A Triacian (sp??) round parachute (either 23' or 26') has a characteristic cat eye slit at the apex of the canopy.
John LeBlanc has been designing canopies at Performance Designs for 17 years. Before working at Performance Designs, John started jumping at 16 years of age. He earned a degree in Aerodynamics. In his early jumping days, he borrowed gear and tried many different parachutes. He wanted to know why they flew the way they did.
After landing well or poor, John asks himself, "Was it me or the parachute?" One has to ask themselves this question also while designing parachutes. He always asks himself, "Was it me or the parachute?" Ask yourself this question. A typical skydiver wants to protect his ego and tends to say it was the parachute.
To enhance his canopy control awareness, John LeBlanc would talk to himself as he is flying his canopy.
Ask yourself, "What do I believe is true?" There's all kinds of possibilities. It's possible that you might misunderstand what you are told about flying canopies. Listen with a critical ear. Try out the ideas to put them in your frame of reference. Try something different.
There are misconceptions about wing loading. For more information visit the Performance Designs web site at: http://www.performancedesigns.com Follow the link for seminar notes and download the document titled, "Wing Loading and its Effects." The direct link to the document is: http://www.performancedesigns.com/docs/wingload.pdf
First, let's define wing loading. It is a measurement comparing the total weight supported by the canopy and the size of the canopy. When determining your exit weight, don't forget about your weight vest (if you are using one). For the size of the canopy, use the manufacturer's published size. For example, a skydiver with an exit weight of 190 lbs jumping with a 95 sq ft canopy has a wing loading of approximately 2. That's exit weight (in pounds) divided by the size of the canopy (in sq ft). Sometimes jumpers make the mistake of making the calculation by dividing the exit weight into the size of the canopy. For example, one may mistakenly tell a 150 lb student who is jumping a 300 sq ft student canopy that he has a wing loading of 2. If you tell that student that 2 is too high of a wing loading and that he needs to have a wing loading of 0.5, he will get a canopy that is too little! Watch your language!
In terms of speed, all 190 sq ft canopies, whether it is a Falcon, PD, Stiletto, Sabre, etc., are similar to one another. However, they will all turn different, flare different, etc. Don't get hung up in model name of parachute before considering its size.
A person evaluates the speed of a canopy according to their frame of reference, which is based on their past experience. It's possible for two jumpers with the same exit weight, same number of jumps, and same canopy and one of the two jumpers will think the canopy is fast and the other does not. It depends on what the jumpers have jumped in the past. Don't project your frame of reference onto someone else. If your exit weight is 220 lbs and you are flying a 135, you might tell a 150 lb jumper that a 150 will be docile and easy to fly. That's projecting your frame of reference. Look out for others who may be projecting their frame of reference upon you! Ask them what they jump and what canopies they are accustomed to.
People believe you must load a high performance canopy to fly better. This is not true. People have defined themselves by how little a canopy they jump. Although, some canopies are designed to fly on edge of stability. These canopies need more wing loading. Examples include the Nova and the Velocity. The largest Velocity available is a 120. Some people believe a canopy will not flare well if it's not loaded enough. This is not true. Try flying every size of Sabre starting with a 230 sq ft and working to the smaller sizes. For a light weight jumper, the Sabre 150 feels mushy to flare. However, a light weight can learn to actually level off during the flare under a 230. This illustrates that technique is more important. Using a smaller canopy does not necessarily result in a longer swoop. After downsizing, you may find that your swooping distance is shorter. This is because you were flying your larger canopy more skillfully.
If you comfortable at a certain speed, then you have the right size for you.
Let's test your understanding of canopies with the following questions:
1. Two jumpers with vastly different exit weights will have the same performance if they have the same model of canopy, sized for each of them with the same wing loading. True or False
What is performance? It's how you define it.
2. It is possible for two jumpers with vastly different exit weights to have the same performance, but the lighter jumper must load their canopy a little more heavily. True or False
3. It is possible for two jumpers with vastly different exit weights to have the same performance, but the lighter jumper must load their canopy a little more lightly. True or False
4. When you downsize to a smaller canopy of the same type, you will have the same glide angle, but you'll go faster. (Or, it will be slower in the case you go to a larger canopy.) True or False
The following concern two jumpers with exit weights of 135 and 230 pounds, flying a Sabre 135 and 230 respectively. They have the same wing loading of 1.0 lb./sq. ft.
