Two Over One—Responding to Dual Deployments

Tag: Feature, Instructional, March 2012, Safety, Safety Day

Two canopies out.

You’ve got a few ways to get there: Forget to cock your pilot chute so that it flies uselessly behind you and when you dump your reserve, the tension on your main container loosens enough for your main to deploy. You can let too much freefall fun suck you down into the no-fun zone, then deploy your main just as your reserve’s automatic activation device fires. Or you can have a chance encounter with a friend that hopelessly entangles your mains, but when you fire your reserve, everything miraculously clears. Or maybe you can just goof up and pull your handles out of order. But what gets you there won’t be important at that moment. What will matter is that you’ve got two canopies out.

As dramatic as this problem sounds, it’s very rare not to survive a double deployment, and most people don’t even get hurt. It’s probably scarier for the people on the ground to watch, because when you are actually facing the situation, you’ll be pretty busy making decisions and following through.

Dual deployments come in four flavors, presented here in order of both frequency and concern, from least to most.

  • Biplane, where the shorter canopy (the one with shorter lines)—typically the reserve—flies stable directly behind the taller canopy.
  • Side-by-side, where the two canopies fly stable, end-cell to end-cell, to resemble one very wide canopy. One canopy will be dominant, that is, fly more nearly overhead.
  • Downplane, where the two canopies try to fly away from each other as they dive or pinwheel toward the ground.
  • Main-reserve entanglement. Good luck.

Each of these has its own procedures and controversies, and even the last one isn’t hopeless. As with most skydiving scenarios, the situations require a jumper to have given them enough thought on the ground to have a solid plan in place. Frequent review and practice increase the likelihood that a jumper will execute the plan correctly when the situation comes up—rather than make things up on the spot. History has shown that people are not very good at improvising during the excitement of skydiving emergencies.

What We Know

Much of what we know about dual deployments (and most of what this article is based on) comes from studies done in the 1990s. The U.S. Army Parachute Team and—independently—USPA Instructor Scott Smith reported on live jump testing involving approximately 30 intentional dual deployments. Canopy manufacturer Performance Designs (PD) gathered this information from them and followed it up with a series of 48 more jumps. PD published its findings under the title “Dual-Square Report.” PD presented the report to the Parachute Industry Association in 1997, and PIA adopted it. PIA has published the report on its website as PIA Technical Bulletin TSB 261. It contains good, digestible information for skydivers of almost any level.

The testing was performed under relatively large canopies, with mains down to about 135 square feet and a variety of reserves. According to the PIA report, research from all three studies led to approximately the same conclusions. And, according to PD Vice President John LeBlanc, the company has made more jumps since the PIA report and has not changed its conclusions.

The PIA report and the recommendations in Section 5-1 of the USPA Skydiver’s Information Manual (SIM) set a good starting point for a jumper wishing to develop a set of procedures, at least for less-aggressive canopies. At this time, nothing comprehensive exists on cross-braced and other high-aspect-ratio, zippy mains. (Who wants to do those tests?) However, a lot of anecdotal evidence suggests that they don’t follow the same rules as larger canopies when sharing space with a reserve—particularly when not closely paired as far as size and performance capabilities.

What's It Gonna Be?

What the PIA report found was that knowing the height (line lengths) of your main and reserve may help to predict how they’re going to behave together, although the information is mostly academic compared to how you’ll handle the actual results if the time comes. But if you’re interested, manufacturers often publish the line lengths of their products in the owner’s manual. You can also ask your rigger to measure them. A reserve typically has shorter lines than a main of the same square footage, and the front lines of any ram-air parachute are shorter than the back lines.

Generally, if the lines of your main are longer than the lines of your reserve—or more specifically, the leading edge of your reserve opens lower than the trailing edge of your main—and your main opens first, expect a biplane with the main in front. If your reserve opens first, expect a side-by-side.

If the opposite is true—the leading edge of your main is lower than the trailing edge of your reserve and your reserve opens first—expect a biplane with the main behind. If your main opens first, expect a side-by-side.

