Foundations of Flight | Ram-Air Parachute Anatomy—Fabrics
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Foundations of Flight | Ram-Air Parachute Anatomy—Wing Properties
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Foundations of Flight | Ram-Air Parachute Anatomy—Cells
Brought to you by Niklas Daniel and Brianne Thompson of AXIS Flight School at Skydive Arizona in Eloy. Images by Bruce Fournier.
In the photo above, the area that makes up the canopy’s center cell is highlighted in red.
It is important for jumpers to have at least a rough understanding of the different areas and features of their ram-air parachutes. Whether you are trying to describe a specific part that needs maintenance to a rigger or you are discussing your last landing with a canopy coach, a common language and terminology can help avoid confusion. The following provides a look at the internal components of your parachute that are hidden from view.
Concept: Cross-Sectional Area
A cross section provides a two-dimensional view of an object as if it were cut in half, revealing details of its inner workings. This can help shed some light on very specific areas, although they will make up only a small piece of the puzzle. There are generally six vantage points from which to view a cross-sectional area. These are typically at right angles to the three axes:
Equipment: Cells (Longitudinal Axis View)
In the previous article we defined what a ram-air parachute is and how to check if it is working properly. Now we will take a closer look at what the air is being rammed into: the cells.
In simplest terms, a cell is the space that is occupied by air when a parachute is inflated. The word “cell” comes from Latin and means “small room.” In the case of a parachute, the ribs make up the walls, the bottom skin is the floor and the top skin is the ceiling. The nose (leading edge) of the parachute has openings that capture the relative wind, pressurizing the internal structure of the wing as the closed trailing edge traps it. We’ll cover more details about these features in the next issue.
A parachute can have any number of cells, but most common sport parachute designs have seven or nine. Most sport parachutes utilize a bi-cell design, meaning there are two rooms per cell. Therefore, each cell has three ribs, two which are called loaded ribs (because they have suspension lines attached to them) and one in the middle of the cell that is not loaded. The purpose of non-loaded ribs is to provide additional connection points between the top and bottom skin. This helps shape the parachute into a more efficient wing.
Information about AXIS’ coaching and instructional services is available at axisflightschool.com. The authors intend this article to be an educational guideline. It is not a substitute for professional instruction.
More educational skydiving content, as well as this free article, is available by downloading the AXIS Skydiving app on your smart device.
AXIS Skydiving App
Foundations of Flight | Ram-Air Parachute and Canopy Check
Brought to you by Niklas Daniel and Brianne Thompson of AXIS Flight School at Skydive Arizona in Eloy. Images by Bruce Fournier.
Welcome Back!
After taking a two-year break since the last Foundations of Flight installment, AXIS is excited to announce that it is back with a new focus and look. Past articles (available at axisflightschool.com and parachutist.com) covered a wide range of skills and disciplines, but the new series is focused on specific canopy-piloting concepts. Using illustrations from the AXIS Skydiving app, this column will discuss one aspect—such as construction, a physics concept, a procedure or a flying technique—of a specific piece of equipment. Think of this column as a supplement to professional canopy coaching and a conversation starter rather than a substitute for training.
Introduction
There is much more to a parachute than just a nylon wing and some strings. Each component—which includes the canopy pilot—contributes to the performance of the parachute. A skydiving parachute is first and foremost a lifesaving device that is intended to be deployed at freefall speeds. Therefore, their design and construction are in many ways limited by their primary function. The canopy ride is not a necessary evil that lets you jump again, but instead completes the skydiving experience with a skill set all jumpers share. Developing skill under a wing that is appropriate for your level of experience and currency is much more rewarding than rapidly downsizing or relying on gimmicks. If you are looking for higher performance, approach the progression as growing out of a wing rather than into one.
