Submit Article

Skydiving News and Articles

Select A Category

Pick a Category

Top Ten Misconceptions About Zero-P Canopies

A while back, I overheard a bunch of people discussing their lative merits of different types of canopies and materials for low-time jumpers. I heard some interesting misconceptions about what's dangerous and what's not, what works and what doesn't. In the interest of getting some discussion going, I figured I'd-list my top ten misconceptions about Zp canopies:
1. Zero-p canopies are dangerous.
Zp canopies have gotten a bad reputation over the years, since most hp canopies are made of Zp fabric. However, this does not mean that hp fabric itself is dangerous - it just allows smaller canopies to land well, and so is often used for smaller, high performance canopies. A large 9 cell Zp canopy is just as safe a sits same-size F111 counterpart.
In fact, it is often safer. Zp fabric keeps air from escaping though the top and bottom skins of the canopy, and thus allows better canopy pressurization at a given airspeed. This helps prevent canopy collapse in bumpy winds. In addition, the Zp fabric allows the airfoil to be a bit more efficient, and thus allows you to slow down a little more before landing. During a landing in a bad area (a power station, for example) that slower speed can be a life saver.
2. Zero-p canopies are harder to land than F111 canopies.
Not at all. In fact, the opposite is often true. Zp canopies have more lift during the flare, and that extra lift can be used to slow yourself to walking speed before touching down. F111 canopies, especially old ones, often can't do that any more -they become so porous that they stall before slowing you down enough. Often, you will see people with older F111 canopies doing all sorts of tricks to get good landings - front rise ring, taking wraps on the brake lines, and turning low. Generally, such maneuvers are not required with Zp canopies.
This year I watched maybe 200 landings at bridge day. Conditions were not great - zero wind and an uphill landing. The people who got the best landings were the people with fairly new(i.e. not porous) F111 canopies and the people with Zp (Triathlons, Sabers, even a Stiletto or two). The people with the ragged old Cruise lites and Pursuits were slamming in hard. The canopies simply did not have enough lift left to slow down the jumper before landing.
3. F111 canopies are a good choice for a first canopy.
Well, yes and no. A good, fairly new F111 canopy, loaded correctly, is indeed a good first canopy. However, you have two things against you:
Few people sell good, low-time F111 canopies anymore. Most have 500-1000 jumps on them, and at that age, they become difficult to land. A larger canopy will not be affected by this as much as a smaller canopy, so size matters. A pd230 may still land you well after 1000 jumps, since its forward speed is low to begin with. A PD150 with 1000 jumps will be very hard to land without injury for most jumpers.
  It's hard to resell F111 canopies, for the very reason mentioned above. They are generally retired after about 500-1500 jumps, do you're paying about $1 per jump for them. Zp lasts much longer - you can easily get 2000 jumps out of a Sabre 150 with an occasional line replacement. This ends up costing you around $.60 a jump. 4. Zero-p canopies open really hard.
This rumor came about mainly because of the performance of the Sabre and the Monarch, two popular Zp 9-cells. It is no longer true. The Sabre was tamed by a larger slider, and mods exist for the Monarch. Newer Zp canopies, like the Triathlon, open quite reliably and comfortably. Some new Zp canopies, like the Stiletto, Spectre and Jedi, are designed to snivel for a longtime, and give extremely soft openings.
This was a boon for cameramen, who need soft openings due to all the weight on their heads.
Of course, there's a trade off between too little snivel and too much. But there are Zp canopies available that open at nearly any rate, from rapid to very slow. Packing is an important part of that scale, and between canopy selection and packing technique there should be a wide range of openings to choose from.
5. You have to get a smaller canopy to get better landings.
Not true. Many people start out on old F111 canopies, and simply assume that to get nice, soft, swooping landings like the pros, they need a small canopy like the pros. The truth is that nearly any Zp canopy will land you well, if you fly it correctly.The technique you use depends on the loading, as listed below:
