THINKING about Wingsuit Openings
Andy Farrington, backflying the Squirrel C2. All 'competent' WS pilots can backfly. — by Matt Gerdes
Flying a wingsuit, if you’re ready, is pretty straightforward. It doesn’t take much effort: just relax, look where you want to go and fly it back without hitting anything. The tricky part – that even some highly experienced skydivers still struggle with – is the deployment of your parachute.
We at Squirrel seek to improve wingsuit design & technique. The success of our products is thanks to our extensive stable of test pilots who have worked hard to elevate techniques just as much as product performance.
This article is an attempt to collate some of what we have learned from the only collaborative effort to test wingsuits & parachutes. This is what we think works best now, in 2016 & it may contradict some older instructional material that we consider outdated. The techniques here will, hopefully, eventually, be replaced by better techniques. Such is the nature of progress. Out with the old, in with the new!
The “pull” is the beginning of a process, not the end
The most common mistake is to stop flying or controlling one’s wingsuit & body once the BOC reach begins. Reaching for the pilot chute & deploying it is the beginning of a process that needs your full & active participation.
First & foremost, fly your body & your suit symmetrically through the entire deployment process. Whether you collapse everything or nothing, you need to do it symmetrically, so you have to maintain an awareness of your actions. Pitching out your PC & then going limp or just thinking “it’s over now” will not work. We see people “give up” on maintaining their heading, pitch control & suit symmetry the moment they begin to reach for their BOC. This could be the one moment of the flight where symmetry is most important.
Concentrate on keeping your shoulders level & perpendicular to your line of flight. Choose a marker on the horizon & maintain your heading directly towards it. Once your risers begin to load, keep the load equal by reacting to the feedback transmitted from your opening parachute.
Throw your PC like you mean it
We know from countless rear-facing WS BASE camera angles that a weak toss & slow flight can render a pilot chute completely useless if it is sucked onto your back or leg wing. To prevent this, reach back symmetrically (most pilots reach back with both hands, to keep arm wings symmetrical) & deploy symmetrically, with enthusiasm & gusto. A wildly aggressive pull will negatively affect your body position, so keep it under control.
Deploy your PC with the clear & unwavering intent to get it into the clean air that is well to the side of your wingsuit. Never drop it & never half-pull or half-ass this process.
Think symmetry, not just for your body, but also for the airflow behind you
At 100mph, even your hand creates a significant & long-lasting wake. The surface of one of your arm wings is considerably more influential. By making your two arm wings even slightly asymmetric, you can create an impressive amount of swirl in the turbulence behind you, which is guaranteed to affect your pilot chute & canopy as they begin to inflate. Symmetry is not just important for the loading of your harness, it’s also critical to the airflow that feeds the inflation of your PC & parachute.
Obviously, while your asymmetric position is disturbing the airflow, it is also changing your heading. A heading change during deployment will not help your opening.
Symmetrical PC Deployment
Avoid habits that will ruin you in Wingsuit BASE, if you’d like to go there someday
If you never plan to BASE jump & you never intend to jump a higher performance wingsuit, no matter what, then you can crumple yourself up into a cannonball & lose 1000’ of altitude before every deployment if that’s what you like (as long as it’s a symmetrical cannonball). But, if you think you maybe one day want to try wingsuit BASE, or might want to jump a more advanced wingsuit, then let’s start smart & develop the proper muscle memory now.
This means deploying from a flying position. If not full flight, then at least close to it. Collapsing leg & arm wings causes an immediate, significant loss of altitude. It also takes time. It also encourages asymmetries. Losing a bunch of altitude & time on creating an asymmetric position will never be a positive thing for you in the BASE environment.
Your first wingsuit BASE jumps will be made on a moderate- to small-surface wingsuit, which will not be capable of a powerful, efficient flare. When BASE jumping smaller intermediate wingsuits, it is very important to maintain speed & glide while deploying. Do not slow down to minimum-sink before pitching. Keep clean air flowing over the top surface of your suit & maintain forward flight during deployment. Fly efficiently, fly forward & collapse nothing.