Equipment: Ram-Air Parachute
A ram-air parachute is a nonrigid-textile wing with an aerodynamic cell structure. Inflated by the relative wind, a parachute requires constant pressurization to produce an airfoil shape. This is accomplished by using the airflow created as a parachute moves through the air, which gives it the name “ram-air.” Most commonly made out of a ripstop nylon, ram-air parachutes are flexible wings which are capable of much more complex behaviors than a ridged fixed wing found on an airplane. Ram-air parachutes have an arc-anhedral design (curved), which places the wing tips below the level of the center of the wing. The arched wing shape has spanwise (side-to-side) bumps, which are the result of the bulging of each cell as they are inflated with air.
Concept: Canopy Check
To determine whether you have a properly functioning main parachute, ask yourself these three questions after you have thrown the pilot chute:
1| There? Visually confirm that there is parachute fabric over your head.
2| Square? Determine if the shape of the wing is symmetrical.
3| Flare? Ensure you can steer and land the parachute using a controllability check. This entails making left and right turns, as well as a full flare (a simulated landing).
If the answer to any of the above questions is “no,” and you are unable to remedy the situation, proceed with emergency procedures at or above your decision altitude.
Information about AXIS’ coaching and instructional services is available at axisflightschool.com. The authors intend this article to be an educational guideline. It is not a substitute for professional instruction.
More educational skydiving content, as well as this free article, is available by downloading the AXIS Skydiving app on your smart device.
AXIS Skydiving App
“Echoes in Time” Parachutist 75th Anniversary Center Fold
View the digial version of Parachutist’s 75th Anniversary issue.
SKYHOOK Video
Check out our latest YouTube video where we deep dive the differences between a regular RSL (reserve static line) and a Skyhook equipped RSL. Brianne interviews UPT rep/rigger Greg Rau in the AXIS Flight School studio, as well as enjoying a weekend of intensional cutaways.
Greg Rau: “In an emergency there is a lot of other things involved, and the lower you take it, you’re just buttering up your disaster cake.”
Skyhook Deployment Video
I would like to thank UPT‘s Riley Marshall, and Lesley Gale at SkydiveMag for showing off some of my photos and videos in a feature article about the Skyhook (MARD). To learn more about the Main-Assisted Reserve Deployment system, and how it differs from a Reserve Static Line (RSL), check out the full article MARDginal Analysis.
Brianne Thompson cuts away with the Skyhook, filmed by Niklas Daniel over Skydive Arizona, Video by AXIS Flight School.
OEW in the Eloy Enterprise
Disabled veterans learn how to skydive
ELOY — Two paraplegic military veterans have taken up a new hobby and recently began their journey of obtaining their skydiving license.
Ryan Newell and Chris Wolff traveled to SkyVenture Arizona from Kansas and Texas for their first training session with AXIS Flight School instructors Brianne Thompson and Niklas Daniel.
Newell and Wolff are part of Operation Enduring Warrior, which is a veteran-founded nonprofit organization that offers various programs including skydiving.
The skydiving program offers an unparalleled sense of freedom of flight and endless mental, physical and emotional rehabilitative solutions in what can feel like a completely new dimension in their lives, often becoming a lifelong hobby, advocates say.
“The concept I tell my children all the time is society says I can’t do this. I can tell them to sit back and watch what’s about to happen,” Wolff said. “It lets them know and understand that the only person that’s going to change you is you, and the only person to hold you back is you. There’s going to be a time when you find a wall that stops you, but what is it? Is it an equipment issue, is it a strength issue? There’s something that goes on that you can break through, but it’s not going to be maybe the way society thinks it’s suppose to be done and that’s the biggest thing we have to look at.”
Wolff had some previous skydiving experience with four tandem jumps, but Newell had no freefall experience.
At SkyVenture Arizona, the two veterans spent many hours in the wind tunnel learning the basics of how to control their body during freefall.
“It’s amazing,” Newell said. “You’re free. It’s like nothing else in that moment matters, it’s just you and the wind. It’s the most incredible feeling to be in there and be free.”
Wolff pointed out that in the wind tunnel there was a different sense of freedom compared to when he did the tandem jumps.
“You’re defying gravity when you’re in the wind tunnel floating above it, but you’re by yourself; you’re not attached to anybody,” Wolff said. “You’re in control of your turns, your rotations, everything that you’re doing you’re not relying on somebody else. It’s kind of like having training wheels and you kick the training wheels off and you don’t have them anymore.”