6. You need to get a smaller canopy to go faster.
While it's generally true that smaller canopies go faster,there are many other options to increase your speed and turn rate without taking away wing area. Wing area is all you have keeping you in the air, and taking it away decreases the canopy's "forgiveness", or tolerance for mistakes. Some ideas for increasing speed/maneuverability without sacrificing area:
Canopy choice. The Silhouette, for example, is designed to be a faster large canopy. A 170 should give you nearly the same forward speed as a Sabre 150, with the extra forgiveness that the larger size entails.
  Pilot chute. The single best thing you can do for your medium / high performance canopy is to get a collapsible pc. It will do wonders for your glide, forward speed, and flare. I highly recommend this as a first step, before you get rid of that old, doggy canopy. Even older F111's can benefit from this.
  Slider. Figure out how to stow your slider somewhere. There are many different types of collapsible sliders, and they affect performance two ways - by reducing drag, and by allowing the risers to spread out more. Avoid stowing it on your jumpsuit, though - this can prevent a cutaway if you have a problem later, and has led to a few serious injuries.
  Riser tricks. Mini-risers reduce drag a bit, but not a whole lot. Separate riser-keeper rear risers allow the toggles a bit more freedom, and distort the canopy a bit less when you flare, allowing a little more flare power. Front-riser handles allow you to easily add front riser, a good way to increase your speed when trying to buck a headwind (for example.) 7. You should never, ever turn near the ground.
This is a good rule of thumb for your first few jumps.However, there are times when turning near the ground is necessary, and all jumpers should know how to do this safely. Basically there are two ways to turn low - the braked turn and the flare-turn. Practice these! Both allow radical turns without a resulting dive towards the ground. Many jumpers have been killed when they found themselves flying downwind or towards an obstacle on final, and tried to turn without using these tricks.Depending on the canopy, you can safely make a 180 degree turn as low as 50 feet - if you've gotten instruction on how to do it and practiced it up high.
8. Skydive Chicago puts first-time jumpers on tiny Sabres.
Not quite, but close. They put first-time jumpers on Mantas(or have them do tandems) for the first few jumps, then transition them to hp canopies. And interestingly, there have not been more injuries as a result. I think this is because many new jumpers learn bad habits on Mantas, and these bad habits are difficult to unlearn. At Skydive Chicago, they transition early on, and get good instruction on how to fly the newer hp canopies.
This is a good model for transitioning ourselves. Whenever you're going to make a significant canopy transition (i.e.smaller, square to elliptical, etc.) get instruction! It costs little to badger a more experienced jumper or instructor into watching you land a few times, and the advice you get can be invaluable later.
9. 7 cell canopies are dogs.
Not any more! The Triathlon and the Spectre are both high performance Zp canopies, and are good choices for jumpers buying their first Zp canopy. The big difference between 7 and 9 cell canopies is aspect ratio - which is just the relationship between wingspan and front to back size. 7 cells have ar's around 2.5 to1, and 9 cells are around 3 to 1. Generally, a higher ar has a better glide ratio, but that's about the only hard-and-fast difference. Zp 7-cells can go as fast, land as well, and plane out as far as their 9-cell counterparts, if they are loaded correctly. They are a bit more forgiving at similar loadings, and are thus a really good choice for a first Zp canopy.
10. It's really hard to pack Zp fabric when it's new.
Sometimes this is true, but not always. "South African" fabric, such as the material they use in the Triathlon, is pretty easy to pack from day one. It doesn't seem to last quite as long as the more slippery PD material, though.Some canopies, like the Silhouette and the Turbo-z, mix F111 and Zp material to make a canopy that flies well and is still easy to pack.
But even a brand new Sabre is manageable, if you work at it.The psycho-pack is a good way to control an unruly canopy, and there's at least one gadget out on the market that helps you pack slippery canopies.
Copyright ©1997 Billvon Novak, Safety and Training Advisor

