Selecting the Right Canopy © PIER MEDIA  2001  | HOME  |  WING LOADING YOUR RESERVE | WING LOADING YOUR MAIN

Our concern in is to assist in your canopy selection process. First and foremost, it is important to understand the necessity of flying a parachute that is appropriate for your skill level—your skill level today, and not where you fantasize yourself to be in the future. 

There are many factors that come into play, such as competence, DZ altitude, density altitude, etc. Discuss your canopy style and size with a canopy manufacturer, as well as your instructor or safety officer at your DZ, before making a performance style and size selection.

 There are four main factors you will need to consider when selecting a canopy:

* Your exit weight

* Your experience and ability

* Wind conditions and field elevation at your DZ

* The type of canopy ride you want

 There are too many canopy "model specific" performance variations for us to detail in this book. The performance of any canopy will vary greatly with wing loading. Almost any canopy can go from a student canopy to a rocket ship depending on the size ordered and the weight of the user.

 Primary Rule To Follow

 Select a canopy that will be forgiving of your piloting errors, because you will make errors. If your canopy flies too fast for your skill level, descends too fast, or if for any reason you cannot control its performance when you need to, it can seriously injure or kill you.

 Talk to the Manufacturers Before Making a Decision

 The canopy manufacturers are the best consultants for selecting a parachute. If they are not the experts, there are none. They have wing loading guidelines for their parachutes that you should follow. Also, their owner's manuals contain important information about the canopy's flight characteristics. Read them.

 In addition, a dropzone instructor or Safety and Training Advisor (S&TA) might be helpful with your decision if he or she knows you and your present capabilities. Ask around and find a highly knowledgeable and experienced person on the dropzone who will consider your safety over your desire for unfettered fun.

Be Careful Basing Your Decisions Solely On Dealer Recommendations

 Be careful not to let a salesperson dictate what you should buy without answering some of your questions first. Learn as much as you can before making a purchase—while most retailers out there are reputable and knowledgeable, some only want to sell what they have in stock.

 Much has changed in our sport since the original conception of this book. As recently as 1997, it seemed extreme if a 195-pound jumper (total exit weight including gear) with only twenty or so jumps purchased a brand new, zero-porosity (ZP), 190 square-foot parachute. This would have placed the jumper above most manufacturers' published wing loading recommendations. Any parachute dealer concerned with liability would have attempted to convince this jumper to consider a larger, more docile, 230 square-foot canopy. Perhaps a 210 square-foot parachute, as a compromise. 

It is more commonplace today that progressive dropzones teach their students a great deal more about flaring, obstacle avoidance, navigation, and traffic patterns. Moreover, today's customers want the smallest possible canopies in order to have the smallest possible containers.

 Students are graduating with the same desire to have the smallest and "sexiest" looking containers, as would be expected from their jumpmasters. Surprisingly, today's novice can actually handle a reasonably smaller ZP canopy than novices in past years if they demonstrate the abilities and are adequately trained and supervised. Still, we feel it should be mentioned, again and again, that taking the conservative approach and factoring in a higher margin for error will help deter a frightening and expensive visit to the emergency room. The conservative approach is to buy a canopy that may be one size bigger than what you think you can handle. It will be easier for you to master a slightly more docile canopy, if mastery is what you seek. Remember skydiving is and always will be a very high-risk sport, with a lot of the risk involving canopy piloting. Be patient with your downsizing plans. Pay your dues with time in the sport, not with broken bones or bloodshed. Outgrow your parachutes, and then fly them some more to achieve mastery.

 Downsizing and "Demo-ing"

 In the beginning one might move through a number of different canopy sizes and models, especially if you rent or borrow school gear. You should be completely comfortable in every situation with whatever canopy you are currently flying, exhausting all areas of learning before graduating to the next size down. As with everything in this sport, it is always wiser to take the more conservative approach when downsizing and testing higher-performance parachutes.

 Try to demo the canopy you intend to buy. When test jumping a canopy for the first time, make sure the wind is suitable for your skill level and that you receive instruction from a very current, competent, and proficient canopy pilot. You will want to test the canopy over a period of several jumps in varied conditions. Try it in moderate winds and in no wind. If you are downsizing, do so gradually—one size at a time until you can handle the speed and performance of the next size down. Do not skip sizes.

 Take more precautions when test jumping than normal. You may have to stay on the ground on particularly turbulent or strong wind days. Judicious discernment is the guiding secret to longevity in this sport. You heard it here.

 Getting Down to Business

Picking the right parachute is easier than you might imagine. Canopies are built in several different models and sizes, providing a wide range of surface area and flight characteristics. Let us begin by defining some key terms for the uninitiated.

