CReW wraps..

[darkvapor 0]

Never done CReW. But I'm just curious: How easy or difficult is it to clear a wrap? It is my understanding that several individuals died last year from a wrap. Is it not a huge deal, where you can just push your way out of the mess and execute emergency procedures? Do you think it is the most dangerous aspect of CRW (more dangerous than say, the risk of a collision in freefall?)? Have you been in a wrap that had you thinking you were in serious trouble? Other comments and related topics will be appreciated.

[crwmike 0]

Wraps are usually not difficult to clear, you can usually pull them off or 'swim' your way out of them.

Entanglements are a bit more tricky. When you see someone (or several someones :) coming around at you there are two schools of thought.

1) Curl up in a ball, hoping you'r smaller surface area will go completely through lines (resulting in an entanglement which you both have to cut away from).

2) Spread your arms and legs WIDE (my choice, unless it a body coming at me). Then you stop the canopy/lines from engulfing you and must throw it clear.

Mike Lewis wrote an excellent paper on emergency procedures and I'll include it in this response. This paper, and more on CRW safety and training) are maintained on Wendy's site. The articles are required reading for anyone invited to the 2003 CRW World Record attempts.

http://crw.boxofclue.com/skydive/crw.html

-------------

CRW Emergency Procedures by Mike Lewis

The first step towards solving an emergency situation is to have a plan.
It must be a good plan gleaned from the wisdom of experts. You should have
only one plan for each possible situation.
The second step is to practice it. You should practice your emergency
procedures so that you know them. An emergency is not the time to be confused
or indecisive. The best time to review emergency procedures is whenever that
natural fear of being out of control starts to creep in. This will replace
the negative fear with a positive plan, and the plan will be the first thing
that comes to mind in an emergency situation -- not the panic.
The third step is to do it! An emergency is not the time to get
creative and try something that wasn't thought out during a less stressful
period. In other words, stick with your planned emergency procedures. CRW
emergencies can be divided into two categories, i.e. wraps and
entanglements. A wrap is when a parachute is wrapped around a jumpers
body. An entanglement is when the parachutes are entangled with each other.

WRAPS

A wrap is similar to a low speed malfunction. The top jumpers parachute
will remain open. This gives you more time to deal with a problem than
you would have with a freefall emergency. You do not want to land a
modern square parachute with two people under it. You may have incredible
forward speed because ofthe increased wing loading· The general rule for
wraps is that the bottom jumper cuts away first. The top parachute
usually remains open, so there is no reason to release it. Also, if the
jumper who has the parachute around him cuts away (the top jumper), he
will go into freefall with the bottom jumper's canopy wrapped around
him. That will only make matters worse. Usually you can climb out of a
parachute by sliding the material down your body. If not, then the
bottom jumper cuts away. That will release the tension and make it easier
to climb out of the fabric.

ENTANGLEMENTS

An entanglement usually results from one jumper passing through the lines
of another jumper's canopy. This causes the two parachutes to be entangled,
with the pilots dangling beneath them. This situation almost always requires
both jumpers to cut away. Usually one person will be suspended higher than
the other. The general rule for entanglements is the top person goes first.
If the bottom jumper releases, his lines and risers may recoil upward and
wrap the other person. When the top person releases first, he may bounce
off the bottom person on the way by, but he won't have much momentum.
The top jumper usually is the one who passed through the lines,
and many times his parachute will pull itself out of the mess after being
released. This is a bonus for the bottom jumper.
Sometimes the entanglement will start spinning, with one jumper
hanging downward and the other one orbiting the entanglement. In this
situation the orbiter should cut away first. This will fling the
orbiter clear of the entanglement without changing the other jumper's
orientation. If the jumper hanging downward releases first, it will change the
orbiter' orientation to the mess and could make his situation worse.


COMMUNICATION

When involved in a wrap or entanglement the first thing to do is to
communicate with each other. You need to communicate the altitude, the
problem and the plan of action.
When someone has a parachute wrapped around him, he may not be
able to read his altimeter. In all the excitement, he'll probably
forget his last altitude reading, and you don't want him to panic and
cutaway. When you are totally engulfed in nylon, it is very reassuring
to hear the altitude called out every 500 feet. It also helps to hear
that your parachute is okay and if "you crawl to the left" it will come
loose, or some similar instruction. If you cannot get any response from
the person wrapped up in your canopy you should go ahead and cutaway.
The jumper probably has nylon around his face or neck and you need to
release the tension by releasing your risers.
If you are the one who is wrapped in parachute you should communicate
that you are working on the situation. Speak to the other jumper at regular
intervals. "Don't cut away" is the wrong thing to say as the other jumper
might only hear the last part and jettison his canopy.
Once the decision to cut away has been made, you don't want to panic.
First get your hands on both handles and check that you are clear of
any lines. You should peel the cut away handle off the velcro, but leave
the reserve handle in its pocket. If you have a hard pull on the cutaway
handle you can release the reserve handle and use both hands to cut away.
Keep your eyes on the reserve handle so you can grab it quickly. Be
ready to make a freefall delay if you have sufficient altitude. If more than
one person is going to cut away, the first one out needs to freefall
for five to 10 seconds. This will allow sufficient vertical separation for
the next person to open a reserve.
The foremost thing we can do to keep a margin of safety is to respect
the altitude. Most problems start during docking or break-off.
USPA says the limit for docking is 2500 feet. The real question is
"How low do I want to be in a wrap?" The next question is "How low do I
want to be in freefall" USPA says the decision to cut away should be made
by 1800 feet and the procedure started by 1600 feet. These limits were
determined by years of experience and should be respected.
I do not recommend that you cut away below 500 feet. At that altitude
you should save yourself by deploying your reserve without breaking away.
It is better to add more nylon to the mess than to accelerate towards
the ground at such a low altitude.