By admin, in Gear,

Buying your first set of Kit

Mk 1 PC with sleeve in lightweight
2 Pin Pack, Complete with matching reserve container.
Lightweight I24 - unused. A bargain at only £250!
Ideal First Kit! How many ads on the notice board at your parachute centre start or finish with these words?
My immediate reaction is to want to tear down the ad, because the chances are it isn't. Take a closer look at the kit and it will be something that was 'hot' fifteen years ago, has not been in production for at least ten years, yet comes with the statement 'only 250 jumps'. The seller has to try to sell it to an unsuspecting novice, because no-one else would touch it. So, buyer beware! That is not to say that it is necessarily unsafe, merely it is not ideal first kit, unless your only consideration has to be cost.
Advice should easily be on hand at any drop zone in the form of instructors and riggers (other than one who is trying to sell the kit!). Never buy your first set of gear without plenty of advice from someone whom you would trust. Always ensure it has been thoroughly checked beforehand. Apart from the serviceability of the gear there are many things you will need to take into account:

experience level
skydiving interests
where and how much you will be jumping
re-sale value
your wallet! Let us look at some of these in greater detail and answer a few common questions:
Experience level, age and weight
If you have just achieved category 8, whether on the category system or through AFF, you will probably have between 20 and 40 jumps, possibly all on squares or mainly on rounds. If, like most people you have limited opportunity to hire equipment you will now need to buy something fairly soon. New may well be out of the question, because of the waiting time involved, the cost and the fact that your needs will change rapidly in the next few hundred jumps. There is a lot of second hand equipment about so don't be rushed into buying the first thing you see.
All canopies will state an all-up weight limit for the equipment. This is to include yourself (with clothes), your rig and lead, if used. Many experienced (and some lesser so) jumpers use equipment for which they are overweight but swear by it because of the added performance they gain from it. This is not something to be recommended - the extra performance is in fact an increase in speed, both horizontal and vertical, which an inexperienced jumper is advised to avoid. You need to decide not just whether you can cope in 15mph winds on your big, familiar DZ, but also in nil winds, landing off the airfield in a small area.
When buying your first equipment, it is not a bad idea to go one size up rather than being on or too close to the limit. Don't pay too much regard to the cool and groovies who will tell you how boring you will soon find it. Compared with an Aeroconical or a Manta it will be all the fun you need for a while and it will keep you safe for the first season or two.
Your skydiving interests
What do you want your skydiving equipment to do, other than the obvious decent opening and landing that we all desire?
If you are interested in accuracy or CF you will need a canopy which is suitable for those disciplines. For either you are likely to need a larger, steady 7-cell. More performance can be gained from a higher aspect ratio (more rectangular than square) 9-cell. If you are not too bothered just yet, then either a 7-cell or 9-cell would be fine. There are more and more elliptical, ultra high performance canopies around . These are not intended for the novice and if you were to buy one there are not many CCI's who would let you jump it! 9-cells do usually give more performance (both in the air and for landing), they will tend to be faster but with a greater range of control. These days you can buy a safe canopy which will still give you plenty of forward speed, a good flare and lots of fun. Many canopies are zero porosity (ZP). They take a little getting used to when packing, but they will retain their performance for longer. As long as it is a sensible size for you and not an elliptical, a ZP canopy can be perfectly acceptable as a first canopy.
Do I need a round or a square reserve?
The answer is, if you can afford it get a square. These days it is possible to get decent equipment with a square reserve from £500 to £600 upwards. Consider when the wind is 20 knots on the ground, maybe 30 knots at 2,000ft, whether you would be happy underneath a round. It is not much fun to have to stand yourself down through lack of confidence in your equipment. Also, what is the standard of spotting like - not just on your home DZ, but when you go abroad to boogies? How many hazards are there around? How much overshoot? The only reason for buying a round reserve nowadays has to be because it is very cheap. If you do decide to go for the cheaper option but have never jumped a round, make sure you get briefed on it by an instructor.
Whatever shape your reserve is, ensure you are within its weight limit!
What type of container?
This is really down to personal preference or availability if buying second hand. There are many types on the market these days. The most important thing is to make sure the harness is a good fit and comfortable, with all handles located in a sensible position. The main choice will be whether to have one or two reserve pins. Generally speaking, one pin rather than two will allow for an easier reserve pull. The maximum allowable is 22lbs, check on the repack paperwork how much it was. With a 'Pop Top' reserve (as on a Teardrop for example) the reserve pin(s) are against your back, so are very well protected in the aeroplane. But all modern equipment has covers that do the job. On some older rigs neither the main nor reserve pins are as well protected. This is something to be aware of when sitting down in and exiting the aircraft.
What sort of deployment system is best?
Until you are D-licence (category 10 and 200 jumps) you are not allowed to jump a pullout in the UK. This means ripcord or throwaway. Realistically, no-one jumps a ripcord after clearing student status, so you will need a throwaway deployment. But you still have a choice of where to put the pilot chute; on the leg strap or on the bottom of the container (BOC). Either is fine. If you are buying a second hand rig with one of these, you might as well leave it as it is. If your rig needs converting from pullout, you need to decide which to go for.
These days increasingly the choice is to have a BOC. There are many good reasons. It will always be in the same place, whereas a leg strap can loosen or shift about. There is no (or very little) velcro to maintain. There is virtually no exposed bridle - relevant if you are doing high speed jumping such as free-flying. If you are having it converted there is no velcro to be sewn on the container, so it should be a little cheaper.
The advantage of a leg strap throwaway is that it can be seen. Admittedly most people don't look for it but, one day when you are having difficulties, it may just save a second (200ft) if you can see a handle.
Do I need an AAD or RSL?
Once you are category 8, it is no longer a BPA requirement to have either. (If you jump at a military centre, the cut-off is category 10, so you have no choice until then.) It is only since the introduction of the Cypres that it has been common for anyone but a student to jump with an AAD. This was one of the reasons for designing the Cypres. It is an excellent piece of equipment and if you can afford it, get one. Quite simply there can be virtually no argument against it. If you are still in freefall at Cypres activation height (750ft), you deserve and need it to fire.
There is more debate about the pros and cons of an RSL. Its function is to operate the reserve as you cut away. The disadvantage is that you may well be unstable immediately after a cutaway and hence for the reserve deployment. This is more likely for an extremely high performance canopy, which you are hopefully not jumping. It is more of a problem if you wear a camera on your head, this is not possible until you are D-licence. On balance, for a relatively inexperienced jumper with a relatively docile canopy, an RSL is a good idea.
With both of the above, when you are no longer a student, you need to take more responsibility for yourself, so deciding how many safety features to have on your equipment is your decision.
So why shouldn't I buy that 'Chaser / Pegasus / Preserve IV for £550 ono'? Although 'old' does not always mean 'knackered', the older a piece of equipment is, the more likely it is to be getting worn out. It would need a very thorough inspection of the harness and container - the stitching may be becoming unsafe. The webbing and risers may have spent ten years rubbing against velcro. The main canopy probably has hundreds if not thousands of jumps. It will have possibly lost most of its porosity, giving harder openings and landings. It is coming to the end of its life. Unless it is very cheap and you really cannot afford anything else, I would not recommend it.
In summary
Most equipment that is in good condition, with a square reserve and a main in the general range of 170 to 220 square feet will still be worth relatively the same in a year or two. You can buy it now, use it for a couple of hundred jumps and then resell it to the next generation of category 8 students. In the mean time you can improve your ability under canopy, try some other models and save up for new gear.
Have a good look at the equipment that is around, compare prices and get advice!
Cornelia Waymouth
Illustrations Danny Crossman
Skydive - The Mag

