Forums: Skydiving: Gear and Rigging:
Skyhook input wanted

 


celayne  (D 14528)

Dec 9, 2012, 3:12 PM
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Skyhook input wanted Can't Post

I am in the process of building a new rig and I am trying to decide whether or not to put a skyhook in it. I would like to hear your thoughts and input on skyhooks and if you have used one please tell me about it.


jtiflyer  (D 27430)

Dec 9, 2012, 3:18 PM
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2 skyhook chops on spun up velos. Never want to own another rig that does not have one again. Both were camera jumps and absolutely no problem with getting clear of the risers.

Highly Recommend one.


sundevil777  (D License)

Dec 9, 2012, 3:23 PM
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http://www.dropzone.com/...p;sb=score&mh=25


Deci  (D 1046)

Dec 9, 2012, 7:06 PM
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Here's my opinion:

http://bard.ca/should-i-get-a-skyhook/


ctrph8  (D License)

Dec 9, 2012, 10:56 PM
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Re: [celayne] Skyhook input wanted [In reply to] Can't Post

My next rig will have one. An RSL and a MARD system accomplish the same thing but do it differently. My view is that under most conditions, an RSL would work just fine. The Skyhook just accomplishes it faster. This would be no big deal at altitude but if you are super low and every last foot counts, I'd prefer a Skyhook.



In reply to:
I am in the process of building a new rig and I am trying to decide whether or not to put a skyhook in it. I would like to hear your thoughts and input on skyhooks and if you have used one please tell me about it.


nigel99  (D 1)

Dec 9, 2012, 11:41 PM
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Re: [celayne] Skyhook input wanted [In reply to] Can't Post

My opinion. Any MARD adds complexity and increases the 'interaction' between the main and reserve.

The only valid argument I see for a MARD is a cutaway resulting from a canopy collision at low altitude. If you are cutting away below 1000 foot for pretty much any other reason, I think you need to question your competence or safety as a jumper.

I tend to subscribe to the KISS principle and so any MARD is not something I'd choose at the moment. But when I order a new container, I'll re-evaluate my stance.


woppyvac  (D 33147)

Dec 10, 2012, 8:41 AM
Post #7 of 64 (4935 views)
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Re: [celayne] Skyhook input wanted [In reply to] Can't Post

The never ending discussion. :)

Personally. I ordered my rig without a RSL or Skyhook. NOT BECAUSE IM CHEAP but because 99% of the time I pull 3K or higher giving me enough time to cut away and return to an arch before deploying my reserve. I dont want to be in a spinning mal cut away, be butt backwards, and my reserve tangling around me etc. knock on wood - 0 reserve rides thus far.


danornan  (D 11308)

Dec 10, 2012, 8:53 AM
Post #8 of 64 (4920 views)
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In reply to:
The never ending discussion. :)

Personally. I ordered my rig without a RSL or Skyhook. NOT BECAUSE IM CHEAP but because 99% of the time I pull 3K or higher giving me enough time to cut away and return to an arch before deploying my reserve. I dont want to be in a spinning mal cut away, be butt backwards, and my reserve tangling around me etc. knock on wood - 0 reserve rides thus far.

Skyhook or RSL is not for that 99% of the time! It's for that 1% of the time.....


fluffyduckie  (B 33293)

Dec 10, 2012, 9:10 AM
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Re: [celayne] Skyhook input wanted [In reply to] Can't Post

You always have the option to disconnect your RSL. It will add value to the rig at resale.


JohnSherman  (D 2105)

Dec 10, 2012, 9:11 AM
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Quote:
My view is that under most conditions, an RSL would work just fine. The Skyhook just accomplishes it faster.

Not necessarily, See: https://www.youtube.com/watch?v=ze0Rcp7E0to


erdnarob  (D 364)

Dec 11, 2012, 6:56 PM
Post #11 of 64 (4684 views)
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Re: [celayne] Skyhook input wanted [In reply to] Can't Post

I have had two total malfuctions and deployed my reserve without any problem. Since in this case my reserve pilot chute was in charge of the deployment, my skyhook released from the RLS as designed.


ctrph8  (D License)

Dec 11, 2012, 11:27 PM
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I meant that all things being equal, a skyhook accomplishes it faster. Different rigs, different jumpers and different canopies would not be a reliable way to determine what was faster. I have no idea whether or not any of those were the same or different beyond the obvious difference in rig manufacturers. In that case, the Racer was faster. If you were comparing a skyhook equipped Javelin to an RSL equipped Javelin with the same jumper and same reserve canopies, that would give some useful information.






In reply to:
Quote:
My view is that under most conditions, an RSL would work just fine. The Skyhook just accomplishes it faster.

Not necessarily, See: https://www.youtube.com/watch?v=ze0Rcp7E0to


ChrisHoward  (D 28490)

Dec 12, 2012, 5:50 AM
Post #13 of 64 (4573 views)
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In reply to:
I am in the process of building a new rig and I am trying to decide whether or not to put a skyhook in it. I would like to hear your thoughts and input on skyhooks and if you have used one please tell me about it.

They are awesome. I have at least 8 skyhook cut aways and am always impressed with the results.


ChrisHoward  (D 28490)

Dec 12, 2012, 5:56 AM
Post #14 of 64 (4566 views)
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Re: [nigel99] Skyhook input wanted [In reply to] Can't Post

[replyThe only valid argument I see for a MARD is a cutaway resulting from a canopy collision at low altitude. If you are cutting away below 1000 foot for pretty much any other reason, I think you need to question your competence or safety as a jumper.That is a very un-educated opinion right there. The benefits of a skyhook extend far beyond the circumstances you have described. Jumping with a skyhook has nothing to do with competence.