 Wing Loading

Wing loading refers to the total suspended weight under the canopy, including the weight of the canopy itself. How much or how little you load a canopy will greatly affect all of its inherent characteristics. 

Wing loadings are used as a guide to this combination of size and weight that will determine a canopy’s performance. Wing loadings are measured in Pounds (at exit weight) per Square Foot (of canopy area) or “PSF”, and are calculated by dividing the exit weight into the canopy size. 

It is not necessary to heavily load any high performance canopy to make it fly and land softly, a common misconception even among many experts. If you are not getting good landings on a properly designed canopy flown at a lower wing loading, you are not flying or flaring correctly.

 If the wing loading is greater than the manufacturer's recommendations, safe and comfortable landings may be difficult to obtain, even for experienced jumpers under ideal conditions. Less experienced jumpers will be exposing themselves to greater dangers. Turn rates, forward speed, and rate of descent all increase on overloaded canopies. Control range is shorter and there is greater potential for stalling (collapsing) abruptly with little warning. Lower speed landing techniques may not work. Therefore, for the less than experienced pilots, a front riser turn or other type of hook turn may be required to generate enough forward speed for a softer landing. Sound dangerous?

 With too heavy a wing loading, the parachute sinks like a bag of cement. It may land terribly unless you have the skill to obtain maximum glide and minimum sink without stalling the canopy when flaring, a skill that comes with much practice and hundreds, if not thousands, of landings.

 It is also less than desirable to wing load a canopy too lightly, especially in higher winds. With a low wing load the canopy may "float", or back up, and/or collapse during even minor turbulence, requiring the jumper to use special handling techniques to recover and maximize any lost performance. 

Heavily loaded and lightly loaded canopies are extreme choices. Canopies can be flown safely under extreme wing loading, provided the pilot is skillful enough. The greater the extreme, the greater the skill required. It is not absolute enough to state whether or not one can under or overload any canopy. Pilot skill must be factored in. Extremes have been tested satisfactorily in either case, but safety and prudence must be the desired goal. 

Manufacturers have wing loading charts to help consumers in choosing the right canopy. Below, table one is an example of a manufacturer's wing loading recommendations for one of their canopy models. 

We have grouped wing loading ranges into six different classes of performance in order to explain the performance you may expect within each wing loading class. There is a gradual change in performance between the classes. The class description describes the midrange of each class, and the wing loadings at either end may tend towards another class.

Class 1 Docile Canopy (.5 to .75 Lbs/SqFt wing loading)

This wing loading will perform basically as a docile canopy. You may wish to choose a canopy in this range if you are very unsure of your ability, physically injured or disabled in some way, elderly or frail, or as a student canopy. A canopy in this class should not be jumped in over 15 knots. These canopies are easily affected by turbulence.

Class 2 Docile (.75 to 1.00 Lbs/SqFt wing loading)

Still a very docile range. This would suit an advanced student canopy or a first canopy for someone preferring to err on the safe side. Again, affected by higher wind conditions before most canopies would be.

Class 3 Mid Range (1.0 to 1.25 Lbs/SqFt wing loading)

This midrange canopy loading is a good benchmark to start from. This wing loading is high enough to start having fun, yet low enough that a competent low time jumper could handle one as a first canopy and still have a canopy they want to be jumping after a couple of hundred jumps. This is getting into the range that must be treated with respect because your mistakes are less forgiving. However, there is still a reasonable margin for error. Most of the canopies sold today are in this range. From this loading up, most wind conditions allowable for jumping are not a problem.

Class 4 High Performance (1.25 to 1.65 Lbs/SqFt wing loading)

Now we are having fun. However, the potential for danger has also increased. Turn speeds are increasing, air speeds and speed ranges are increasing dramatically. There is a fine line between what is fun and what is safe. Canopies in this range must be flown with skill all the way to the ground. Recovery arcs are generally over 200 feet and toggle input movements are getting noticeably shorter. A high degree of experience and competence is necessary to handle a canopy in this range. Flying a canopy in this range must be done by feel. Every maneuver must be well planned ahead of time, as things are happening very quickly. With a high wing loading turbulence will affect the canopy less, but remember you are traveling much faster if affected. Being dropped half a meter by turbulence under a class 2 canopy is not going to affect your stand-up landing, but being dropped half a meter in the middle of your ballistic turf surf could ruin your summer. The same goes for other obstacles. Buildings, fences, people, other canopies, etc., have much more impact at high speeds. Even uneven ground or short landing areas should be considered obstacles. These canopies will still be traveling horizontally in nil wind conditions. A collapsible pilot chute is recommended. Lowering the slider and loosening one’s chest strap is suggested.