5. The canopies will provide identical performance for both jumpers. True or False
6. The jumpers will have the same glide angle and speed. True or False
7. The canopies will have similar handling and responsiveness in turns. True or False
8. The canopies will have similar stall characteristics. True or False
9. Assume the lighter jumper stays with a Sabre (a rectangular canopy) but the heavier jumper changes to a highly elliptical canopy at the same wing loading, for quicker turns. In this case, the heavier jumper will definitely be capable of out turning the lighter jumper. True or False
10. Assuming that both jumpers have similar skill levels, and both are planning to transition to smaller Sabres to have a higher wing loading, they will have similar challenges in achieving nice no wind landings. True or False
The answer to all of the questions is false.
The physical laws of nature do not scale. For example, the viscosity of air (the distance between air molecules entering the canopy) does not change proportional to the weight of the jumper nor the size of the canopy. The laws of inertia indicate that something that is heavy is slower to change.
The change in performance resulting from downsizing is not entirely due to the change in wing loading. That smaller parachute is a "different" parachute. Handling is a result of the aerodynamics of the canopy. Speed is a result from the wing loading. Try a bigger canopy and wear a weight vest so that you have the same wing loading. You will have the same speed but when you pull a toggle you will know you have a bigger canopy. Larger canopies have longer lines and smaller canopies have shorter lines. Canopies with longer lines have a more sluggish response to toggle input. The jumper must move out to the side a greater distance to establish a turning bank angle. The canopy must accelerate the jumper out to the side and then stop at a bank angle.
Let's talk about the flare. Watch a plane land. Its nose raises, in other words, the angle of the wing changes. Your canopy needs to do the same. You swing out in front of the canopy during the flare. Canopies with longer lines require more energy to flare, therefore the flare is more sluggish. Smaller canopies pendulum much faster and provide a quicker response.
A smaller canopy at same wing loading will lose more altitude in a turn and it will stall more radically.
Light weight jumpers face more challenges than heavier jumpers. First, when they are students, they learn at a slow flight speed at a lighter wing loading. Often, light weight students and heavy weight students jump with the same size student canopy. Light weight students always land softly. The student canopy is so forgiving that they don't need to learn good technique for flaring. A heavy weight jumper will receive coaching on their flare technique from experienced jumpers and the instructor. However, light weight jumpers get off student status without learning good canopy control. Females will promptly admit fear. Males hide their fear. When a light weight jumper downsizes, flying with a higher wing loading is more scary. It's much faster than that student canopy. Handling is also more responsive. Light weight jumpers often downsize too much at the beginning. Since they lack skill, it is scary.
At the same wing loading, a heavy weight jumper will have more sluggish response compared to a light weight jumper. However, they will both have the same speed. Light weight jumpers tend to settle on a lower wing loading simply because they are lighter. An experienced jumper looks for an ideal response which is not too slow, nor too fast. A lower wing loading provides that response to a light weight jumper. Heavy weight jumpers enjoy that ideal response at a higher wing loading. However, heavy weight jumpers must accept coming in faster to have that degree of responsiveness.
Jumpers want speed to get back from a bad spot. But they want to land well on no wind hot day.
Heavy weight jumpers tend to choose elliptical canopies and light weight jumpers tend to choose rectangular canopies.
It is especially recommended that light weight jumpers do not skip a size while downsizing because these sizes are 100 sq ft and smaller. A light weight jumper transitioning to a 79 is in for a greater surprise than a heavier jumper transitioning to a 103 from a 120.
In the PD line of canopies, the Stiletto is most responsive to toggle input. Canopies released after the Stiletto require more input to roll. This is because John observed jumpers oscillating on the roll axis while swooping with their Stilettos.
Some jumpers do not differentiate wind conditions from the speed of the canopy. For example, a jumper may comment that a Cobalt 120 (in a 10 mph headwind) lands slower than a Stiletto 120 (in no wind).
Some jumpers do not observe how much control input they make in order to make a move. They just feel it, wanting to achieve a certain turn rate. They pull the toggle less on a Stiletto and more on a Sabre without realizing.
There are different ways to measure canopy size. A 120 from a different manufacturer may be a little larger or smaller.
The PD 9 cell was designed to be easy to land. The prototype was very sensitive and only small inputs made the difference between flight and a stall, which would result in a foot slapper landing.
The Excalibur was an F111 with more speed and flare performance. Jumpers started to do hook turns using the toggles. Jumpers took advantage of the Excalibur. Jumpers jumped it with a higher wing loading.