ChrisHoward  (D 28490)

Dec 12, 2012, 6:00 AM
Post #15 of 64 (4559 views)
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In reply to:
The never ending discussion. :)

Personally. I ordered my rig without a RSL or Skyhook. NOT BECAUSE IM CHEAP but because 99% of the time I pull 3K or higher giving me enough time to cut away and return to an arch before deploying my reserve. I dont want to be in a spinning mal cut away, be butt backwards, and my reserve tangling around me etc. knock on wood - 0 reserve rides thus far.
Firstly, you can still get yourself into as much trouble cutting away at 3000ft as you can from 1500ft. Secondly, my skyhook has always performed well for me and I can assure you that a Velo at 3-1 wingloading gets to spinning pretty fast.


nigel99  (D 1)

Dec 12, 2012, 2:33 PM
Post #16 of 64 (4465 views)
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In reply to:
[replyThe only valid argument I see for a MARD is a cutaway resulting from a canopy collision at low altitude. If you are cutting away below 1000 foot for pretty much any other reason, I think you need to question your competence or safety as a jumper.
That is a very un-educated opinion right there. The benefits of a skyhook extend far beyond the circumstances you have described. Jumping with a skyhook has nothing to do with competence.
Please could you explain more? I certainly didn't mean to imply that jumpers with skyhooks are in anyway incompetent, just that one of the most common reasons that I've heard for having a skyhook is that you can cutaway at 300ft. I hear that much more frequently than anything else and find it worrying, as with one exception the person couldn't explain why they would be cutting away below 1k.


Quagmirian  (A 110392)

Dec 12, 2012, 3:22 PM
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Not many people plan to cutaway below 1000 feet. The videographer in Bill Booth's Skyhook video demonstrates this. Even though he responded well to his malfunction and made the decision to cutaway pretty early on, he took a long time to go for his reserve handle.


jtiflyer  (D 27430)

Dec 12, 2012, 3:33 PM
Post #18 of 64 (4420 views)
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In reply to:
In reply to:
[replyThe only valid argument I see for a MARD is a cutaway resulting from a canopy collision at low altitude. If you are cutting away below 1000 foot for pretty much any other reason, I think you need to question your competence or safety as a jumper.
That is a very un-educated opinion right there. The benefits of a skyhook extend far beyond the circumstances you have described. Jumping with a skyhook has nothing to do with competence.

Please could you explain more? I certainly didn't mean to imply that jumpers with skyhooks are in anyway incompetent, just that one of the most common reasons that I've heard for having a skyhook is that you can cutaway at 300ft. I hear that much more frequently than anything else and find it worrying, as with one exception the person couldn't explain why they would be cutting away below 1k.
There is also the case at the Dubai cup 2011 when a Petra canopy collapsed mid turn. Pilot cut away and lived because he had a skyhook.

Canopies can also collapse in turbulence, which is more severe and dangerous closer to the ground naturally.


nigel99  (D 1)

Dec 12, 2012, 4:04 PM
Post #19 of 64 (4402 views)
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In reply to:
Not many people plan to cutaway below 1000 feet. The videographer in Bill Booth's Skyhook video demonstrates this. Even though he responded well to his malfunction and made the decision to cutaway pretty early on, he took a long time to go for his reserve handle.

You say that not many people plan to and yet in my personal experience it has been a common reason for getting a skyhook. I see far too many jumpers who have never bothered to think about what they are jumping. AADs are prime examples, and I've been in the situation of being the least experienced person on a ferry flight, but the only one who knew what to do. The most experienced person switched their aad on, flew to a new dz 1500ft higher and didn't realise there might be a problem with that approach. So you'll find I think lots, ask a bucket load of questions and then make a decision.

Clearly lots of people with thousands of jumps see significant value in a MARD, and as I would be shocked if their motive was the ability to cutaway at 300ft (the commonly touted figure). That's why I'm pretty keen to hear why they made the choice.


ChrisHoward  (D 28490)

Dec 13, 2012, 5:59 AM
Post #20 of 64 (4256 views)
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In reply to:
In reply to:
[replyThe only valid argument I see for a MARD is a cutaway resulting from a canopy collision at low altitude. If you are cutting away below 1000 foot for pretty much any other reason, I think you need to question your competence or safety as a jumper.
That is a very un-educated opinion right there. The benefits of a skyhook extend far beyond the circumstances you have described. Jumping with a skyhook has nothing to do with competence.

Please could you explain more? I certainly didn't mean to imply that jumpers with skyhooks are in anyway incompetent, just that one of the most common reasons that I've heard for having a skyhook is that you can cutaway at 300ft. I hear that much more frequently than anything else and find it worrying, as with one exception the person couldn't explain why they would be cutting away below 1k.So lets agree that if somebody touts a 300ft cut away as the only reason for having a skyhook then they are obviously a moron. I too would be worried about people who express that as the only benefit.
I personally feel that the biggest benefit of the skyhook is the greatly reduced chance of incidents between cut away and reserve deployment. Everyone knows that you need to get stable again for a clean reserve deployment after cutting away. The skyhook will have a reserve over your head before you ever have a chance of getting unstable therefore eliminating the chance of a myriad of problematic scenarios.
I have also had my fair share of non-skyhook cutaways so I have no problem dealing with that too. But it is a much more drawn out process where you need to be on your A game. Can every one perform their best immediately after a cut away? I doubt it. Hell I have at least 14 cut aways and my heart still gets to pumping every time.
The skyhook simplifies cut aways and has multiple safety benefits over a free fall cut away. Why wouldn't you want to utilize that added security?
P.S. This obviously doesn't account for canopy wraps.


JohnSherman  (D 2105)

Dec 13, 2012, 9:32 AM
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Quote:
Not necessarily, See: https://www.youtube.com/watch?v=ze0Rcp7E0to
I have been nit picked on this as to which one is quicker. They are close, no question The Racer without a Skyhook and a Vector with one. You judge the risk and cost value.

