Sigma Tandem question

[tetra316 0]

So based on the sigma's design you cannot deploy the main without first deploying the drogue due to the 'safety pin'. Makes emergency procedures simpler and uniform. However, can you deploy the drogue and have the main bag come out without releasing the drogue? I'm thinking not due to the safety pin, the bag could not come out without releasing the pin therefore releasing the drogue right? That was the whole point of the safety pin and new design correct? Just want to be sure I completely understand this.

I was thinking about it from the question of what are the differences in emergency procedures from the Vector 2 to the Vector 3. Differences being no out of sequence deployments to react to.....?

[Para5-0 0]

I hope this helps, when you deploy the drogue the safety pin is automatically released for drogue fall. Allowing you to be able to pull your closing pin. If you do not throw the drogue the safety pin stays in and you can not pull your main closing pin.
If the closing loop should break or the closing pin gets knocked out after drogue inflation you will have a normal deployment.
Am I answering this correctly for you? or go to the UPT web site and take a gander at the sigma manual.

[matthewcline 0]

As Bill designed it, the container can not open till the Drogue "is set". This design does do away with the open container and drogue still in tow scenario.
It also keeps one set of EP's and or bail out proccedures for A/C emergancies as well, which hope fully reduces potentially fatal confusion.

Matt

An Instructors first concern is student safety.
So, start being safe, first!!!

[tetra316 0]

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inflation you will have a normal deployment.
Am I answering this correctly for you? or go to the UPT web site and take a gander at the sigma manual.

That's what got me to asking these questions. Manuals can be a bit convoluted. So my understanding is there is no way to have a horseshoe mal on the sigma then? And the differences in emergency procedures between the 2 & 3 is there are no out of sequence handle pulls on the 3?

[DougH 270]

How could you eliminate all chances of a horseshoe malfunction?

I pack sigmas here and there so I have taken the time to read the manual thoroughly.

You can still get one if the closing loop breaks or if the pin becomes dislodged (or is incorrectly packed and missed during the gear check) and the drogue release is pulled before the drouge is out.

"The restraining order says you're only allowed to touch me in freefall"
=P

[tetra316 0]

Ok, that makes sense but two different things would have to happen then. Main closing loop breaking and you having released the drogue before deploying it. Highly unlikely but not impossible then.

[DougH 270]

No they wouldn't have to both happen, unless my understanding of the system is wrong?

If the close loop breaks then there is nothing keeping the main container closed so that could result in an out of sequence deployment. It doesn't matter if the release was pulled in this case.

If the pin is not seated properly the drouge release can be pulled before drougue throw. This would release the closing loop, opening the main container, and once again might lead to an out of sequence deployment.

"The restraining order says you're only allowed to touch me in freefall"
=P

[tetra316 0]

What about the 'safety pin' on the drogue? From reading the manual I understood there is a main closing pin and a safety pin. So wouldn't BOTH pins have to be pulled in order for the container to open? Hence the no drogue, no main emphasis and the manual touting that the Sigma virtually eliminates out of sequence deployments?

[matthewcline 0]

IF the closing loop breaks then yes it could happen.

IF the drogues safety pin is not seated properly then yes it could happen.

If the TI doesn't do a gear check it can happen.

If maintenance is being done and the basic safety checks are being done it is reduced to a fraction of what has happened in the past.

SIGMA's hands down are the top system out there, maybe there are lighter, easier to pack, etc, but none designed safer.

Matt

An Instructors first concern is student safety.
So, start being safe, first!!!

[tetra316 0]

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IF the closing loop breaks then yes it could happen.

IF the drogues safety pin is not seated properly then yes it could happen.

If the TI doesn't do a gear check it can happen.

If maintenance is being done and the basic safety checks are being done it is reduced to a fraction of what has happened in the past.

SIGMA's hands down are the top system out there, maybe there are lighter, easier to pack, etc, but none designed safer.

Matt

Ok now I'm getting confused. Not that I wasn't already though

You said earlier "This design does do away with the open container and drogue still in tow scenario. "
I read that as eliminating the horseshoe mal. But you can still get one but more than one thing needs to happen. ie. if just the main closing pin breaks it will not give a mal unless something else also contributes. If this is not true than how can RW claim to eliminate out of sequence deployements any better than any other manufacturer.

[bclark 0]

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However, can you deploy the drogue and have the main bag come out without releasing the drogue? I'm thinking not due to the safety pin, the bag could not come out without releasing the pin therefore releasing the drogue right?

No, once the drogue is deployed the bag cannot come out without releasing the drogue.

Yes, the container can come open before the safety pin is extracted IF the main closing loop breaks. The safety pin does not hold the container closed.

It keeps you from activating a drogue release before the drogue is set. Deploying the drogue extracts the safety pin and "arms" the drogue releases.

The only two ways I can think of to have an out of sequence on a Sigma:

1: Drogue is still in the pouch. Main closing loop breaks. The container is now "unclosed" whether the safety pin is in place or not.

2: You don't check your gear and the packer does not seat the safety pin. You snag or pull a ripcord before the drogue is out.

[pilotdave 0]

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You said earlier "This design does do away with the open container and drogue still in tow scenario. "
I read that as eliminating the horseshoe mal.

If the drogue is in tow, it is not in the pouch so you don't have a horseshoe. If the closing loop breaks at that point, the main will deploy. You will not end up with a drogue in tow with an open main container, which is something that can happen on other tandem systems.

Dave

[voyagers47 0]

The design of the system greatly reduces the possibility of some scenarios but nothing is 100%. But on your original thought, the emergency procedures are the same as on the vector 2.

[tetra316 0]

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You said earlier "This design does do away with the open container and drogue still in tow scenario. "
I read that as eliminating the horseshoe mal.

If the drogue is in tow, it is not in the pouch so you don't have a horseshoe. If the closing loop breaks at that point, the main will deploy. You will not end up with a drogue in tow with an open main container, which is something that can happen on other tandem systems.

Dave

Thanks I think that was what I was getting at. If you could have the main bag out and still have the drogue attached via the safety pin, ie. deployed but not released.

[DougH 270]

Take a good look at the system, watch it being packed.

The closing loop is keeping the main container closed AND it is keeping the drogue anchored at the chimney.

If the main container opens the chimney is also released as well.

The saftey pin doesn't anchor anything... it only keeps the main pin from being pulled by either drogue release when it is properly seated through the eyelet of the main pin and its respective grommet on the container.

http://www.unitedparachutetechnologies.com/PDF/Support/Manual/SIGMA-MANUAL.zip

"The restraining order says you're only allowed to touch me in freefall"
=P

[billbooth 10]

The Sigma Tandem System has been out there for a long time, (probably millions of jumps by now) and I don't remember a single out-of-sequence deployment that has been reported to me. Nothing is perfect, but so far so good. On old school tandem systems, with 3-ring drogue release systems (mine included), out-of-sequence deployments were more or less a common occurrence.