Wolff spent 10 years in the Air Force and went to Afghanistan as an aerospace maintenance craftsman to disarm weapons. Everything went smoothly and he returned home, he went through the redeployment line and during the medical portion of the process where he got his vaccines and updates, he got a flu shot.
“Nineteen days later I woke up paralyzed from the neck down from a flu vaccine,” Wolff said. “I laid in a hospital bed for 2½ years as a C5 quadriplegic. All I could do was move my neck side to side, I couldn’t talk, couldn’t function anything on my own.”
Then one day Wolff slightly lifted his arm off the bed and 11 years later he’s able to stand up and walk with forearm crutches.
Newell spent eight years in the Army and was in Afghanistan riding in a Humvee when his accident happened.
“I ended up rolling over 100 pounds of homemade explosives that detonated right underneath the truck and it took my right leg instantly,” Newell said. “It broke my left leg femur in half … I don’t remember anything from that portion of it — just what everybody had told me. I was the only survivor out of the Humvee and that’s actually what drives me to all the stuff that I do, it’s because I live for my teammates.”
Newell and Wolff spent five days in Eloy during the first session of their training before traveling back home. They both enjoyed learning from Thompson and Daniel and pointed out that they enjoyed the experience with their instructors as well as the whole skydiving community in Eloy.
“They take the time and they focus on each individual need and they’ll tell you if you’re doing it wrong,” Newell said. “They had me flying on my own during the first session of being in the tunnel. I’ve talked to three other drop zones and even though they have instructors there, they didn’t want to take the risk of training an amputee and these guys didn’t hesitate one bit. These two just flat out go, it doesn’t matter what the injury is, if it’s amputation or paralysis, they will find ways to make us fly and there’s other drop zones that won’t do that.”
Wolff added that he’s also faced the same obstacles at other drop zones, where they don’t want to take that chance on him.
“In the adaptive world is where we have a lot of roadblocks,” Wolff said. “Finding people that are willing to take what is considered abnormal, but to us is normal life and pushing the limitations of what was considered the norm to this new type of adaptive skydiving, that’s not really adaptive. We’re a skydiver just like everybody else. Adapting is one of the biggest hurdles in trying to find that person that’s willing to just consider.”
Wolff’s end goal is to be able to continue being an example for other people who are trying to break through barriers and to also change the thought process of those who may unintentionally set those barriers. An added bonus is that he has found an activity that he can enjoy with his daughter.
“I always look at what my daughter can do,” Wolff said. “From playing with a soccer ball to riding her bike or something like that and being able to see something that her and I can do together. That my injury isn’t considered the problem of why we can’t do it but the availability to do it or it’s something we have to work together to do. I don’t have to worry about that barrier anymore.”
Newell’s goal is to eventually have enough people go through the training to establish a skydiving demonstration team.
“We want to be able to show not only everybody here in the U.S. but the whole world with a disabled demonstration team,” Newell said. “To show them that we came to AXIS Flight School and they taught us from Day 1, and go all the way to become a demonstration team of wounded warriors or even wounded individuals in general. Show the world, hey. Get out there and do something. It’s not the disability, it’s the ability.”
Behind the AXIS Skydiving APP
Over the past three years, AXIS Flight School has been involved in a joint venture with Good Goblin Games to develop a new kind of skydiving app – AXIS Skydiving, available on Google play and on the Apple App Store. The goal was to create an educational tool/reference manual that covers body-flight and canopy-piloting concepts in a fun and engaging manner. Brianne Thompson and Niklas Daniel are the co-founders of AXIS Flight School and have a history of writing educational articles and creating online video tutorials. Bruce Fournier is a talented animator and app developer and fun jumper at Skydive Arizona. Brianne and Nik are the subject matter experts for the app’s content, providing Bruce with instruction and feedback in creating the animations. The purpose of this app was to develop an innovative way for an audience to visualize movement. From the start, the team wanted to utilize a 3D model. This allows the user to interact with a subject of interest in a way that a picture or video cannot provide. It is important that a user can change viewing angles, time, and use tools that can help visualize the body’s interaction with the relative wind. This led to the creation of Woody, a three-dimensional interactive dummy and AXIS’ new official mascot. Woody offers viewers insight by demonstrating specific maneuvers related to skydiving. In addition, each chapter in the app also comes with a detailed article, photos, and links to tutorial videos. Specific maneuvers are quickly and easily located as they are grouped into categories, such as body-flight orientation and transitions. Brianne puts it simply: “This is the best damn skydiving app in the history of the world.”
