highest wingloading capabilities. current marketed airlock designs are rated for much lower wing loadings and as such not offered in very small sizes. -longer surfs: not true. current stats from a year of competition puts the velocity at #1, competition cobalt #2, with icarus and precision tricells following. no airlocks i believe even placed in a full year of the para performance games. -bigger pack volume: a bit, not enough to put you up a size. -more expensive: a bit, in line with other high performance 9 cells. -pain to collapse on landing agree with you there. sincerely, dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

thanks for the feedback. i will check with the silk screen company that makes them for us. sincerely, dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

i have to completely dissagree with pisa here. the statement that z-p pilots are unstable because air can not pass through them and spills over the lip is bs. prove it to yourself attach a z-p pilot to the back of your pickup and go for a drive.... we did.. on sizes from 18" -28" to record bridal force vs. time when letting go of your pilot. anyway, a 32" is too big, the 24 is not. you will not have a problem with the 24 on hop and pops . sincerely, dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

the logo is a silkscreen print. strange...did the "c" peal off or just fade? -dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

a 24" zerop kill line pilot is perfect for a 150 hornet. set your pilot on the ground and flick it so that it catches air and drifts to the ground. do that several times if it catches air and falls without any obvious defects, i.e. always spilling air to one side. the twists were definately not caused by your pilot. sincerely, dan atair Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

hi kelly, i just wote a great reply but my computer crashed before it went up....quick recap is below. there was a long wait for the demo cc85 and i'm pretty sure stacy sent you my personal canopy (silver one). if so yes the toggles are set short, simply my personal prefference. if you stalled the canopy it was simply bad technique on your part. i am not trying to slam you or anything, but if you can not figure out the control range and stall point of a canopy long before you are on landing approach, you should reconsider jumping high wingloaded sub 100's. hey i have stalled canopies on landing too, but i didn't blame the canopy, it was my own fault for being complacent and trying to figure out the control range on final instead of at altitude. speed: cobalts are slightly slower, but they generate more lift. you need to load slightly heavier of you want increased speed over your fx. cc will swoop farther than you fx definitely ! the recovery arc of the cc is also very different from the fx. it is positive meaning does not require any toggle input. overall, it just sounds like you tried to fly the cc like an fx, without any thought to how this different design canopy needs to be flown. different canopy designs have different flight envelopes, as a high performance canopy pilot you need to know how to evaluate and learn each new canopy you try. if you would like to give it a go again with an open mind i can send you a cc85 or cc75 (with deeper toggles), but i would want to discuss flying technique with you first. i.e. you say you do not like carves, but a correct carve will generate more speed on a cc than any other method, etc... sincerely, dan atair www.extremefly.com Daniel Preston atairaerodynamics.com (sport) atairaerospace.com (military)

alban (skyray designer) and i have been collaborating for several months on designing a powered version. 40# of thrust is required for level flight and 60# for climbing. mini turbines are the obvious choice but r/c versions are not suitable due to several issues, and suitable military pyro starting units are cost prohibitive. i have chosen a 5hp, alcohol powered, variable pitch 6" ducted fan producing 15# thrust. four will be used. ultimate goal is military applications, near goal is to generate capital for our respective companies through an english chanel crossing for the 100 year anniverasry of powered flight. sincerely, dan atair www.extremefly.com