DOCKING

What causes wraps and entanglements? Most are caused by bad docks. The
three factors most often involved are speed. angle and distance from the
center.
If you have too much speed your body continues to travel after you
have docked. The point where your canopy has been gripped remains stationary,
but the rest of the canopy continues to move in the direction your body
is traveling. if you warp the parachute too much it wil lose pressurization
and wrap the other jumper you are docked on. Because things tend to swing in
an arc, it is common for the parachute to wrap securely around the other
jumper.
There are good and bad docking angles. A straight in aproach,
directly behind a jumper at zero degrees is the safest. Docking head on, or
180 degrees, is obviously the worst angle. Docking with your parachute
at 90 degrees relative to the other jumper's heading will still give you too
much speed. The most efficient angle is at 45 degrees relative to the other
jumper. Docking with an end cell is more likely to cause a wrap than docking
with a center cell. These factors combine to make a dock safe or unsafe.


FORMATION FUNNELS

Another cause of wraps and entanglements is when the formation
funnels. This can be the result of a mismatched or "misflown" canopy that
is collapsing. it can also be caused by a stalling canopy.
In a planed formation the nose of the parachute below you is pushing
on your brake lines. Your canopy could stall if you apply as little as
half brakes. If someone docks and wraps the corner of a formation it can
cause part of the formation to funnel. It can also funnel at breakoff
because the trim of the formation changes and the wing people aren't
paying attention.
Another problem is people not looking where they are going.
You should always look before you turn and not just watch the formation.
Many people have gotten wrapped by not looking where they are going on
opening. If you are staring at your toggles right after opening, you may
have an unpleasant encounter with someone else doing the same thing.
Avoid tunnel vision.

AVOIDING PROBLEMS

What can we do to prevent or minimize wraps and entanglements?
The foremost preventative measure is a thorough dirtdive. That is
the time to share techniques that work for the type of formations and
transitions that are pianned. CRW is very three dimensional and therefore
complex. Participants can easily miscalculate an approach if they are
trying something new. Don't just dirt dive the formations, share any
information that you know.
If someone is docking badly you can spread out your arms and prevent
the parachute from wrapping you. Even if it does wrap, you can extract
yourself more easily because you won't be cocooned so tightly. Nylon will
stick to itself like a Chinese finger trap when it is wound tightly
around you. But if you can give it some slack it will come loose. You
can grab the area of nylon With the most tension on it then lift it by as
little as an inch. As you let it down, it will then loosen and start sliding
down your body.
If you are in a formation and someone beiow you gets wrapped,
it would be good to hold on to him until he can sort things out. This will
give the jumper more time, and less worry, by keeping his parachute on heading.
If someone is entangled in your lines you can apply light front
riser pressure. This keeps tension in your nose and tends to keep your
parachute from spinning. The jumper may then be able to slide up your
lines which will allow his parachute to stay inflated. This front risering
must be done immediately, because once the two parachutes become entangled
one or both of you will have to cut away.
If an end cell wraps around your foot it can be difficult to release.
You can't lift the jumper's weight up with one leg and it can also injure you.
As the canopy comes around your foot, stick the other foot in there also.
This will enabie you to lift the lower jumper up and get your hands on the
canopy. It should also help prevent injury.
If just one foot is wrapped, grab your risers and turn yourself away
from the other canopy -- you'll be facing backwards under your canopy.
Now you will have a 180 degree wrap around your ankle instead of a 360
degree wrap. This should make it a lot easier to shake off the canopy.
If the canopy is collapsing and reinflating, don't fight it. Have the
bottom person cut away. The snatching action can really damage your ankles.
The bottom line in preventing or easing wraps and entanglements is
to wear proper equipment. All participants should wear shoes, socks and
long pants Or a jumpsuit. Wrist mounted altimeters am not recommended and
your RSL should be disconnected. Automatic openers are fine. If I am that
low, going that fast, I want my reserve out.
You need a CRW parachute to do safe and sane CRW. Opening at
2000 feet under your little Micro-lined skyrocket is not the time to
learn CRW.
Most importanty, learn from an expert not another novice jumper.
And always respect the safety margin of altitude.

Quote

Never done CReW. But I'm just curious: How easy or difficult is it to clear a wrap? It is my understanding that several individuals died last year from a wrap. Is it not a huge deal, where you can just push your way out of the mess and execute emergency procedures? Do you think it is the most dangerous aspect of CRW (more dangerous than say, the risk of a collision in freefall?)? Have you been in a wrap that had you thinking you were in serious trouble? Other comments and related topics will be appreciated.

[faulknerwn 36]

Quote

Never done CReW. But I'm just curious: How easy or difficult is it to clear a wrap? It is my understanding that several individuals died last year from a wrap. Is it not a huge deal, where you can just push your way out of the mess and execute emergency procedures? Do you think it is the most dangerous aspect of CRW (more dangerous than say, the risk of a collision in freefall?)? Have you been in a wrap that had you thinking you were in serious trouble? Other comments and related topics will be appreciated.

How difficult? Depends on the wrap. If I remember the incident you're thinking of - the 2 guys who got into a wrap weren't planning to do CRW, just open fly and fly near each other. They collided and it is thought they were knocked out by the impact.

[faulknerwn 36]

Quote

1) Curl up in a ball, hoping you'r smaller surface area will go completely through lines (resulting in an entanglement which you both have to cut away from).

2) Spread your arms and legs WIDE (my choice, unless it a body coming at me). Then you stop the canopy/lines from engulfing you and must throw it clear.

Course I can spread my arms wide and I'd still sail right through your lines (have done it before on big canopies.) I'll spread my lines if its a CRW canopy that I know has dacron lines. If its a micro-lined canopy I'm getting as tiny as can be.