Now lets look at the big canopies with the more demanding deployments, like tandem.
Try as I may I haven't seen a good tandem video with a Skyhook to compare with this actual field video. See: https://www.youtube.com/watch?v=FtNKXDW0Ixo

The tandem deploys the reserve in 4 seconds after a cutaway from a 500 sq. Ft. canopy with a broken line. Very low deployment speed. You can hear the pair talking.

Show me a Tandem Skyhook video which is as fast.


airtwardo  (D License)

Dec 13, 2012, 10:05 AM
Post #22 of 64 (4181 views)
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Re: [JohnSherman] Skyhook input wanted [In reply to] Can't Post

 

Show me a Tandem Skyhook video which is as fast.



https://www.youtube.com/watch?v=srZqgJ8G85U


This one is pretty quick ya gotta admit.

Personally, I don't see the downside of the extra complexity as being worth it to 'me'...but in the right circumstances it does seem to do it's job.
Attachments: skyhook tandem.JPG (72.7 KB)


JohnSherman  (D 2105)

Dec 13, 2012, 12:10 PM
Post #23 of 64 (4143 views)
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Quote:
https://www.youtube.com/watch?v=srZqgJ8G85U


This one is pretty quick ya gotta admit.

Yeah, but not even close to “as quick”. The Racer Tandem does it in 4 seconds, the one on the video above takes almost 6 seconds. Hard to tell exactly when the canopy is landable. Win to the Racer by a bunch. Racer Tandem deployment: https://www.youtube.com/...&feature=mh_lolz

This certainly substantiates my assertion the Skyhook is not necessarily faster. In some cases (Tandem) it is still slower than the Racer.
Get out you stop watches folks or one of you video types could match them side by side.


airtwardo  (D License)

Dec 13, 2012, 1:04 PM
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In reply to:
Quote:
https://www.youtube.com/watch?v=srZqgJ8G85U


This one is pretty quick ya gotta admit.

Yeah, but not even close to “as quick”. The Racer Tandem does it in 4 seconds, the one on the video above takes almost 6 seconds. Hard to tell exactly when the canopy is landable. Win to the Racer by a bunch. Racer Tandem deployment: https://www.youtube.com/...&feature=mh_lolz

This certainly substantiates my assertion the Skyhook is not necessarily faster. In some cases (Tandem) it is still slower than the Racer.
Get out you stop watches folks or one of you video types could match them side by side.


Obviously a lot of variables like canopy type & rigger influence can make a difference, but unless the clocks on the videos are way off...


(This post was edited by airtwardo on Dec 13, 2012, 1:07 PM)
Attachments: Cutaway~47sec.JPG (98.7 KB)
  Chop plus 10 sec..JPG (77.2 KB)
  Skyhook chop.JPG (75.5 KB)
  Skyhook chop pluse 7 seconds.JPG (79.8 KB)


ctrph8  (D License)

Dec 13, 2012, 8:38 PM
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Re: [jtiflyer] Skyhook input wanted [In reply to] Can't Post

 
I was looking for the video of that for my first post. Could you find a link? That was what opened my eyes about the Skyhook.





In reply to:
There is also the case at the Dubai cup 2011 when a Petra canopy collapsed mid turn. Pilot cut away and lived because he had a skyhook.

/reply]


craigbey  (C 31991)

Dec 14, 2012, 4:02 AM
Post #26 of 64 (1898 views)
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JPX chop...
http://www.youtube.com/watch?v=xeO4uY8uruQ


JohnSherman  (D 2105)

Dec 14, 2012, 1:36 PM
Post #27 of 64 (1825 views)
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Quote:
Obviously a lot of variables like canopy type & rigger influence can make a difference, but unless the clocks on the videos are way off...
The clocks aren’t off, you are correct and I have learned a bunch and proven a theory.
Both cutaways were from fully deployed mains. That hurts the RSL and helps the Skyhook.
Reason: The RSL is always the same; it is consistent because it always uses the pilot chute which will always have the same drag capabilities. The Skyhook is faster when it has the very high drag of a fully inflated canopy but it will slow down depending upon the drag of the malfunctioned main. As the drag of the main (which is working as a pilot chute) decreases due to an increased severity of a malfunction on the main, the rapidity of the deployment also decreases. My previous views and timings were of higher speed mals to the extent where the malfunctioned main had no drag and the main pilot chute was doing all of the work. This can be dangerous if the main PC is collapsible and has collapsed. In a bag lock the collapsible PC doesn’t collapse with the bag closed. This is where Tandem gets tricky. The drogue has already collapsed upon release and is not available to assist the main if it has deficient drag. So now we are back to depending on the reserve pilot chute which if any good we wouldn’t need the Skyhook.


airtwardo  (D License)

Dec 14, 2012, 2:03 PM
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In reply to:
Quote:
Obviously a lot of variables like canopy type & rigger influence can make a difference, but unless the clocks on the videos are way off...
The clocks aren’t off, you are correct and I have learned a bunch and proven a theory.
Both cutaways were from fully deployed mains. That hurts the RSL and helps the Skyhook.
Reason: The RSL is always the same; it is consistent because it always uses the pilot chute which will always have the same drag capabilities. The Skyhook is faster when it has the very high drag of a fully inflated canopy but it will slow down depending upon the drag of the malfunctioned main. As the drag of the main (which is working as a pilot chute) decreases due to an increased severity of a malfunction on the main, the rapidity of the deployment also decreases. My previous views and timings were of higher speed mals to the extent where the malfunctioned main had no drag and the main pilot chute was doing all of the work. This can be dangerous if the main PC is collapsible and has collapsed. In a bag lock the collapsible PC doesn’t collapse with the bag closed. This is where Tandem gets tricky. The drogue has already collapsed upon release and is not available to assist the main if it has deficient drag. So now we are back to depending on the reserve pilot chute which if any good we wouldn’t need the Skyhook.


http://www.youtube.com/watch?v=bmmxBP2zp9o


Almost looks like the reserve pilot chute beats the skyhook as you suggested.