Class 5 Extreme (1.65 to 2.00 Lbs/SqFt wing loading)

Not for the fainthearted. If you are one of the few people that want to fly a class 5 canopy, consider every aspect of what you are doing very carefully. On the upside there is very exhilarating airspeed, quick response times, and powerful maneuverability. On the downside our margin for error has reduced to almost nothing, compounded by the fact that if an error occurs we are almost certainly traveling at speeds that can maim. If you have or are considering a class 5 canopy, we cannot tell you how to fly it in this overview—we must assume you know what you are doing. Most people flying class 5 canopies do not fly them to the limits of the canopy, and the performance they achieve from their canopy could be achieved from a class 4 canopy flown to its limits with a far greater safety margin. These canopies generally have to be run out on landing. They must be fitted with a collapsible pilot chute. Lowering and collapsing the slider and loosening the chest strap is recommended. Canopy recovery arcs can be over 400-foot radius. The step from a class 4 canopy to a class 5 canopy can be quite large. For example, to an 80-kilogram jumper with gear and weights, the difference between a 105 and a 95 feels similar to the difference between a 130 and a 105.

Class 6 Ballistic (2.0 to 2.4 Lbs/SqFt wing loading)

If you are considering this, you do not need an explanation.

 Aspect Ratio (AR)

 One way to define the aspect ratio of a canopy is the relationship between the span (wing tip to wing tip) and the chord (straight-line measurement from front to back) of the canopy. Another slightly different expression is: Span squared, divided by the area- a formula that works for both elliptical and square canopies.

 High Aspect Ratio (HAR) Canopy

 When the span of the canopy is more than twice the chord length (2.5:1 AR), it is a HAR canopy. HAR canopies have a greater glide to sink ratio (glide ratio) than lower aspect  ratio canopies. However, the canopies design also plays a significant role in this as well. With most  HAR canopies, you get what we deem to be a high performance canopy. Because of its ability to cover greater distances and yield softer landings, most of us want the performance of the HAR parachute. There are other characteristics that define a high performance canopy.

 Low Aspect Ratio (LAR)

 The span of the LAR canopy is less than about twice the chord length (less than 2.2:1 ratio). Its configuration makes it more square in shape. It is generally a more docile parachute. Reserve canopies have a lower aspect ratio than mains.

 Glide Ratio (GR)

 This refers to the canopy's horizontal movement, or glide, in relation to its sink. A high GR canopy flies at a greater rate horizontally than it will sink. An average example of a low to medium performance canopy is two feet forward for every one foot downward. The higher the GR, the more ground that can be covered in flight.

 Defining High Performance

 The term "high performance" is not a synonym for speed exclusively. It also includes:

* High Glide Ratio (longer glide equals greater distance covered, but not always.)

* Characteristics in slow flight (canopy's stability and ability to maintain pressurization)

* Response to toggle or riser input. Is front risering smooth and stable with no bucking?

* Opening characteristics

* Landing characteristics

Canopy design, airfoil, trim angle, materials, and wing loading affect these characteristics.

With today's popular parachute models performance increases with higher wing loads, and requires more experience to operate safely. Overloading (weighting too much) the canopy will result in a loss of performance. Different manufacturers have different assessments of the capabilities of their canopies and their customers, so be wary of comparing the specifications from different manufacturers.

Zero-Porosity (ZP) & F-111 Fabrics

 ZP fabric is impregnated with a silicone-based product that makes the fabric more resistant to wear and aging. This coating is what makes the fabric feel so slippery. The slippery nature of ZP canopies fades in time, but they still retain their ability to hold air in for thousands of jumps more than an F-111.

F-111 is a non-coated, rip-stop nylon fabric. It is more susceptible to porosity as it ages. They are initially able to retain the air inside, but as the material becomes increasingly more porous after several hundred jumps and exposure to the elements, the openings and performance degrades.

F-111 canopies have a shorter life, which means that they must be retired sooner than ZP canopies. Eventually, the flight characteristics diminish and flaring becomes less of a thing of beauty. They tend to “die” on flare, thumping the jumper just a bit. This is the time to give it up. Let the kids have it, turn it into a tent, hang it from the ceiling. Alternatively, with ZP canopies a new line set will usually rejuvenate them to the point that you will believe you have a new canopy over your head even after a couple thousand jumps. Even the manufacturers cannot tell us how many jumps are too much for a ZP canopy right now.

Though it should be the least consideration of your decision making process, the resale value of a ZP canopy is better than that of the F-111.

There are also canopies that are made with both F-111 and ZP fabrics. It is customarily the top skin that is ZP and the bottom that is F-111, thus they have a reduced pack volume, increased durability, and retain their original flight characteristics longer than an all F-111. They also cost less than a canopy built using all ZP material.

 High Aspect Ratio Elliptical

 As its name suggests, the elliptical canopy has a tapered profile along the tail (the end cells are shorter from tail to nose than the center cells are). This significantly reduces wing tip vortex (turbulence), reducing induced drag.