Republished with permission

By admin, in Gear,

How To Select A Parachute Container System

The harness/container assembly is your safety system. Any canopy, round or square, can be plugged into the main or reserve container/attachment, and be persuaded to open. The container system controls the deployment of those canopies. The harness secures you to those canopies. There have been a lot of dissertations on parachute canopies (how to select, fly, repair, etc…). Little has been published about the harness and container system, because, while seemingly simple, they are infinitely complex. The sheer number of the different emergency scenarios while skydiving is astronomical (i.e., low speed, high speed, total, partial, two canopies out, and so on). Your harness and container system must answer these challenges; it must answer them by prioritizing procedures in the order of the frequency of occurrence. Your job is to understand those options and make an intelligent selection. The purpose of this document is to help you understand the individual features you should consider while making this decision.
The TSO is the minimum safety & testing requirement. TSO standards have changed over the years; so the present day TSO may be measuring one quality adequately but not another. There is a difference between a Performance Standard and a Structural Standard. A test to a “Performance Standard” is fine for a functional test. However, testing structural integrity is another matter. During a “Performance Standard” structural test, it is assumed that the canopy opens normally. In the real world canopies don’t always open normally. As we know there are frequent aberrant openings, usually dubbed “line strip” or “line dump” openings. This type of opening has, in fact, occurred during drop testing by some manufacturers. The results have been catastrophic. Some of the manufacturers who have experienced this have built their products to withstand these aberrant openings. Some have not. Some have modified their products after the original testing with no consideration for the reduction of structural integrity. How can consumers protect themselves? Ask the manufacturer about the strength of their webbing and hardware. Ask them to what load the harness has been proved. Then ask their competitor to confirm this claim. Ask them if the harness is “fail safe”. That is, which location/joint will fail first and what will happen to the wearer if and when it does fail. The wearer should not come out of the harness.
The Ultimate Test
Time in the field = Proof of performance. It takes a minimum five years to “prove out” a new feature of a rig.
Container Flexibility
There are two choices for container comfort and fit. One is a soft flowing container which flexes and bends and is easy to pack. The down side of this choice, is that this type of container may “catch air”, and create excess drag. The other choice is a hard packed, molded container that is small enough to be completely out of the air flow, and will allow full body movement. This type of container must be shaped by design. Before you put it on look at it -- it should have a shape waiting to clamp onto your back. Modern design contour fit!
Container Fabric
There are several fabric types used in the manufacture of sport containers of today. They are generally divided into two categories: Parapac and Cordura. Certainly there is a sub difference of the base types. That sub division is usually defined by denier. military containers used a 420 denier Mil-Spec C-7219 Parapac. This fabric is specifically designed for use in parachute containers. There are deniers less than 420 available and they should be avoided except for decorative purposes. Cordura has proven to be a popular and durable fabric for use in containers in spite of it’s excess weight. Theoretically, Cordura is more ultraviolet resistant because the coarseness of the material casts a larger shadow protecting it from ultra-violet deterioration.
Reserve Container Design
There are two basic reserve container designs in common use today. They are internal pilot chute and external pilot chute. On the internal design multiple side flaps are cantilevered over the pilot chute to a locking loop through a grommet which is secured with a ripcord pin. The external system has the pilot chute sitting on the outside of the flaps with loops passing down through the flaps between the folds of the canopy to the back side of the container where they are retained with the loops through a grommet by a ripcord pin through the loop.
Main Container Design
Which flap closes first and which flap closes last? On some containers this is critical. Buy a container where it either doesn’t matter or where they can’t be assembled incorrectly.
Available Sizes
With the availability of over two hundred main canopies alone, container sizing has become an enormous challenge for container manufacturers. Generally, most mains are bigger than the reserve by a small percentage. The sizes of the canopies and the ratio between them should be close(See How To Select The Right Canopy For You). However there are times when you might need to vary from this practice, such as for an accuracy rig. The containers you buy should be sized for the canopy that will go into them. Over-stuffing and under-stuffing can cause problems i.e. cause the container to wear out more quickly by overstressing stitch areas and grommets, in the case of over-stuffing; premature openings, caused by pins falling out of loosely loaded loops, in the case of under-stuffed rigs. Be advised that similarly sized (square) main and reserve canopies seem to fly in unison better if you happen to have both open at the same time. This is a highly debated topic in recent years, with the world-wide move to square reserves and more frequent use of AAD’s.