(This post was edited by airtwardo on Dec 14, 2012, 2:09 PM)
Attachments: Baglock chop skyhook.JPG (86.0 KB)
  plus 2 sec.JPG (95.4 KB)


JohnSherman  (D 2105)

Dec 14, 2012, 3:21 PM
Post #29 of 64 (1780 views)
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Re: [airtwardo] Skyhook input wanted [In reply to] Can't Post

Quote:
Almost looks like the reserve pilot chute beats the skyhook as you suggested.

It does.
I downloaded the video and brought it into my Video Editor which has been down for over a week. Your first capture “Bag lock chop” is a long time after Riser Release. The risers are halfway up the fully extended reserve bridle. On my time line it occurs at 1:01.05
I used a different time line but they are all relative. I get:
Chop @ 1:00.10
Your Bag Lock Chop picture @1:01.5
Reserve bag out of container@ 1:01.09
Reserve landable/slider down @ 1:08.08

Remember that 13 foot bridle with a PC on one end and a bag on the other is about 16 feet or the distance of separation in the first second. That is commensurate with my observation.
From Chop to Landable I get 7 seconds and 23 frames @ 25 FPS that’s 7.92 seconds.
I don’t believe you can give the Skyhook much credit for this one.


Incidentally; This is a great video to show how a tandem pair go onto their back when a bag lock occurs. Vasilli was correct.


theonlyski  (D License)

Dec 14, 2012, 3:45 PM
Post #30 of 64 (1772 views)
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In reply to:
From Chop to Landable I get 7 seconds and 23 frames @ 25 FPS that’s 7.92 seconds.

Judging from those time stamps and the duration from chop to the canopy open and landable... I think you were only looking at the slow-motion portion, not the full speed one immediately afterwords.


airtwardo  (D License)

Dec 14, 2012, 5:41 PM
Post #31 of 64 (1745 views)
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In reply to:
Quote:
Almost looks like the reserve pilot chute beats the skyhook as you suggested.

It does.
I downloaded the video and brought it into my Video Editor which has been down for over a week. Your first capture “Bag lock chop” is a long time after Riser Release. The risers are halfway up the fully extended reserve bridle. On my time line it occurs at 1:01.05
I used a different time line but they are all relative. I get:
Chop @ 1:00.10
Your Bag Lock Chop picture @1:01.5
Reserve bag out of container@ 1:01.09
Reserve landable/slider down @ 1:08.08

Remember that 13 foot bridle with a PC on one end and a bag on the other is about 16 feet or the distance of separation in the first second. That is commensurate with my observation.
From Chop to Landable I get 7 seconds and 23 frames @ 25 FPS that’s 7.92 seconds.
I don’t believe you can give the Skyhook much credit for this one.


Incidentally; This is a great video to show how a tandem pair go onto their back when a bag lock occurs. Vasilli was correct.

Yeah I'm just using movie player on an old Dell, I know there were frames I couldn't 'stop' the player on...best I could do.

I could kinda tell the PC beat the SH but with this computer I couldn't be sure.

Thanks for the clarification.


blueblur  (A 64923)

Dec 15, 2012, 2:05 PM
Post #32 of 64 (1664 views)
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In reply to:
Quote:
Obviously a lot of variables like canopy type & rigger influence can make a difference, but unless the clocks on the videos are way off...
The clocks aren’t off, you are correct and I have learned a bunch and proven a theory.
Both cutaways were from fully deployed mains. That hurts the RSL and helps the Skyhook.
Reason: The RSL is always the same; it is consistent because it always uses the pilot chute which will always have the same drag capabilities. The Skyhook is faster when it has the very high drag of a fully inflated canopy but it will slow down depending upon the drag of the malfunctioned main. As the drag of the main (which is working as a pilot chute) decreases due to an increased severity of a malfunction on the main, the rapidity of the deployment also decreases. My previous views and timings were of higher speed mals to the extent where the malfunctioned main had no drag and the main pilot chute was doing all of the work. This can be dangerous if the main PC is collapsible and has collapsed. In a bag lock the collapsible PC doesn’t collapse with the bag closed. This is where Tandem gets tricky. The drogue has already collapsed upon release and is not available to assist the main if it has deficient drag. So now we are back to depending on the reserve pilot chute which if any good we wouldn’t need the Skyhook.

In general, wouldn't a malfunctioning main generate more than the 18lbs of drag on a RPC? Even in a baglock or streamer situation? In a baglock, the main's PC is still functioning, correct? Therefore, a Skyhook should generally be faster than an RSL right?


ChrisHoward  (D 28490)

Dec 15, 2012, 2:45 PM
Post #33 of 64 (1650 views)
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In reply to:
In general, wouldn't a malfunctioning main generate more than the 18lbs of drag on a RPC? Even in a baglock or streamer situation? In a baglock, the main's PC is still functioning, correct? Therefore, a Skyhook should generally be faster than an RSL right?

I would say yes the skyhook would be faster in almost all situations. Bag locks are an exception though as they could go either way. The beauty of the skyhook is that if the PC ends up being faster the skyhook is designed to seperate from the main and allow for a standard deployment.


Deyan  (D 322)

Dec 15, 2012, 2:53 PM
Post #34 of 64 (1649 views)
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In reply to:
In general, wouldn't a malfunctioning main generate more than the 18lbs of drag on a RPC? Even in a baglock or streamer situation? In a baglock, the main's PC is still functioning, correct? Therefore, a Skyhook should generally be faster than an RSL right?