One day, when you are jumping a more advanced wingsuit, you’ll be able to flare up & gain 100+ feet, do a barrel roll, smile at your belly camera & then deploy however you want. But save the silliness for later.
Symmetrical reach (skydive) — by Lesley Gale
Do you ever plan to jump a larger more advanced wingsuit?
If you’re going to grow your wings someday, then developing a dependence on wing collapse for deployment is not the best plan. Five years ago, most wingsuits could be collapsed with only moderate effort, even the largest designs. Things have changed & today that is not the case. Modern higher performance suits have higher internal pressure, higher trim speeds & more leading edge structure. All of these things recommend a full-flight or near full-flight deployment.
A full-flight deployment can be applied to any suit. Learning it early – although maybe not in your very first month of training – is a good idea for pilots who intend to progress further.
That being said, the beauty of modern wingsuit designs is the wide speed ranges that are possible. Varying airspeed & pitch changes internal pressure & makes it easier/harder to collapse & pitch. Because of the wide range of speeds, we have a wide range of deployment technique options. In a larger design, if you want to flare, reduce airspeed & crumple it up, you can!
Today, most advanced pilots do not collapse their wings. There are lots of options, but the factors that form the basis of a full flight deployment are:
Full Flight Deployment Factors
See fig 1. By reducing your sink rate & increasing your glide (flaring) at a reasonable airspeed (not too slow), you can create a minimum of wake turbulence (burble).
Don’t deploy in a stall, or at a steep angle.
Reach around the top surface of your arm wings, “squeezing” as little air as possible out of them. The path to your BOC is not through the wing. The path to your BOC is around the top surface of the wing. Practice this on the ground with a blower inflating your suit & do hundreds of practice touches during skydives. The muscle memory needed to rotate your wrist properly & reach around the top surface of your arm wing, with your hand going directly to your PC, requires training.
Any pull technique that involves squeezing/collapsing your arm wings or touching anything other than your PC handle before finding your PC handle, should be improved.
The entire process from thought-initiation to PC release should take about 1 second. Train this movement until you know for certain that you can go from normal flight to PC release in 1 second. Your hand should pass over the top surface of your wingsuit, go directly to your PC, which should be released into the clean airstream well to your side, before one second is up.
Remember that there is a 0% chance that your skydive BOC & BASE BOC are located in the same place. This means, if you apply the same motion to your BASE rig that you’ve been using on your skydive rig & miss your PC, you could die. It has happened. Practice touches are important on BASE jumps too. Ensuring your equipment fits well & is properly configured is also critical. Finally, leaving yourself altitude margin to be imperfect, as we all are, is critical.
These are basic guidelines that you can use to develop your own technique. Don’t listen to anyone who tells you there is only one way to do it, because there isn’t. Keep your mind & options, open.
Airspeed: Not too fast, not too slow. Keep it efficient, keep it clean
The beauty of wingsuit parachute deployments is, you have a lot of control over your airspeed. If you want a more aggressive parachute opening, you can fly steeper & faster. If you want to tow your PC for a while, then you can slow way down. Happiness is a speed somewhere in the middle. We must also deploy into the cleanest possible air; to do so, we need to manage our burble.
Burble management is secondary to airspeed management. First, adjust your airspeed. You will learn very quickly what makes you go fast/slow in your wingsuit & what airspeed works best for deployment. Next, you need to arrive at that airspeed with the correct Angle of Attack (AoA), this provides a clean airflow over the top surface of your suit.
The process is: Fast or normal full flight, then slow-down (brief flare), then level off until you feel air flowing cleanly over the top surface of your suit, then deploy symmetrically.
Fig 1: controlling your pitch and airspeed before a full flight deployment
Equipment: Bridle length, PC size, D-bags, packing
Bridle length: Longer is not better. Around eight feet from pin to PC is adequate.
PC size: For skydiving, a ZP PC in the 28-30” range is the commonly accepted norm.
D-bags: Many jumpers feel that stowless d-bags yield smoother openings. I myself am a huge fan of them for wingsuit applications.
Packing: A typical skydive deployment without wingsuit sees your PC, bridle, D-bag & parachute lines extended above you in a vertical chain. The chain of deployment occurs more vertically. When you are flying a wingsuit, the deployment is spread out more horizontally.
