Horseshoe Malfunction
SkyAZ
collapsible pilot chutes for CRW last week. The opinions are my own, based
on 2,800 jumps (all types) of my own and the fact that I probably see as
many skydives as anyone in the world, on all types of gear foreign and
domestic. Bryan Burke, S&TA at Skydive Arizona.
Horseshoes
These are probably the most dangerous type of malfunction, but one of the
easiest to avoid. I agree that if you have one, step one should be release
the pilot chute and briefly attempt to clear things, depending on
altitude. But if you are out of altitude and forced to deploy into trash,
you are gambling and the odds are not heavily in your favor. Therefore, we
should all do our best to understand how these happen and prevent them,
rather than dealing with them after they occur. To the fellow surprised
that the spandex pouch didn't let go of the pilot chute: why should it?
The pull force is 90 degrees to the mouth of the pocket so it is unlikely
to ever come out. Most horseshoe mals are directly caused by poor
equipment design, use, or maintenance.
There is no excuse for bad velcro on risers or bridles. If your flap comes
open in freefall, you need to get it fixed! Tuck tabs or walrus teeth
(Javelin and Flexon) are better than velcro.
A bottom of container throw out probably has much less chance of bridle
coming out than a legstrap. This is important because the less stuff you
have coming loose, the less likely you are to have a problem. Also, the
pilot chute is better protected against an unintentional deployment. I
personally think BOC has the fewest inherent risks, except for ripcord,
which is probably safest of all deployment methods but with other
disadvantages. I won't get into the disadvantages of pull outs because
that is a separate topic.
When you put your main pin in, load it pin up (pointing towards the
reserve) rather than down so that whatever brushes your flap open will not
also push the pin out. Put the pin all the way in, not half way.
Mains too big or too small for the container are sport death. Here is one
test: with the rig on the floor, pull out your pilot chute and hold the
bridle. Lift on the bridle. If the pin comes out with very little pull
force, the loop is too loose. If the rig comes up until most of it is off
the floor, the loop is too tight. Not only can the latter situation cause
a pilot chute in tow, but the loop may break as you flex the rig while
moving about. Novices, never trust the person selling the gear to give you
an honest opinion about what mains are compatible with the container. Most
will, but your life is worth a second opinion. If there are no good
alternate opinions around because everyone works forthe DZ owner selling
you the gear, you need to get background info somewhere else. Call the
manufacturer, look up pack volumes in Para-Gear or Square One catalogs, or
even call us. We will be happy to spend 10 minutes giving you some advice
if it keeps you from coming here with death rig.
Worn loops can kill you and others and take out airplanes. You are being
criminally negligent if you do not replace your closing loop as soon as it
shows signs of wear. The standard is replace after 25% of the loop has
worn through, but err on the safe side since a loop costs about two cents
worth of material and takes about a minute to replace. This is so
important to us we give them away. Maybe ask your dz operator to do the
same. It may save his airplane some day. Since worn loops can kill you
even if they are on someone else's gear, don't jump with people who won't
maintain their equipment safely.
When routing the bridle from the pin to the pilot chute pouch, route it
under the side flap (between the side and bottom flap) rather than the
lowermost flap so that if your flap is pulled open, the bridle will not
come out with it. This only applies to flaps with tuck tabs like Vectors,
Eos', Talons, etc.
The Racer has the worst main pin protection of any rig on the market. Note
how often this design appears in photos with the flap open. (Jump Shack,
this is just an opinion but I will guess plenty of people share it)
Be very cautious about your rig in the plane and on jump run. Plan your
climb out so you don't rub against people or door jambs. Sometimes just
turning left instead of right, for example, will lessen the exposure your
pins and bridle get to things.
Don't plan dives prone to premature deployments or pulled pins. Any dive
with a high probability of funnels falls in this category. Tubes and horny
gorillas are great examples.
Now, about the collapsible pilot chute for CRW;
Bad idea. The slowest you ever go is about 2 to 4 seconds out of the door,
as you loose speed from the aircraft but haven't picked it up from
gravity. Take the bungee out or just use a regular pilot chute. On a big
seven cell, the pilot chute drag is rather insignificant. The reason CRW
canopies have retractables is to minimize the probability of entangling
with it in a wrap, not for performance. Most retractable systems require
significant work on the canopy. A very easy solution for the guy with the
PD 238 is this. Use a regular pilot chute, but shorten the bridle so it is
only about six feet long. It will hang close to the tail of the canopy,
out of the way for most casual CRW applications. As long as your container
is not too tight this shouldn't affect deployment.
Collapsible pilot chutes make a big difference on high performance
canopies because the drag is higher in proportion as the canopy gets
smaller and faster. But for a light wing loading, big canopy, they aren't
that important, are more expensive, and are another thing to go wrong. I
personally don't feel you need a collapsible unless you jump a nine cell
at a wing loading of over one to one. Another consideration is that unless
they made of zero-p fabric bungee collapsibles have a history of not being
reliable, especially if you have a short bridle as on most pull out
systems. I have towed them three times and would never buy one again,
although they are simpler than kill line collapsibles because you don't
have to worry about cocking them. However, no pilot chute - no main!
Thanks for your time.
Bryan Burke
Skydive Arizona