Nope....

The Drogue ( PC ) on a Sigma Tandem collapses before it pulls the bag.
The Racer RPC generate 190 lbs pull force at terminal.

The problem with the skyhook is that the system is complicates and yet unreliable. Sometimes it does its job, sometimes it doesn't. And that has nothing to do with the drag of the main. Spinning main will produce a lot more drag than any RPC and yet, skyhooks disconnects.

Check this video out:

http://www.youtube.com/watch?v=bzKd8e47icY

A streamer will produce enough force to stand the tandem pair up, but apparently less than the mesh less Vector 2 RPC.
I can't believe that...


Premier skydiverek  (C 41769)

Dec 15, 2012, 3:06 PM
Post #35 of 64 (1645 views)
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In reply to:
In reply to:
In general, wouldn't a malfunctioning main generate more than the 18lbs of drag on a RPC? Even in a baglock or streamer situation? In a baglock, the main's PC is still functioning, correct? Therefore, a Skyhook should generally be faster than an RSL right?

I would say yes the skyhook would be faster in almost all situations. Bag locks are an exception though as they could go either way. The beauty of the skyhook is that if the PC ends up being faster the skyhook is designed to seperate from the main and allow for a standard deployment.

Yes, check the segment starting at 8:08:

http://www.youtube.com/watch?v=z-WBBLAgE_s

 


JohnSherman  (D 2105)

Dec 15, 2012, 6:46 PM
Post #36 of 64 (1602 views)
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Quote:
In general, wouldn't a malfunctioning main generate more than the 18lbs of drag on a RPC? Even in a baglock or streamer situation?

No, and the bad part is that you can't rely on it or predict it. It varies from way more drag than you need to not enough drag. You could have in situations such as twisted lines and a full canopy where you got more drag than you need, but there are videos of streamers on YouTube that, because you are vertical, you are falling faster than you would be if you were on you belly, no drag there. If your main pilot chute is collapsible, as it always is on Skyhook tandem, you will have no drag and you must go back to and rely on the reserve pilot chute which has only 2.3 Effective Sq. Ft.
At the point in the deployment where you are quoting 18 pounds (1 second after release from a 20FPS descending main at 2000 ft. on that model of pilot chute only) there is only 3 pound per sq. ft. resistive pressure available.
With 2.3 Effective Square feet on the Skyhook reserve pilot chute you will have only 6.9 pounds of drag not 18. That’s why some rigs have a Skyhook. It takes more than 6.9 pounds of drag to pull a tightly packed bag out of the reserve container especially if the reserve weighs more than 7 pounds.

The point is; that the Skyhook is sometimes faster and sometimes slower than a Racer with an RSL. The Racer will be predictable and consistent and the Skyhook will vary depending on the severity of the malfunction.

BTW: That 18 pound number you have latched on to is the maximinum allowable extraction force of the reserve bag on any rig. Most pilot chutes will just barely pull it and some won't at all. They are the ones who need a Skyhook.


Premier skydiverek  (C 41769)

Dec 15, 2012, 7:08 PM
Post #37 of 64 (1596 views)
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Re: [skydiverek] Skyhook input wanted [In reply to] Can't Post

Another Skyhook compilation:

http://www.youtube.com/watch?v=5PBgEfJ4PAU


JerryBaumchen  (D 1543)

Dec 15, 2012, 9:00 PM
Post #38 of 64 (1575 views)
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Re: [blueblur] Skyhook input wanted [In reply to] Can't Post

Hi blue,

Quote:
wouldn't a malfunctioning main generate more than the 18lbs of drag

Back about 1965, when the Stevens Lanyard was first put into general useage, someone found a PhD physicist who did some calculations. He used an average weight person, the length of the lanyard, etc, etc, and came up with a force at the reserve ripcord handle of something on the order of 9,000 lbs.

I doubted his numbers as the time & still doubt them. But if you take a 100 lbs and drop it 2 ft or so, you will generate a lot of force at the end of the line ( or lanyard Tongue ).

Just my rememberances,

JerryBaumchen

PS) When I was doing the testing of the RAX System I tested would it would take to just break the red riggers thread tacking and came up with an average of 25 lbs; the high being 26 lbs and the low being 24 lbs. I did a lot of drops in my garage and the tacking always broke very quickly. For those drops I used a total weight of ~30-35 lbs.


Joellercoaster  (D 105792)

Dec 16, 2012, 3:02 AM
Post #39 of 64 (1545 views)
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Re: [airtwardo] Skyhook input wanted [In reply to] Can't Post

In reply to:
Personally, I don't see the downside of the extra complexity as being worth it to 'me'...but in the right circumstances it does seem to do it's job.

This is about how I feel about it - my current rig has a Skyhook, but it's a pretty even decision either way and I wake up feeling differently about it about once a week. I am very pro-RSL, but a bit conflicted nowadays about the MARD part.

One thing that nobody here has mentioned yet though is the Collins lanyard built into the Skyhook. Extra complexity for sure, but it certainly feels like an important safety feature if you're going to have an RSL at all.

(Also, to newer jumpers who watch that Petra mal video and suddenly realise they want a Skyhook - are you jumping a tiny experimental canopy and doing massive turns into the gates? Then maybe not so useful as an example. Note this goes for me too Tongue)


(This post was edited by Joellercoaster on Dec 16, 2012, 3:04 AM)


craigbey  (C 31991)

Dec 16, 2012, 8:01 AM
Post #40 of 64 (1501 views)
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Re: [Joellercoaster] Skyhook input wanted [In reply to] Can't Post

Quote:
Also, to newer jumpers who watch that Petra mal video and suddenly realise they want a Skyhook - are you jumping a tiny experimental canopy and doing massive turns into the gates? Then maybe not so useful as an example.