Photo by George Hargis
Playing with Ideas
Accomplishing this would have been difficult to do with most standard developer tools. In order to jump over this first hurdle, the team was inspired by video games, as they are specifically designed to display and animate 3D graphics. With a background developing games for mobile devices in his past and still creating game prototypes in his spare time, Bruce understands the potential and power of such an approach. We quickly decided to make the app in a video game engine called “Unity”. This game engine has grown rapidly in the past decade and is used by small indie developers to big name game studios. Although video game engines are rarely used for educational apps, Unity provided all the tools and flexibility needed for the AXIS Skydiving app endeavor to take shape.
Creating Woody
Woody was created and animated in a 3D animation program called “Maya”, which is
Woody flying on his belly.
also used by major video game developers and movie studios. Created entirely from scratch, Bruce did not use any downloadable or royalty free elements. This is where the team decided on what Woody was to look like and any other accompanying gear he might use such as a rig, canopy, and more. Creating the correct and engaging visuals proved challenging. The original idea was to have the app feel like a textbook come to life with Woody jumping off every page. However, the first few drafts were aesthetically boring and uninteresting. After multiple redesigns, the team settled on a look that can be described as stylized minimalism. Through the process of trial and error, the team learned that “less is more”. Avoiding elements that can confuse and distract the viewer, AXIS wants you to see only the bare necessities and what is relevant.
Bringing Woody to Life
After Woody took shape and was finalized with Maya, he was then imported into Unity to breathe life into his movements and appearance. There were some unforeseen challenges in the animating process where the team had to think outside the box. Referencing pictures and videos of a particular action is helpful, however the team had to take a different approach when applying standard animation techniques to skydiving. This is because realism and accuracy of execution is the backbone of the app. Animators typically reference the ground and analyze the position of their subject’s feet. Doing this literally grounds the character and guides the animation process. Woody always being in the air however makes the animation process difficult since there is nothing to ground him in reality and is just one of many hurdles we had to overcome. Bruce: “ Animating Woody was a unique challenge compared to the usual way I animate. Most other animations of a humanoid character I can much more easily reference by physically doing silly things myself like jump, run, and crawl around to get the feel of how something is suppose to look. I just hope no one else is around at the time to watch me make a fool of myself. Pictures and videos of someone else performing the action is always very helpful but this also came with its own problems compared to the usual way I animate. When referencing a picture or video, one of the first things I do is look at the ground and see where the person’s feet are positioned. Having this initial point of origin helps guide many things down the line for the whole animation. For skydiving it is literally not grounded. It also doesn’t help that this is an educational app and the animations in particular have to be accurate. Depending on the project you know you can fudge some things and as long as it looks cool and somewhat believable to the average end user it gets a pass. Big name movies and video games do this all the time. We can look at one of our favorite super heroes Iron Man as an example. It may look really cool when he is flying but in reality he would be crashing into the ground if we think about the real physics of how something is flying.”
Photo by George Hargis
Though Nik and Brianne help Bruce with the animation of movements, Bruce spends most of his time working on the app by himself. Working on the project part time, around five hours per week over three years, Bruce has spent more than seven hundred hours in front of his laptop!
Teaching Woody to Fly
Bruce: “At first I simply tried to read AXIS Flight School’s articles as a guide to the animation and reference pictures as best I could. I am also a novice skydiver compared to someone like Nik and Brianne and figured I could at least have a slight idea in my head how it should look and feel. Long story short, the first batch of animations came out a little sloppy. We later found the best method to make animations is to have Nik and Brianne sit in with me where I do all the technical computer magic and they describe in detail how Woody should look and occasionally Nik or Brianne have to look silly for me to reference from.”
