34
$\begingroup$

My 8 year old recently got a guided tour of the parachute-packing station at the local sport airport. Afterwards she asked me what happens if the parachute is improperly packed. Since it seemed to me that each parachute is packed by one person, there is no checking of human error.

How resilient are modern sport parachutes to packing errors? I would include in that any improper packing method or the packer overlooking some detail such as wear or tears. I'm not a parachutist so I don't know the intricacies to ask a more nuanced question.

Proud father update: A bit belated, but she's no longer eight years old and she enjoys, in her words, floating on imagination.

$\endgroup$
  • 1
    $\begingroup$ Not an answer: Para-Cushion Owner Manual and Ripstop fabrics. $\endgroup$ – mins Mar 15 '15 at 13:01
41
$\begingroup$

Qualification: I am a master parachute rigger, taught the sport for 10 years and have packed a couple of thousand emergency parachutes.

I can put an apartment-size piece of nylon into a purse in under 5 minutes, and guarantee that it will open. How nicely it opens is a different question. It usually takes about 45 minutes to service an emergency parachute - 20 minutes to inspect it, 10 to fold it up nicely, another 10 to stuff it into the pack, then the paperwork. Double that time if it's a large 2-passenger parachute.

The "fold it up nicely" part is to make it go into the pack without any unsightly bulges, and the emergency packs are never a nice open bag like the main - the canopy has to be shaped around the closing apparatus and the spring-loaded extraction chute has to fit in the middle. Very little of this process has anything to do with ensuring it opens when needed.

A packer would have to be spectacularly incompetent to fold a canopy in a way that would cause it to malfunction. If you feel the fabric used to make main parachutes you will find that it is extremely slippery - good luck keeping that stuff in the proper place when it goes into the bag, but you don't need to. These things sort themselves out quite nicely most of the time.

There are two important tools used in packing emergency packs - one is appropriately called the Death Strap. It is wrapped around the middle of the canopy as you are folding it into the bag, and if you forget to remove it the canopy will not open. The other is a locking pin used to close each part of the pack in stages. Your mistake will probably make the front page of the local newspaper and involve a lot of time with your lawyer, so packers typically only own one of each and all tools are counted after each job.

Going back to the incompetent packer for a moment - the main parachute is usually packed by the owner, and very occasionally you need to open and re-close the pack. If you are lazy or rushed it is very easy to close the main pack in a way that prevents it from opening. Owners (almost) never open their emergency packs, and riggers follow a standard process to prevent these errors from happening.

$\endgroup$
  • 2
    $\begingroup$ @dotancohen If you mean mechanical damage, if your little finger doesn't go through it, it usually doesn't get fixed. Canopies can work just fine with holes your child could fit through (but we do fix them). If you mean packing errors, it really depends on exactly what happened. $\endgroup$ – paul Mar 15 '15 at 13:32
  • 8
    $\begingroup$ maybe you could add something about why sometimes chutes don't open. $\endgroup$ – rbp Mar 15 '15 at 18:00
  • 4
    $\begingroup$ @rbp User error is pretty common. Bad body position upon deployment can cause it to wrap itself up, or delay opening long enough that you run out of altitude. $\endgroup$ – paul Mar 15 '15 at 23:52
  • 1
    $\begingroup$ @rbp Those ones lack the guarantee Paul provides. :) $\endgroup$ – Farhan Mar 16 '15 at 13:15
  • 2
    $\begingroup$ Paul, I'd like to take the time to say an extra thanks. I don't know how much your answer inspired her, but she's been bugging me to take her skydiving since, and we just did so for her tenth birthday. Video link in OP. Thank you! $\endgroup$ – dotancohen Jan 19 '17 at 8:19
4
$\begingroup$

Pauls answer is good but I think there is a few parst missing.

What could you do to make a parachute not open?
A lot.
But most of the things are easily catched.

You could flip the parachute through it's lines.
That usually happens when you have landed and pick up the parachute, you put your hand at the wrong place and manage to make a wrap of some kind.
It happens easily in rushed moments or windy conditions.
How do you notice the problem?
As you pack the parachute the lines should go straight from the "backpack" (rig) and the fabric, if it intersects somewhere you got a problem.

A line could wrap around the fabric.
This is hard to do while packing and not noticing.

You could create a bag lock.
All the fabric is packed in to a nylon bag closed with rubberbands (or magnets on newer models).
For the sake of simplicity, if a line intesects another line inside the rubberbands then it could lock.
Again it's hard to not notice. But it does happen.

You could create a pack lock.
That is when you wrap the bridle the wrong way behind the closing flaps.
The result is that it can't open however much you pull (unless you pull to destruction).

All these errors can happen but they are all easily spotted.
Most of the time you don't even look for the errors when you pack a parachute, you just feel that something is not right.
But new skydivers put lots of time and effort in to looking for errors, and have checkpoints where they call for inspection of a seasoned skydiver to have a look.

When you sum it all to one sentence:
They are not resilient, but because there are a few "rules" you pack by then you need not follow them or be very sloppy to fail.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.