Yeah, that kind of stuff can only happen to those tiny, experimental canopies under extreme circumstances. Equipment failures or malfunctions don't happen to 'normal gear'.

Wink

Why are you pro-RSL?
Why are you sometimes conflicted about MARD's?

Maybe just me, but if I felt conflicted about any part of my kit, it would stay on the ground.


erdnarob  (D 364)

Dec 16, 2012, 5:58 PM
Post #41 of 64 (1430 views)
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Re: [celayne] Skyhook input wanted [In reply to] Can't Post

One important feature of the skyhook, when having a spinning malfunction or when the jumper's body is not being vertical, both followed by a cut away, is that the reserve deployment is done with bridle, risers and jumper's body in line. That provides a better chance for an uneventful deployment since both sides of the reserve canopy will inflate at the same time.

OTOH, when a reserve is deployed by its pilot chute, this pilot chute goes up vertically whatever is the position of the jumper. If the jumper's body is sideway or not in line with risers, the lowest riser lines will make the corresponding part of the canopy inflate first creating possible inflation problems


ctrph8  (D License)

Dec 17, 2012, 9:43 AM
Post #42 of 64 (1354 views)
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Re: [skydiverek] Skyhook input wanted [In reply to] Can't Post

I watched that a few times. Those were fast!

I want one! The reality is that I'll probably never "need" one as opposed to an RSL... But I want one. I also hope to never find out exactly where the line is.

Also, I've looked for other skyhook videos. The owner of that one should change the title or add key words so that it comes up under a search for "Skyhook".



In reply to:
Another Skyhook compilation:

http://www.youtube.com/watch?v=5PBgEfJ4PAU


sundevil777  (D License)

Dec 17, 2012, 11:34 AM
Post #43 of 64 (1325 views)
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Re: [ctrph8] Skyhook input wanted [In reply to] Can't Post

It is easy to think that a MARD has no disadvantages, or only minimal problems that could happen in only rare circumstances. Before people conclude this, consider that a guy intimately involved with the concept thinks that it shold only be applied when you might need to cutaway at a few hundred feet. Here is his contribution to the topic:

http://www.dropzone.com/...post=4299972#4299972


(This post was edited by sundevil777 on Dec 17, 2012, 11:35 AM)


DocPop  (C License)

Dec 17, 2012, 11:42 AM
Post #44 of 64 (1317 views)
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Re: [erdnarob] Skyhook input wanted [In reply to] Can't Post

In reply to:
One important feature of the skyhook, when having a spinning malfunction or when the jumper's body is not being vertical, both followed by a cut away, is that the reserve deployment is done with bridle, risers and jumper's body in line. That provides a better chance for an uneventful deployment since both sides of the reserve canopy will inflate at the same time.

OTOH, when a reserve is deployed by its pilot chute, this pilot chute goes up vertically whatever is the position of the jumper. If the jumper's body is sideway or not in line with risers, the lowest riser lines will make the corresponding part of the canopy inflate first creating possible inflation problems

Why would the reserve pilot chute pull in a different direction a cutaway main canopy?

The strength of the spring is not going to extract the bag (as we know from ground cutaways) and the relative wind would affect both the PC and the cutaway main in the same direction.


Joellercoaster  (D 105792)

Dec 17, 2012, 12:13 PM
Post #45 of 64 (1298 views)
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Re: [craigbey] Skyhook input wanted [In reply to] Can't Post

In reply to:
Why are you pro-RSL?
Why are you sometimes conflicted about MARD's?

Maybe just me, but if I felt conflicted about any part of my kit, it would stay on the ground.

That's actually a fair question (especially the last implied one).

So... I'm pro-RSL because I think the getting a reserve pilot chute out as soon as the main is cut away is more useful than being able to time your reserve deployment after cutaway, for most of us. CRW (voluntary or otherwise) aside, it just doesn't seem helpful. Whereas trying and failing for stability, losing alti awareness, dislodging or being unable to grasp the reserve handle, are all things that have happened to otherwise pretty together people.

If you have a big snaggy camera mount, I can see the point. If you have a canopy where malfunctions are going to be radical, then that's just not something I know that much about. But for most of us, the balance of probability seems to side with it being a good idea.

Conflict about MARDs is just to do with benefit. They cost a bunch of money, they give riggers and container manufacturers more opportunity to make mistakes, they force design changes in rigs to accommodate them, and they make people feel safer than maybe they are.

In return, they get a reserve out slightly quicker, maybe in a better orientation... sometimes.

On balance I think my Skyhook makes me safer, probably. Now that I've shelled out for it. But I'm just less convinced it was a no-brainer than I am about the plain ol' RSL on my previous rig.


(This post was edited by Joellercoaster on Dec 17, 2012, 12:13 PM)


ChrisHoward  (D 28490)

Dec 20, 2012, 5:40 AM
Post #46 of 64 (1179 views)
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Re: [DocPop] Skyhook input wanted [In reply to] Can't Post

In reply to:
Why would the reserve pilot chute pull in a different direction a cutaway main canopy?

The higher extraction force of a MARD limits the potential for the jumper to rotate off axis after a cut away. A standard RSL takes longer to function and therefore allows more time for the jumper to possibly tumble after cutaway.


ChrisHoward  (D 28490)

Dec 20, 2012, 5:58 AM
Post #47 of 64 (1171 views)
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Re: [Joellercoaster] Skyhook input wanted [In reply to] Can't Post

In reply to:
Conflict about MARDs is just to do with benefit. They cost a bunch of money,
Not that much money, especially not if you price it out over the lifetime of the rig. $250 over 1000 jumps is 25c a jump and we know that harnesses can last 10 times that long.
In reply to:
they give riggers and container manufacturers more opportunity to make mistakes,
Firstly I don't see this at all. Definitely not more so than any other components on the rig. And lets face it, there are a number of RSL designs on the market that actually have caused incidents and fatalities. Unless someone corrects me on this I am not aware of any Skyhook related fatalities. So your argument for RSL over Skyhook is flawed here.