Main Deployment Choices
In the beginning there were ripcords and spring loaded pilot chutes for deploying our mains from our backs, and reserves from our chests. This system worked by packing a conical spring loaded pilot chute, in compressed form, inside the main container, on top of the canopy and it’s devices. The container was held closed with a cone and grommet/pin system with the release pin on a cable leading to the release or ripcord handle. Pulling on that handle pulled the pin from a hole in the cone allowing the grommet to slip off of the cone, thus releasing the container flaps and allowed the spring to expand and spring out of the pack, hopefully. There were other variations on this theme, such as umbrella type springs, a even a springless pilot chute which was a hat (yes, a real hat!). To deploy, you removed your hat and flung it into the air; which brings us to the next generation in main deployment.
Hand Deploy / Throw-Out
While the hat trick was a little difficult, a pouch, external to the container, was devised. With the handle for the pilot chute mounted on the top or apex of the canopy, the springless pilot chute was folded into this container and the bridle to the container was Velcro’ed to the rig along its path to the pin on the container. The pin is curved to allow angular loading. Pulling the pilot chute out of the pouch with the handle on the top, and tossing the canopy into the free stream is all that is required to deploy the main. Pouches for this system have been mounted in several places, from the front of the leg strap, to the back of the leg strap, to the bottom of the main container.
The pull-out retains the sequence of the ripcord system and provides the added safety of keeping the springless pilot chute in the same container as the main canopy. It is equipped with a handle, mounted on the back, lower outside corner of the main container. Pulling that handle extracts the straight ripcord pin allowing the container to open, and the internally stored springless pilot chute to be put into the free stream. The handle on this system is mounted on the base of the pilot chute.
AAD On Main?
Generally in this sport, AAD’s are mounted on the reserve container. Some skydivers, and the entire "East Block", have however, elected to put their AAD’s on the main. It was explained to me this way. "I want my AAD on my main because my greatest fear is to be knocked unconscious in freefall. I would prefer to wake up under a malfunctioned main than I would under a malfunctioned reserve."(Al Kruger a.k.a. "Captain Hook"). Of course, having an AAD on the main would require a spring loaded pilot chute.
Reserve Deployment
Reserves must deploy in two different environments. Slow speed, after a cutaway, and high speed, in the event of a totaled main. According to TSO C23c, slow speed deployments are required to complete within 3 seconds after a cutaway. The test allows no more than 2 seconds of free fall after the cutaway before pack opening. If an RSL is used, the benefit of the speed acquired by the 2 second free fall is lost and the reserve must still deploy in 3 seconds. Trying to control the “not more than 2 seconds” rule is difficult, and is allowed only because, without an RSL, there must be some delay. The intent is for immediate deployment. Manufacturers have played games with this specification. Some have interpreted it by saying, “if it opens in five seconds after cutaway it’s OK”. NOT TRUE! The only test that can be trusted is the test where an RSL is used. This is a critical feature, as there are many combinations of canopies and containers in use today which do not meet this requirement. Your only protection is to see a video of the tests. DON’T BUY a system without seeing a video of its reserve deployment abilities. Take a stop watch with you when you view this video and time the deployment. Time it from pack opening to full canopy. Make sure that there is no more than 2 seconds from the cutaway to the time when the pack is opened. If your time on the deployment is more than 3 seconds don’t buy it.
The high speed requirement is not difficult to meet, but some do fail this parameter. It is generally accepted that a reserve should open in 350 feet, at terminal. That equates to about 2 seconds at 174 ft./second. The testing is done by throwing the dummy out at 500 feet, at speed. The test is not timed and is not difficult to meet.
Riser Covers (Main):
There are two choices for main riser covers. Open or trough type covers, and Velcro sealed closed covers. If you skydive on your chest all the time, then you might like the open or trough type. If you skydive in other configurations you will prefer the sealed type, as they don’t open when you are on your back. Recent improvements to the trough type include an "over riser" inside flap.