This more horizontal deployment chain is sensitive to many factors; your burble, the efficacy of your PC, how you stow your lines, your d-bag design & how you pack.
The more time that your parachute system is elongated in this horizontal configuration, the more opportunity it has to get weird. Once your parachute begins to emerge from the d-bag, your PC is being killed. At that moment, your uninflated parachute is like a like a tumor on a jump-rope & your burble is causing it to dance around like an epileptic lizard.
A more horizontal deployment chain
Leaving an open channel & rolling tail lightly gives earlier expansion, reducing twists
Often, at that stage where your parachute lines are extended, your PC is killed, but your parachute has not yet begun to inflate, line twists occur. The more time you allow your parachute to dance & twist in this position, the more line twists you will have.
The solution is very simple: minimize the amount of time that your parachute spends uninflated, dancing around at line stretch. To do this, one option is to not roll the “tail” (trailing edge) of your parachute so tightly around your lines. The technique of rolling the tail tightly around the lines was not developed & should probably not be used, for wingsuits.
Leaving an open channel here & rolling the folds together lightly, just 2-3 times, encourages earlier parachute expansion once your packjob reaches line stretch. The sooner it expands, the less time it has to twist & twirl & the fewer line twists you’ll have.
What’s that you say? If you pack like this, you’ll get “slammed”? When you are jumping a wingsuit, you control your airspeed destiny. Pack for the type of jump that you are doing. Fly for the type of opening you want.
What’s that you say? If you collapse all of your wings & drop like a stone, it eliminates the horizontal nature of the deployment? The problem with this is that most intermediate-advanced wingsuit designs cannot be easily or effectively collapsed before deployment – at least not without a huge flare & associated reduction of airspeed & therefore internal pressure.
If the thought of packing this way scares you, or you think it’s a bad idea, then don’t do it. All we can do is offer what has proven to work for us when flying high performance wingsuits.
Twists: Why they happen, how to avoid them, how to get out of them
There are two types of line twists:
1, Line Twists
2, Body Twists.
Line twists occur during extraction of your packjob, behind you, out of sight. You will only know you have them once your parachute begins to inflate & you feel your risers a bit too close together, angling in above your head (you can feel this if you jump a wingsuit that allows early riser access without cutting away or unzipping arms). These twists are the result of packing & asymmetries discussed above. To prevent them, work on your packing & wing symmetry at deployment.
Body twists occur at your body & are caused by you rotating underneath an inflating or flying parachute. These are extra stressful because sometimes they can be hard to stop & often result in the highest number of rotations.
The best way to end up with a whole bunch of body twists is to deploy in a slight turn, load your inside riser by dipping that shoulder & then have a hard or violent opening. As your parachute inflates, you are inputting a turn with your shoulder. There is no harness design that can prevent this shoulder-input, regardless of what gimmicks you might have seen. As that turn continues during the opening, your body may begin to rotate on the single axis point of one riser. Once the rotation momentum begins, it can be difficult to stop. An abrupt or violent opening can aggravate this & the worst body twists in wingsuit BASE invariably occur during harder openings.
Body twists can be prevented or discouraged with riser control. The moment that your parachute loads & begins to sit you upright, your hands should be on your risers. Steer your parachute via the risers, maintaining your forward-facing body position via the risers & holding them apart, if necessary. This helps to keep you facing forward, on heading.
To reach your risers wearing a wingsuit:
1. Deploy your PC
2. Immediately punch your fists straight forward
3. Then reach up & grab your risers.
Holding your risers apart will help to stop body rotation & you will be able to control your canopy.
Note it’s possible to overdo this. If you reach up & crank your risers apart early & hard and there are packjob-induced line twists occurring, then you may cause the twists to happen higher in your lines, exacerbating the situation. Moderation & sensitivity are key.
Jumping a wingsuit that allows you to manipulate at least the bottom section of your risers without unzipping or cutting away is very important.
Once you’re in twists – it happens to us all – there are several solutions. Cutaway decisions are always best when not made late.