In reply to:
In return, they get a reserve out slightly quicker, maybe in a better orientation... sometimes.
I would say it gets the reserve out significantly faster and in a much better orientation and lot more than just "sometimes". I can understand the Skyhook no Skyhook debate but I cannot relate to your RSL over Skyhook debate. Especially if you begin to reference costs as a factor.


linebckr83  (D 30571)

Dec 20, 2012, 8:33 AM
Post #48 of 64 (1131 views)
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Re: [ChrisHoward] Skyhook input wanted [In reply to] Can't Post

In reply to:
Unless someone corrects me on this I am not aware of any Skyhook related fatalities. So your argument for RSL over Skyhook is flawed here.

There was the NC tandem double fatality a few years ago. A Cypres fire during the main canopy snivel that caused the reserve bag to fall out and backload the red skyhook lanyard. A cutaway soon followed and the reserve never came out of the bag. In response UPT modified the packing process to include the staging loop to prevent this seemingly rare type of accident. That's the only one I can think of.


(This post was edited by linebckr83 on Dec 20, 2012, 8:42 AM)


ChrisHoward  (D 28490)

Dec 20, 2012, 9:01 AM
Post #49 of 64 (1118 views)
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Re: [linebckr83] Skyhook input wanted [In reply to] Can't Post

In reply to:
In reply to:
Unless someone corrects me on this I am not aware of any Skyhook related fatalities. So your argument for RSL over Skyhook is flawed here.

There was the NC tandem double fatality a few years ago. A Cypres fire during the main canopy snivel that caused the reserve bag to fall out and backload the red skyhook lanyard. A cutaway soon followed and the reserve never came out of the bag. In response UPT modified the packing process to include the staging loop to prevent this seemingly rare type of accident. That's the only one I can think of.

As far as I understand it the theory of the skyhook backloading was entirely speculation.


(This post was edited by ChrisHoward on Dec 20, 2012, 9:10 AM)


ChrisHoward  (D 28490)

Dec 20, 2012, 9:18 AM
Post #50 of 64 (1105 views)
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Re: [linebckr83] Skyhook input wanted [In reply to] Can't Post

In reply to:
In response UPT modified the packing process to include the staging loop to prevent this seemingly rare type of accident.

Yes UPT did add the staging loop to ensure that the free bag would stay in the container in the event of a low pull/snivelling main/cypres fire/low speed scenario. This was to help prevent a two out scenario in the even that you snivel into cypres fire altitudes.
Do not interpret this as UPT adding the staging loop to prevent the freebag from backloading the skyhook to effect a cut away.


linebckr83  (D 30571)

Dec 20, 2012, 9:38 AM
Post #51 of 64 (1026 views)
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Re: [ChrisHoward] Skyhook input wanted [In reply to] Can't Post

I know why the mod was added and I didn't interpret anything. You asked for an example of a skyhook-related fatality and I listed one. I also wanted to point out how many things had to happen at once for this to happen, and how it is being prevented with the staging loop.


ChrisHoward  (D 28490)

Dec 20, 2012, 9:59 AM
Post #52 of 64 (1013 views)
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Re: [linebckr83] Skyhook input wanted [In reply to] Can't Post

In reply to:
I know why the mod was added and I didn't interpret anything. You asked for an example of a skyhook-related fatality and I listed one. I also wanted to point out how many things had to happen at once for this to happen, and how it is being prevented with the staging loop.

Then you would agree that this actually is not a skyhook related fatality? As the skyhook played no part in causing this fatality.


ufk22  (D 16168)

Dec 20, 2012, 10:32 AM
Post #53 of 64 (997 views)
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Re: [ChrisHoward] Skyhook input wanted [In reply to] Can't Post

In reply to:
In reply to:
I know why the mod was added and I didn't interpret anything. You asked for an example of a skyhook-related fatality and I listed one. I also wanted to point out how many things had to happen at once for this to happen, and how it is being prevented with the staging loop.

Then you would agree that this actually is not a skyhook related fatality? As the skyhook played no part in causing this fatality.
My understanding is this may or may not (but probably was) caused by the skyhook and its configuration at the time. The staging loop one only part of the modification, and one that was mandatory on tandems but optional on sport rigs.
The big change was a new-differnt RLS/colins ribbon assembly. On the original skyhook the RSL ribbon ran from the riser connector to the colins loop and then on to the reserve pin/skyhook. After that incident, the design was changed. There are now 2 ribbons running from the riser connector, one to the pin/skyhook and a seperate one to the colins loop. Having a reserve deploy could pull on the main riser, but would not put any pull on the colins loop.


linebckr83  (D 30571)

Dec 20, 2012, 11:29 AM
Post #54 of 64 (972 views)
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Re: [ufk22] Skyhook input wanted [In reply to] Can't Post

You are correct I forgot there was also a modification to the RSL lanyard. Either way, it was my understanding that, among many other variables, the skyhook partially contributed to the fatality which resulted in UPT making the modifications mentioned.

Chris I am a fan of the skyhook and own one myself. I'm not hinting that they are unsafe, only that it was my understanding there has been a fatality in which the skyhook was partially to blame.


ChrisHoward  (D 28490)

Dec 20, 2012, 11:40 AM
Post #55 of 64 (967 views)
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Re: [linebckr83] Skyhook input wanted [In reply to] Can't Post

In reply to:
Chris I am a fan of the skyhook and own one myself. I'm not hinting that they are unsafe, only that it was my understanding there has been a fatality in which the skyhook was partially to blame.

