Hard cutawys

[ramon 0]

Took this off another forum.
Read learn, make your own decisions.
bloo skies
ramon
From Roger Nelson's recent update & email:
Missy called and revealed a very close call she experienced in Eloy.
Missy opened up in a severe line twist spin under her Velocity 90. She told me she immediately was thrown on her back which she knew meant the centrifugal force
would not allow her to kick out (Skydive Chicago exclusive training!). Immediately she went to cut away and couldn't. The spin intensified and with all her might she tried
and tried with both hands. Over and over with her knees curled up in her chest she tried to thrust her cut away handle but nothing worked. Soon she heard her ditter flat
line and she knew she had to do something before impact so she dumped her reserve, which then entangled around her body. She grabbed the pilot chute and free bag
and hand launched it away and it worked itself out, but with line twist. Now in a down plane well under 1,000 feet she cut away her main which released and she
frantically kicked out of her line twist. The moment she was clear she grabbed her toggles and flared for the landing. She got to a phone and told me the story. I had to sit
down even though I knew she was ok. I felt so small and powerless and all I wanted was for her to be home where I felt I could protect her. As soon as I hung up I
dropped to my knees and thanked God for her protection. Oh how I love her! Missy, you handled it and did what you had to. You were in a bad situation with no clear
recovery technique yet made split second decisions that saved your life. Be proud!
While Missy was telling me the story she kept explaining how she reverted back to her AFP training, which had been reinforced every time she went up with her AFP
students. She said she followed the "Golden Rules" and never gave up. So now that the emotions of the event have lessened, I would like to reveal why I shared this
story and what I believed happened.
Why she couldn't cut away.
Skydiving equipment manufactures independently make the different components. With the continual advancements it appears the harness and container manufactures
are still catching up with the high performance canopy manufactures. Since the risers are manufactured by the container companies, there is a gap in compatible
research for the different canopies. Nation wide information is coming in of extremely hard cut-away pulls reaching the point some have been unable to cut away like
Missy. The riser manufactures are attempting to address the problem with a hard housing sleeve that is inserted in the riser cut-away sheath. What appears to be
happening is the line twists are winding down past the lines into the risers. The twist passes the point where the cut away cables end and therefore bind up the end of
the cables, vastly increasing the cut away pull pressure. Both Kirk and I have discussed this and at this writing believe the best riser being produced is the one by
Relative Workshop. It is the most advanced design, which is typical of Bill Booth. I URGE EVERYONE JUMPING A HIGH PERFORMANCE CANOPY with a wing loading
of over 1.0 (this applies to anyone whose exit weight is more than the square footage of their main canopy) to have their risers modified with a riser cut away end cable
hard housing insert. DO IT NOW!
Please Note:
In today's environment having a toggle come free on opening is the beginning of a number of the canopy malfunctions we are seeing today. Poor Velcro, loose elastic
keepers and or riser covers have contributed to toggle being knocked off

[cobaltdan 0]

i am not against hard housings. they are a good idea,
but i do not believe they are the solution for hard cutaways w/high performance mains.
every hard cutaway situation i have looked into has had a kinked yellow cable.
the force needed to overcome the mechanical advantage of the detent mechanism formed when a yellow cable gets even the slightest kink into the gromet is huge.
we are addressing this in a different way in our up-coming rigs: the 3 ring release mechanism is fliped upside down (main ring on riser), and the yellow cable is replaced with a steel pin (system patent pending).
now there is no longer a possiblilty of either twisted risers increasing friction force on the cables because there are no cables on the risers and with the steel pin there is no possibility of a gromet kink. I felt it was the safest possible solution to redesign the entire section rather than try to implement incremental fudge fixes...
sincerely,
dan
atair

[alan 1]

Quote

The riser manufactures are attempting to address the problem with a hard housing sleeve that is inserted in the riser cut-away sheath. What appears to be happening is the line twists are winding down past the lines into the risers. The twist passes the point where the cut away cables end and therefore bind up the end of the cables, vastly increasing the cut away pull pressure. Both Kirk and I have discussed this and at this writing believe the best riser being produced is the one by Relative Workshop. It is the most advanced design,

I wonder why they feel it is superior to the one produced by Rigging Innovations?
alan

[ramon 0]

that sounds really smart.
Yellow cables are what I call "old school" sorry...piglets and double cutaway clips are really old school .
some of todays canopies are a little different from yesteryears container technology.
Although....
some are arguing, new methods of getting out of spins. My friend Derek is writing an article about aligning your links when in a hard spin to induce a flat flight with line twists. I guess that is sound (it works for him at 3.1 on a VX 60) if there is not enough friction to prevent you sliding a riser downward a little to even your links.
I have hard cutaway housings on my Vector 3 and I heard the PD swooper (serious hearsay) had his life saved on a violent velocity spinner down his risers by them ramon

[rmsmith 1]

>every hard cutaway situation i have looked into has had a
>kinked yellow cable.
>the force needed to overcome the mechanical advantage
>of the detent mechanism formed when a yellow cable gets
>even the slightest kink into the gromet is huge.
At 6'3" and 225-lbs, I opted for the standard 3-ring on my latest rig as the static moment on the smaller ring set simply produced too much tension on the locking-loop, for my comfort level.
Years ago, I cut-away a GQ Security Unit that had several broken suspension lines resulting in a fast "riser-turn" like dive. I could feel the loading on my leg-straps right away, and it was an effort to guide my hand to the cut-away pillow. However, the cut-away was "quick-n-clean", and I pulled the reserve handle after I could see the ground again following a hard arch. It all happened so fast, and I know things would have happened much faster under an elliptical canopy. There's no mistaking that high G-load feeling on your leg straps!
--
Sincerely,
Richard M. Smith
(509) 754-1126
[email protected]

[Unisyn 0]

I have been away from my desk and I have not gotten a chance to see Dropzone.com forum lately.
The problems with hard cutaways are result of a number of things. About 6 years ago we had the change the cutaway housings from fabric (soft) back to metal. Even with this change we continued to have hard cutaways. At first it was blamed on the "G" forces that develop. But later it was determined that the excess cable in the back of the risers were becoming trapped due to the friction developed in the twisting risers. (best example is a chinese hand cuffs)
The container and riser hard housing address the friction side of the hard housing but it does explain the cable damage. Cable damage can occur in two way. Extremely hard opening created high dynamic forces that actually pulls the cable into the cutaway housing end fitting or sustained load forces compressing the plastic coating.
Most manufacturer use the amp end fittings. They have a grommeted opening that is INTENDED to allow the cable to easily side by during a cutaway. Unfortunately the grommet also promotes the cable to be pull through the opening, most of the time just kinking it. That is why Mirage Systems does not use that kind of end fitting.
If you want more information about Mirage Systems cutaway systems contact them.