Nik: “It was a fun and challenging process to teach Woody to fly. Since Brianne and I
Woody flying Head-down
coach full time, there was no difference in our approach. AXIS is fully aware that there are many ways to perform a particular maneuver. Models and analogies are always limited in their descriptive power. Choosing a method and focusing on tracking the movements of joints is one effective method of getting a concept across. Of course focusing on joint movement alone is not the whole picture. Timing and body tension are impossible to relay in an image and even video, that is why every chapter in the app has an article to help cover these aspects.”
Brianne: “In order to get the most realistic and accurate representation, Nik and I always started at Woody’s core and worked outward. Since we did not have a net or tunnel walls to reference, we needed to keep a close eye not just on Woody’s body movements, but how he moved through space. Without a reference we frequently used masking tape as a place holder on the monitor we were working on.”
Canopy piloting
In addition to body-flight concepts, the AXIS Skydiving app also features canopy handling drills. As canopy parts and elements are very intricate in nature, AXIS turned to its canopy sponsor Performance Designs. Since accuracy is the backbone of the app, the team wanted to ensure that the depictions and animation of a canopy would be realistic as possible.
Woody under Canopy
PD was able to provide a 3D mesh of one of their products – the Sabre 2. This was instrumentally helpful, but Bruce had to go to work on building a version that could be joined with Woody. Bruce: “Building a functional container with a canopy was one of the most difficult things I ever had to create. There is so many little details and functions that most people don’t realize. There was now three layers of complexity at any given time: 1) Woody by himself, 2) A container that freely moves and morphs accurately on top of Woody along with the function to show if it is open or closed, and 3) Lastly a canopy attached to the container that also functions from real world inputs like pulling your toggles or rear risers. Like the animations before I really couldn’t fudge anything since this was an educational app where accuracy is the most important aspect of the entire project.
The rig I made is a mix of three different rigs. I used several reference pictures of Vectors and Curvs, along with my own Mirage that I closely studied. The first attempt I made at
“Comin’ through!”
building a canopy on the other hand wasn’t bad and in most cases I would have been happy with it and moved on, but again this is an educational app and there were too many small mistakes that a real canopy would not have. A lot of 3D animation work is studying the environment around you that most others don’t notice. It can be a scary though if you have a lot of the basics down of how something is supposed to work but it just isn’t quite coming together.
Just because I have an accurate looking canopy now there was still a lot of work to be done in order to make it work in our app. I first had to delete a lot of geometry. This does make the canopy look a little more blocky with jagged edges, but building stuff for a game is a huge tight rope dance between what will look good and what will actually work with no slow down. The computer or in our case limited mobile devices have to process everything in real time. From there I have to texture the canopy so it isn’t just grey. Then I have to rig it. This means I have to build a skeleton for the canopy and lines. This might sound a little strange but you have to think of how the canopy is going to move and bend for our needs. I place several “bones” that have “joints” and this dictates how the canopy can actually move. After making the skeleton I then make special controls so I can more easily create animations instead of moving one bone at a time.”
Extra Tools
In addition to featuring top-notch animations, the app also includes some useful tools to jumpers of all kinds. Calculators to determine: exit separation, reserve repack cycle, wing loading, and a canopy size orientation guide. Formation skydiving competitors can benefit from an adjustable count down times with audio cue, access to dive pool images, and a performance analyzer.
Moving forward
The AXIS Flight School team is excited to have launched their innovative new app and is looking forward to watching it grow and evolve. As motion-tracking technology is not available to the team, each maneuver that Woody performs is hand animated and requires many dedicated hours of screen time. There are limited copy and paste features available in this work process. This means each animation is created nearly from scratch even as the app is updated with new content on a monthly basis. Bruce: “From developing other projects over the years I have learned that it is best to try and make everything as modular as possible. That way I can take out and plug in just about anything much more easily instead of redoing everything from scratch.”
“Thank you for downloading and subscribing!” – The AXIS Team
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