Remember that your first priority is heading control. Heading first! Before worrying about the twists, be certain that you’re not about to hit anything. If you need to climb above the twists to change heading, give weight shift input, or even release a brake to prevent a collision, do it. Then deal with the twists.
Your first priority (before the twists) is to make sure you're not going to hit anything — by Mick Knutson
I am not attached to any single “untwist” solution & I am certain that there are other techniques that may work as well/better than the following options listed in the order I normally attempt:
1, Grab risers/lines & twist yourself out. Look up, see which way you need to untwist & manually turn your body under the parachute like you’re wringing out a towel with a friend. Some people say push risers together & do this, some say pull them apart. I generally try to push together & twist.
2, Stick one arm wing out into the airflow & use it to “windmill” your way around. You have to do it on the correct side & you have to have an arm wing big enough to catch air & influence the turn. If you are unconsciously sabotaging yourself with an asymmetric leg wing at the same time in the opposite direction, this will be less effective! Your leg wing also provides resistance in the right/wrong direction.
3, Kick & scream. Some say this works. The kicking part may be most effective.
Another preventative cure for body twists is maintaining a symmetric body position. If you deploy your PC in a slight turn, you will be hanging more from one riser, which then becomes a pivot point. This is a problem on every harness ever made; the solution is symmetry & riser control.
Hard openings tend to deliver the most violent body twists. You control the opening force with AIRSPEED. In a wingsuit, you choose your airspeed. You can choose fast/slow, up/down, horizontal/vertical, etc. Find what works best for you & then consciously choose it. Do not just pitch your PC without thinking about what airspeed & angle you want to have for deployment.
Twist Sidenote – NB!!
If you are jumping anything other than an absolutely tiny beginner wingsuit, it is probably a BAD IDEA to unzip your leg wing while in twists. The result is that the leg wing trails behind you like a weather vane. Because of your airspeed, this weather vane will make it very hard for you to rotate under your canopy & untwist. If you then cutaway, and your reserve opens in line twists, as they sometimes do, you will once again have the same weather vane problem. This situation badly injured a good friend of mine (he landed very hard under a turning reserve, in line twists). Consider keeping your leg wing zipped up until you’re under a good parachute.
Parachute type: Go lightweight, low bulk, “F-111” & docile
It has long been known that 0-3cfm material (F-111) yields better openings than ZP. The porosity of 0-3cfm fabric delivers more consistent, predictable inflation.
ZP fabric is popular in skydiving because it is very durable, and we skydivers have been known to be a little cheap. While it would be nice if our equipment lasted for eternity, the quality of your openings should mean more than getting a few extra jumps out of your parachute. Wingsuit specific F-111 canopies have proven to open better & lead to fewer cutaways. When flying a wingsuit, the most critical moment is usually the opening.
Regardless of the fabric your parachute is made from, a docile, 7-cell, low aspect ratio design should be considered mandatory. A lightly loaded size “larger-than-you-normally-would”, is best. There has been some discussion on whether sizes smaller than ~120sqft may have line sets which are short enough for the parachute to be sucked back into your burble during deployment. If you think it sucks to have that happen to your PC, wait until your parachute does it. The other day I watched a friend “streamering” head-down under his 109sqft 9-cell ZP design, his lines tangled in a smoke bracket on his left foot. He cleared them by hand & didn’t die, which was awesome. I am pretty sure it was the last wingsuit jump he’ll ever put on that thing, though it was probably fun to land.
Pull high! Don’t let a docile parachute make you overconfident
Once you have a docile, F-111, lightweight wingsuit parachute, you’ll probably get used to it very quickly. The comparatively wonderful openings will give you confidence & make you happy. And the best way to fuck up your happiness is to start pulling lower.
All parachutes, regardless of their design, track record, your packing technique or your skill, can & will eventually malfunction. Line twists are practically unavoidable with wingsuits & the probability of malfunctions may be increased. Give yourself time & altitude to deal with the drama.
Fly efficiently before and during pull time, maintain awareness through the deployment process and fly your body symmetrically, know how to reach your BOC cleanly and quickly, control your risers, and use the right equipment. Have fun