However, predicting which canopy will become dominant is trickier, and you won’t really know until you actually see it. (“Dominant” for the purposes of a side-by-side means the canopy that is more directly overhead.) You can use the chart below as a predictor, but know that results may vary and that you’ll need to respond to what you actually have if you find yourself in a two-canopies-out situation.

Opening with line twists on one of the canopies may result in a side-by-side or a downplane. You might also get a downplane, or at least a lot of instability, if the two canopies differ greatly in size and in their performance capabilities. With canopies that are greatly mismatched in size and performance, the bigger one may take so much of the load that the smaller one has trouble even staying inflated—meaning that it is likely to become very unruly.

Bear in mind that these results were observed after only 100 or so test jumps and without studying every combination of main and reserve. Responding correctly to the outcome is more important than predicting it.

Predicting Dual Deployments Main bigger/taller than reserve Reserve bigger/taller than main Line twist or great size difference
Main opens first Biplane, main in front Side-by-side, reserve dominant Downplane possible
Reserve opens first Side-by-side, main dominant Biplane, reserve in front Downplane possible

Whatcha Gonna Do?

feature20123-31
Anatomy of a two-out malfunction: An A-licensed skydiver with about 35 jumps lost altitude awareness during a 2-way jump and pulled low. The automatic activation device armed and fired just as the jumper's main canopy fully deployed. The jumper landed under both canopies in a stable bi-plane configuration. Photos by Brian Marcus.

Fortunately, dual deployments have a number of effective remedies. The best is prevention.

Maintain your equipment, particularly your pilot chute and automatic activation device. Pack conscientiously, never neglecting to cock or re-set your pilot chute. Get a gear check, especially your main pilot chute bridle (to make sure it’s cocked) and reserve pin. Plan, practice and perform your exit carefully enough to miss hitting or snagging your equipment on the door, wheel, strut, etc., on the way out. Open high enough to deal with problems before you reach AAD-activation altitude. Inspect yourself and your equipment thoroughly after any kind of a collision or unusual event. (Jumpers have landed with partial secondary deployments without even knowing it. And you really don’t want to initiate that big 270-degree turn to final with your reserve pilot chute—which could easily lead to a full deployment—trailing in the breeze.) After you open, fly a predictable pattern with your head on a swivel all the way to landing to prevent having to pull your reserve after a low-altitude collision.

How to deal with two canopies out has generated lots of debate. Some remedies certainly merit review and discussion, but the sport has observed enough to draw some solid conclusions.

Except for entanglements, a given pair of open canopies will seek one of the three configurations: biplane, side-by-side or downplane. The SIM wisely advises, “Trying to force one configuration into a more manageable configuration is typically futile and can be dangerous.” For example, flying a downplane into a side-by-side might stabilize things temporarily but may not allow for a safe landing. It may also be possible to separate a biplane into a side-by-side and execute a successful cutaway; however, the canopies will try to re-form into a biplane as soon as you take your hands off the controls to take an action like pulling the cutaway handle.

Just about everyone seems to agree that:

  • Cutting away with the canopies in a biplane configuration is dangerous, because the departing main can easily entangle with the reserve.
  • Cutting away from a stable side-by-side is an option but not without its risks. This includes flying a biplane into a side-by-side and cutting away.
  • Cutting away from a downplane is essential.

Biplane—Keeping what the PIA report calls a “personal biplane” and landing with it has been the conventional wisdom since the late 1990s when the SIM first recommended in Section 5-1, Skydiving Emergencies, as follows:

“a. Unstow the brakes on the front canopy and recover gently to full flight.
b. Leave the brakes stowed on the rear canopy.
c. Steer the front canopy only as necessary to maneuver for a safe landing.
d.Use minimal control input as necessary for landing.
e. Perform a parachute landing fall.”

Despite this recommendation, manipulating a biplane into a side-by-side to enable a cutaway has since surfaced as an option, particularly for some military and government training programs. Keep in mind that Department of Defense and government training generally take place in a more structured environment than the typical weekend first-jump course and may focus on different objectives. Plus, military operations typically involve large, docile canopies matched together as a complete system.