Harness Strength
There are several types of webbing used in the manufacture of personnel delivery harnesses. To understand the choices requires a little history lesson. Originally, harnesses were made of cotton webbing. During this era hardware was designed for use with the cotton webbing. We use the very same hardware today. When nylon was invented, it became apparent that nylon was infinitely better than cotton for use in most applications, especially personnel harnesses. Rather than retool the hardware, the nylon was then configured to be compatible with the hardware. The resultant product was 7000 lb. tensile, Type 13 harness webbing, identified by a black edge trace. At the same time Type 8 (Black Center Line, 4000 lb. tensile), and Type 6 (Red Center Line, 2500lb Tensile) were designed to be used with the Type 13 in a supplemental roll, where involvement with hardware and exposure to environmental hazards were not a concern. Additionally, Type 7 (Yellow edge trace, 6000 lb. tensile) was introduced at that time for use in cargo delivery, where no interaction with personnel hardware would occur. Some sport manufacturers have adapted this weaker webbing (Type 7) for use in sport harnesses. While strength has been a minor issue with this application, it does slip in the hardware and won’t hold proper adjustment.
Friction Adapters are the only hold over from the cotton webbing days. Most harnesses don’t use any other hardware, as additional hardware adds weight and creates a weak spot in the harness. Additionally, hardware can cause bruising of the wearers body. On harnesses where other hardware is used, for articulation for example, the consumer should know the ultimate strength of the hardware and its associated joint. A minimum of 4500 pounds, with a “fail safe” configuration is required for safety along the main lift web.
Harness Comfort
Sizing and fitting a harness is like sizing and fitting a suit of clothes. There are several benchmarks or “hard points” that must be held as the harness size changes. One is the point of suspension; it occurs at the top of the pectoral muscle in the hollow of your shoulder. Many rigs allow this point to rotate up to the top of the shoulder. This is incorrect and you will know it when you look under the shoulder portion of the harness and while the chest strap is keeping your mouth closed. If your harness suspends you correctly you will feel like you are sitting in a chair. This might require sliding your leg straps down under your thighs after opening. The other benchmark is the top of container. The harness must encircle your body while holding these two points. You should make sure that the harness you buy is custom made for you and that the manufacturer sizes your harness in both the main lift web and over-the-shoulder dimension. The harness must be comfortable in three different environments: in the air (in freefall), under canopy, and lastly on the ground. In the air we are usually on our bellies; under canopy, sitting in a chair; and on the ground, walking. The flex of webbing accomplishes this job just fine if the harness is configured properly.
Harness Materials
Harness materials should meet mil-spec., but that is not enough. The material must be used as design intended. The webbing should be “shuttle weave”(the weave of both edges look the same) as opposed to “needle weave”(the weave of both edges look different). A “shuttle weave” is a locking weave, that will not unravel if the edge is nicked or broken. Refer to The Parachute Manual, pg. 80 - , sections 4.060 through 4.062.
Comfort Pads
There are two kinds of foam used in comfort pads -- closed cell and open cell. Most manufacturers use open cell foam that they buy at the carpet store. Buy a rig that uses closed cell athletic padding that will float and not absorb water.
Riser Releases
The riser release system in common use today is the “3-Ring”, it is the de facto standard. There are several variations of this design in use. Due to some recent incidents where cutaways have been from difficult to impossible, I would anticipate additional variations or improvements. The 3-ring is a single point riser release system designed around three rings of decreasing diameter. Each is able to nest inside the larger with clearance for mounting webbing. They are secured and released with a locking loop, through a grommet, into a “push/pull” cable system that releases both sides. The housing pushes, while the cable pulls from the locking loop, which when released, allows the ring/levers to “tumble” open. There are two sizes available. The mini, which is capable of approximately 3600 lb. load and has about a 60 to 1 mechanical advantage, and the large or standard, which has more than a 200 to 1 mechanical advantage. The mini is generally accepted as adequate for normal solo sport jumping. The large is used for tandem, military and situations where high loading is anticipated. (See “The 3 Ring, What It Is And How It Works”)
Option Availability
You should look for a rig manufacturer who can provide you with the options your skydiving requires. Be reasonable, there are some options which might be dangerous. Find a designer with whom you can talk it over.
Pilot Chutes
Pilot chutes have become an included component in Harness and Containers, therefore they should be discussed.