No offense taken at all. I still feel that the Skyhook being to blame in that particular incident was more than a little speculative. Ofcourse there is the possibilty that I don't even have a clue Smile


Deyan  (D 322)

Dec 20, 2012, 12:55 PM
Post #56 of 64 (951 views)
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Re: [ChrisHoward] Skyhook input wanted [In reply to] Can't Post

In reply to:
As far as I understand it the theory of the skyhook backloading was entirely speculation.

Sure it was. Unless you have it on video, everything is speculation. But speculation or not, the described scenario was definitely possible.

What about the student in Chicago 2 years ago. Not a fatality , but serious injury.

For its short life Skyhook has handful modifications and there are more to come.

Not to mention the disconnection rate. When the Skyhook disconnects, it works as good as the normal RSL, just 5-6 times more expensive.

Don't get me wrong. If you gonna do something stupid like cutting away below 500 ft, you'll be better with one, assuming that it will work as a MARD ,but no guarantees there. Other than that, I don't see the advantage.


linebckr83  (D 30571)

Dec 20, 2012, 1:07 PM
Post #57 of 64 (946 views)
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Re: [Deyan] Skyhook input wanted [In reply to] Can't Post

In reply to:
Not to mention the disconnection rate. When the Skyhook disconnects, it works as good as the normal RSL, just 5-6 times more expensive.

When would the skyhook disconnect and act as a normal rsl? The red safety tie thread prevents it from slipping off unless the reserve pc is activated.


Deyan  (D 322)

Dec 20, 2012, 1:49 PM
Post #58 of 64 (931 views)
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Re: [linebckr83] Skyhook input wanted [In reply to] Can't Post

In reply to:
In reply to:
Not to mention the disconnection rate. When the Skyhook disconnects, it works as good as the normal RSL, just 5-6 times more expensive.

When would the skyhook disconnect and act as a normal rsl? The red safety tie thread prevents it from slipping off unless the reserve pc is activated.

I don't know. It just does .

Here is a really nice POV video .

http://www.facebook.com/...p;type=2&theater


linebckr83  (D 30571)

Dec 20, 2012, 2:01 PM
Post #59 of 64 (925 views)
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Re: [Deyan] Skyhook input wanted [In reply to] Can't Post

Right it comes off when the reserve pc is creating more drag than the malfunctioning main. Which is a pretty rare case but apparently it happens. The vast majority of the time it only disconnects when the reserve is activated without a main canopy out.


Deyan  (D 322)

Dec 20, 2012, 2:14 PM
Post #60 of 64 (920 views)
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Re: [linebckr83] Skyhook input wanted [In reply to] Can't Post

In reply to:
Right it comes off when the reserve pc is creating more drag than the malfunctioning main. Which is a pretty rare case but apparently it happens. The vast majority of the time it only disconnects when the reserve is activated without a main canopy out.

Not so rare as you think. I can send you more videos if you wish.

I'd like to ask the people who buy the Skyhook so they can chop lower, can you be sure that the Skyhook will work as a MARD in your case?

And if somebody can explain to me , how it's possible that a 3 sq.ft reserve PC will out drag 100+ sq ft main in less than a second....

The only time when Skyhook works 100% is the UPT promo video.


Premier PhreeZone  (D License)
Moderator
Dec 20, 2012, 2:17 PM
Post #61 of 64 (918 views)
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Re: [linebckr83] Skyhook input wanted [In reply to] Can't Post

I've seen cases where the red seal loop was not super tight and the skyhook disconnected after a cutaway. The seal thread was found still in place but the skyhook had slipped off.


linebckr83  (D 30571)

Dec 21, 2012, 6:40 AM
Post #62 of 64 (869 views)
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Re: [Deyan] Skyhook input wanted [In reply to] Can't Post

Is there anybody with editing software that can analyze that video super slow? I wonder if the skyhook could pull on the bridle and activate deployment while the pc catches enough air to be trailing in the same direction but not actually overpowering the main.

I think there are far more videos of skyhooks working as a mard compared to acting like a regular rsl. Thanks for bringing up the possibility of this happening though, I wasn't aware.

My skyhook was a free option, I'm not sure if I would have paid the $250 for it (I bought a new rig from Karnage Krew before Gary went down the shitter).

Of the skyhook cutaways I've seen in person, I'm glad I have it just in case but I didn't change my hard deck any.

I think that's the thing to take away here. Sure, having a skyhook means you can generally count on quicker reserve deployments, but it shouldn't be banked on. Like any other piece of safety equipment.


Joellercoaster  (D 105792)

Dec 21, 2012, 6:46 AM
Post #63 of 64 (865 views)
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Re: [Deyan] Skyhook input wanted [In reply to] Can't Post

In reply to:
The vast majority of the time it only disconnects when the reserve is activated without a main canopy out.

Not so rare as you think. I can send you more videos if you wish.
Indeed.

I realise the plural of 'anecdote' is not 'evidence', but since everyone else here has provided little of either: my only Skyhook cutaway resulted in a disconnection and ordinary RSL deployment.

It was nothing extreme, just asymmetric twists on a semi-elliptical loaded about 1.7.

I've watched at least one other very similar chop with the same result.

Make of this what you will. I still think the Skyhook and Collins lanyard are impressive innovations, but implying that anyone who's not sure they're a good deal foolish is wrong.


DougH  (D License)

Dec 21, 2012, 1:19 PM
Post #64 of 64 (820 views)
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Re: [airtwardo] Skyhook input wanted [In reply to] Can't Post

In reply to:
Almost looks like the reserve pilot chute beats the skyhook as you suggested.

Looks like a fucking nightmare to me, and it makes me like the Strong drogue setup much better!



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