For those jumpers who do decide to cut away from a biplane, it makes sense to split the main to the left so you can hold it there with its left-side controls and cut away with your right hand. The main will depart violently, so move your hands free of the departing risers and lines. But you can’t just fly into the side-by-side, let go and cut away. PD’s LeBlanc said it surprised him how quickly a manually split biplane wants to return to the biplane configuration, even with moderately sized canopies. “It comes back really quickly,” he remarked.

For most people, it is best to fly the biplane as it is. The PIA report states the case well:

“It does not make any sense to take a docile, maneuverable and landable biplane configuration and try to change it.” LeBlanc adds that the PD tests all took place from 8,000 feet with at least a third and sometimes a fourth back-up parachute. He cautions against heroic or complicated responses that may sound good on the ground but don’t make sense in the reality of a two-canopies-out emergency. You’re low, and as he says, “You weren’t paying attention to begin with or you wouldn’t be in the process of screwing up.”

feature20123-32This jumper is landing a side-by-side that resulted when his nearly new reserve closing loop broke at the grommet while he was flying his main (indicating that the grommet may have had a rough spot that abraded the loop, causing it to fail). The brakes appear to be set on both canopies, and the jumper is using the rear risers of the dominant canopy (the main, in this case) to steer. While this isn't the SIM recommendation (release brakes on the dominant canopy, steer with toggles, don't flare), test jumper John LeBlanc from Performance Designs reports good success with this method and a good PLF. Photo by Harry Parker.

Side-by-side—The SIM recognizes that either cutting away or landing might be a reasonable choice with a side-by-side. As usual with skydiving decisions, choose early and execute your decision without delay. According to the SIM:

“Side-by-side procedure 1:
If both canopies are flying without interference or possibility of entanglement and altitude permits:
(1) Disconnect the RSL [reserve static line].
(2) Cut away the main and steer the reserve to a normal landing.

Side-by-side procedure 2:
Land both canopies.
(1) Release the brakes of the dominant canopy (larger and more overhead) and steer gently with the toggles.
(2) Land without flaring and perform a parachute landing fall.”

feature20123-33After partially dislodging his reserve pin on exit and experiencing a dual deployment at pull time, this low-time jumper struggles with a side-by-side. He has mistakenly caused the canopies to start splitting into a downplane just as he lands, probably due to applying input while having one hand on the left rear riser of the reserve and the other on the right rear riser of the main. By this point, he should be preparing for a PLF. Photo by Craig Goodman.

 

 

 

 

If you’re looking up at two good parachutes that seem to be getting along, you may not want to chance cutting one of them away. If you decide to land it, you don’t want to make any radical movements—steering the dominant canopy away from the other might cause them to separate temporarily, and turning it inward might cause a minor scuffle. Small movements on the controls work best, especially close to the ground.

Given enough altitude and if everything looks like it will clear easily, disconnecting the RSL and cutting away might appear to make sense, too. However, as LeBlanc succinctly puts it, “[A side-by-side] is a flyable situation, and an entanglement is not.” He also points out that it’s virtually impossible even for an expert to inspect the situation and be 100 percent sure that one canopy hasn’t opened through the lines of another and will clear when released.

Downplane—Nobody’s going to argue: Cut it away. If there’s time to snag the tag to disconnect the RSL first, then do it.

Why Disconnect the RSL?

Jumping with an RSL, including the Skyhook RSL, comes with a few trade-offs. RSLs should integrate seamlessly into routine cutaway or total malfunction procedures, but jumpers should consider them when dealing with two canopies out. Regardless of the configuration, all RSLs attach to the main riser on at least one side. In the event of a cutaway following reserve deployment, a still-attached RSL forms a pigtail at the end of the main riser with the potential to wrap around something such as the reserve ripcord, the RSL’s guide rings, a reserve riser or a camera mount. If the reserve ripcord wasn’t extracted (e.g., the AAD activated), cutting away from a side-by-side with the RSL still attached causes even more potential problems.