PD decided that an ideal canopy must be conservative, easy to flare, open soft, and impossible to stall. The Sabre was born.
The Blue Track was the first elliptical canopy on the market and it was very responsive. Jumpers enjoyed the turn rate of Blue Tracks. However, Blue Tracks opened too hard. The Stiletto was born. It has a flatter glide, quick on toggles, and offered the best landing performance. The Sabre dives more, therefore, it is easier to flare and land. The Stiletto was not stall proof like the Sabre. On opening, the Stiletto snivels.
There was interest for a 7 cell canopy in the market. The Spectre is like a refined Sabre 7 cell canopy. You can swoop or land like a 7 cell. The Spectre was born because jumpers were purchasing the Stiletto for its slow openings. The Spectra was made to open slow and was aimed at the American market. Europeans tend to not care about 7 cell canopies.
The Silhouette is a semi-elliptical 9 cell canopy with a ZP top skin. It is easier to pack and designed to be flown at a more moderate wing loading. The Silhouette was aimed at the European market, however, Europeans were attracted to the Spectra! At that time, jumpers enjoyed canopies that dove, were less responsive and had airlocks. Icarious in New Zealand approached PD. Precision offered the Crossbrace series of ZP canopies. The Velocity was born. It dives crazy, slows well, and requires larger toggle input. PD customers have become more conservative. The Vengeance dives more and slows well.
Sabre was designed in 1989 and was introduced in 1990. Today's jumpers are better canopy pilots. The Sabre2 is more responsive.
Jumpers have bad pilot skills. The problem is that we think it's those guys when, in actuality, it is us!!
The Sabre vs Spectre. The Sabre doesn't do deep brake S turns. The shorter cord increases the roll response. The Spectre has more low speed characteristics. Jumpers should learn the low speed characteristics of their canopy. They downsize and then believe it's not possible to fly slow. The Sabre has docile stall characteristics and is less responsive. Even with sloppy flare technique, you can still achieve a zero rate of descent. A jumper can swoop or shoot accuracy with a Spectre. To swoop with the Spectre, it's necessary to flare later with a quick pull on the toggles to achieve level flight. To do accuracy, use slow toggle input to achieve the slowest speed and then sink.
Instructors teach students to flare slowly. In this way, nothing dramatic happens. At Skydive Chicago, Roger Nelson provides a 1, 2, 3 flare count on the radio. On the count of one, the toggles should be at ear height. On the count of two, the toggles should be at chest height. And on the count of three, the toggles should be down.
If you want to turn faster, be sure that the brakes do not pull the tail down when in full flight. Also, don't pull the opposite toggle to stop the turn.
Regarding determining appropriate canopy performance for a jumper... Ask about the number of jumps they have and over how much time.
Choose to either try a faster canopy in the same model or to try a more responsive canopy at the same size.
A 105 slows better in the flare than a 120 but it's more scary on final because it is faster.
Many instructors or experienced jumpers swoop and do not know how to fly a straight-in approach to landing. When swooping, only small toggle movements are necessary. A straight-in approach requires a more aggressive flare, a more quick flare to pitch the canopy so that you swing out in front of the canopy. Larger canopies require more input. For example, under a 210, a quick flare is needed to pitch the canopy. Then, the pendulum effect starts to move you back. You have to push the toggles more to keep in front of the canopy. The failure to use more quick flare to level out installs the belief that you must load a canopy more.
Find the ideal speed of toggle movement to make the ideal pitch change. On a no wind day, pick out the stationary point in front of you. The angle between the stationary point and the horizon is the pitch angle you need. After pitching the canopy, hold that pitch by continuing to lower the toggles. If you can't precisely change the pitch angle, you are flaring too quick. If you change the pitch too quick and oscillate, you'll end up running it out. While up high, try flaring slow and flaring fast. Flare fast and hold it there.
When you are under your canopy, the hanging point is around the B lines.
While up high, explore flat turns, diving turns, and climbing turns. The climbing turn is how you carve and avoid obstacles as you are leveling off for landing.
If you change the pitch of your canopy too low with the toggles at too slow of an airspeed, you will have a foot slapper landing.
While you are leveling off for your landing, you should be able to reach the ground with your feet. It is OK to tuck the legs a little bit, but don't twist your legs. People unconsciously let up on the toggles when stepping down.