 Ellipticals generally have a higher aspect ratio than their non-elliptical cousins, increasing the glide ratio and usually the airspeed. Some are designed specifically for the higher wing loads that experienced pilots usually put on them.

 When heavily loaded, elliptical parachutes fly very fast. The landing and stall characteristics may not be as forgiving as a straight wing. Response to input is more precise and immediate, and the "feel" is more sensitive. What this means at any wing load is that they require a more experienced pilot who can control the higher speeds and increased sensitivity to input.

 Ellipticals that were designed to open slower than other squares, may have more "twitchy" openings (prone to line twists or off-heading openings). Even with lighter wing loads, not all ellipticals are safe for novice or intermediate jumpers. However, in both seven-cell and nine-cell configurations, there is a class of intermediate ellipticals, or slightly tapered canopy designs, provided that they are reasonably loaded.

  Seven-Cell Versus Nine-Cell

 Generally, the seven-cell canopy has a lower aspect ratio than a nine-cell, making them look more square and less rectangular. Although there is a range of HAR seven cells being built today, most are still slightly lower aspect ratio. As stated earlier, the higher aspect ratio of a canopy affects speed and glide, and it is safe to say that all "high performance" canopies so far are HAR.

 The modern seven-cell parachute, even with its inherently lower aspect ratio, does not fly slower than a nine-cell. Some may react a bit slower, some faster. Some seven cells land more softly, even with limited pilot skills. Most of this is dependent on the overall design of the canopy and the wing-load. Some seven cells are designed to be more agile in deep brakes, and feel more "zippy" with toggle turns. Seven cells tend to open softer and are more forgiving to sloppy packing. They also have a smaller pack volume than nine cells. For these reasons, reserve canopies, CReW, and many accuracy canopies are seven cells.

 Reserve Canopies

 Follow the wing loading recommendations for the reserve canopy you intend to buy. Table three, below, is a wing loading chart for popular reserve.

 Age & Ability

Considering your age and physical condition must also be weighed into the equation of gear selection. Ask yourself the following questions:

 * Am I athletic and limber?

* Am I in good, fair, or poor physical condition?

 Can you run off the excessive forward speed of too small a canopy, especially on a high density, no wind day? Perhaps you cannot run as well or as fast as you used to. Maybe you do not want to have to run at all. Are you lacking in strength, flexibility, and muscle tone?

 Wind Conditions & Field Elevation

 Is it predominantly windy where you jump? Or is it rarely windy? If you jump where it is windy most of the time, you can get away with a smaller canopy. You do not want to risk blowing off the DZ, after all. If it is only sometimes windy and mostly calm at your dropzone, anticipate having to judge the distance of your glide on those zero-wind jumps. Remember, the wind stops blowing everywhere eventually, so do not hose yourself. 

Also consider the dropzone elevation and air density, especially on warmer days in summertime. Your parachute is going to display decreased performance capability at airports above 2000 feet. On high temperature, high humidity days (the air actually gets thinner), you will have more difficulty stopping your canopy. The higher the elevation of your dropzone, the more square footage you should have. Otherwise, anticipate a longer distance to bleed off forward speed. Above 2000 feet is where this factor becomes very evident. Your safety and enjoyment depend on matching your canopy with your ability and weight. You want a canopy that is capable of covering reasonable distances, flies well and predictably in slow flight and turbulence, has predictable openings when packed correctly, and lands you softly when you flare properly. We will cover technique later in the book.

Wrapping It Up 

The decision whether to purchase a seven-cell or a nine-cell, ZP or F-111, elliptical or non-elliptical canopy might only boil down to your budget, and whether or not you are buying new or used. As a conservative choice, some may perceive a used F-111 canopy as a better choice for a first time buyer. This is not always the case. A worn out canopy may be grossly out of trim and have no flare left at all, making it harder to fly than a brand new canopy or a ZP canopy with like-new performance. 

Many people with physical limitations, such as knee, hip, or back problems opt for the seven-cell. Some never anticipate becoming a "hot-dog" canopy flyer and do not see a need for anything that approaches too high performance. With a big seven-cell canopy, these jumpers are amply satisfied.

Grow out of, rather than into, your parachute. Buy the canopy that will leave you unbroken and allow you to make your next jump. Your primary concern for selecting both your main and reserve canopies should be having enough material over your head to land softly anywhere, every time you jump.

 In the age of "small is cool", your gear may look bigger than you would like because of larger pack volume, but a smaller pack volume will not make you a better pilot. It will not get you back to a safe landing area either. Select parachutes you can easily pilot in a number of ordinary and extraordinary situations. Select a main and reserve that are sized compatibly and fly compatibly if both are accidentally deployed simultaneously.