In reality, few reports of RSL entanglements following a two-canopy scenario have emerged. That’s why the RSL becomes a secondary consideration when getting ready to cut away. If there’s time, altitude and brain space available to keep it from interfering with more important responses, then it’s best to disconnect the RSL at the clip before cutting away. If your RSL has two ends to unclip, one on each riser (at least two systems use this method), disconnect both.

Partial Deployments and Entanglements

If you have one parachute open and the pilot chute of the other has deployed, you need to act quickly but calmly. If you can, don’t release the brakes until you contain the unopened parachute, but keep track of altitude so you can flare normally for landing. If the reserve’s open and the main pilot chute has deployed, cut away first, release the RSL if time permits, and clear the risers from the three-ring system before trying to retrieve anything.

Whether it’s the main or reserve, retrieve the pilot chute gently to prevent whatever’s keeping the deployment bag in the container from breaking loose. Get control of the pilot chute and grip the bridle as close to the deployment bag as practical without jerking it loose.

If the main or reserve deployment bag escapes from its container with the other parachute already open, altitude may no longer be your friend. Trying to retrieve or contain the deploying parachute might lead to problems (it’s really hard to do). Allowing it to deploy may lead to other problems. You must keep track of altitude and evaluate your options as the situation develops.

An entanglement between the main and reserve can run the gamut from annoying to—let’s face it—deadly. It helps to have made some wise choices before you ever get there. Fly parachutes big enough to provide some safety margin in less-than-ideal circumstances. Match them closely in size and performance. Choose a different color for your main and reserve. Know the colors of your main and reserve toggles. Don’t cut away your main until you’re sure it’s not doing you any good or if it’s clearly making the situation worse. Keep as much nylon overhead as you can.

Ram-airs get frisky when partially inflated, so if the advice in the SIM (“attempt to clear the problem by retrieving the less-inflated canopy”) fails to improve the situation, work to improve what you do have overhead: if you have some inflated cells that you can improve on or stabilize, work with that. Pumping the brakes may shake things loose. Or simply use the brakes to slow things down. Even settling on a slow turn might get you to where a PLF is effective to prevent or minimize any injuries. Never give up.

Keep It Simple

Be wary of alternative procedures that have succeeded for a particular jumper unless you understand the entire scenario he experienced. You have to account for how many jumps and what kind of experience he had (e.g., has he flown lots of canopy formations?), which canopies he flew, his overall risk-taking attitude and the circumstances of the incident. For most of us, having a simple set of easy-to-execute, stimulus-response procedures for the majority of two-canopies-out emergencies (that we hope to prevent and never encounter) should serve us best.

For all the fear they conjure, dual deployments don’t happen that frequently and can, for the most part, be prevented. Plan your procedure for each eventuality before getting in the plane—a procedure that makes the most sense for your equipment, experience and any of the number of variables that apply to your style, frequency and location of skydiving.

Until the day when skydiving parachutes become 100 percent reliable and we can jump safely and legally with only one, skydivers will have to negotiate the possibilities of two canopies out.

Special thanks to John LeBLanc, who contributed heavily to this article and who, along with Joe Stanley, Rusty Vest and others, executed many of the jumps for PIA’s “Dual-Square Report.”

About the Author
FEATURE20119-10 Kevin Gibson, D-6943, earned his FAA Master Rigger rating in 1985. He is a former editor of Parachutist and a former USPA Board member. A professional skydiving instructor with 9,000 skydives, Kevin also operates Rahlmo's Rigging in Orange, Virginia, and continues to support USPA and Parachutist.

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Wally Hockenbury
Sun, 04/08/2012 - 10:03

I don't really have a comment but i have a question. If you try to split a bi-plane into a side by side what are the chances of the reserve going in front of the main if when the canopies come together causing an entanglement? Is there any records of this ever occuring?

Thank You,
Wally Hockenbury

Greg Barich
Thu, 05/10/2012 - 00:47

Thank you for all this info. I,m new to the sport and can,t review enough about emergency procedures. I want to be as informed as I can and your article really helps. Again thank you.

SkyMarkyMarkD
Mon, 08/13/2012 - 13:02

Awesome article, thanks!

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