Main pilot chutes were generally discussed in the “Main Deployment” section. They do have some additional features mentionable here. There is large hole mesh and small hole mesh and there are two types of canopy fabric in common use, Zero-P and F-111. The zero-p is a silicone coated F-111, and as such, has a lower permeability, both initially and in the long run. The initial difference is minor, and for all practical purposes doesn’t exist. However, if you consider the following you can make your own decisions about the fabric and the mesh. A colander or sieve is held under a slow running stream of water. The water passes through the sieve as fast as it enters. Increase the water flow and the sieve will fill up and the water will spill over the edges. This is equivalent to what happens with porous fabric being drug through the air.
There are two important aspects of the reserve pilot chute. As it is usually spring loaded, the “jump” or launch of the spring is important. Additionally the drag capability must be considered. While you can judge the jump with your eye (remember to judge it coming out or off of the container) the drag capability is more evasive. You could drag them through the air with a fish scale but your airspeed might vary from jump to jump. The only way to accurately determine the coefficient of drag, is in a wind tunnel test. Poynter reports on tests of several kinds which might be enlightening and help to establish a mental base line. You must ask the manufacturers and judge their answer. If they can’t supply a “Coefficient of Drag” number beware!
Auxiliary Systems
Read our What you should Know About RSL’s article.
Will the rig of your choice accept the AAD of your choice? Has the rig maker approved the AAD makers installation? Has the AAD maker approved the rig makers instructions? The important thing to remember whenever you consider an AAD, is that the container, not the AAD, is the primary life saving device. The AAD must not interfere with the proper function of the TSO’d container and its TSO’d reserve.
John Sherman

April, 1996

© The Jump Shack
Reprinted with permission

By admin, in Gear,