ICON Skyhook

[bjbkkb 1]

In my journey to get my Senior rigging certification I finally got a chance to see a Skyhook. Quick question, what purpose does the 4 lbs red rigging thread serve on the skyhook? Thanks

My goal is that when all is said done I will have a big pile of well used gear and a collection of great stories.

[KRBKV 0]

SkyHook RSL

[gowlerk 1,903]

bjbkkb

In my journey to get my Senior rigging certification I finally got a chance to see a Skyhook. Quick question, what purpose does the 4 lbs red rigging thread serve on the skyhook? Thanks

The single turn of seal thread is meant to prevent the Skyhook lanyard from releasing prematurely in a cutaway. It's just enough to prevent it from slipping off the hook when it shouldn't, but not strong enough to impede the pilot chute from lifting the freebag in a total malfunction situation.

Always remember the brave children who died defending your right to bear arms. Freedom is not free.

[bjbkkb 1]

Thanks Gowlerk, I thought that was the case but wanted to ask.

My goal is that when all is said done I will have a big pile of well used gear and a collection of great stories.

[hackish 8]

Small correction to your thinking. You have 2 pieces of seal thread taking the load so the disconnect force is about 8 pounds.

-Michael

[pchapman 261]

Although to be picky -- like you :-) -- it will depend on the angle of the pull on the thread. If the looseness in the thread combined with the width of the lanyard means the thread is pulling back 180 deg opposite to the lanyard, then 8 lbs works. But if the thread is more taut, with the force diagram more of a "Y", then the end loads on the thread have to rise faster to oppose the pull, and the thread will break at less than 2 times its actual strength.

With various real life variables and geometry, who knows what the actual force will be. Haven't tried measuring it. Still just a small number of pounds.

[JerryBaumchen 1,046]

Hi Peter,

Quote

Although to be picky . . .

Also, the 8 lbs is a minimum rated strength. The actual breaking strength will almost always be more; and vary.

Jerry Baumchen

[StKilda 0]

bjbkkb

The single turn of seal thread is meant to prevent the Skyhook lanyard from releasing prematurely in a cutaway. It's just enough to prevent it from slipping off the hook when it shouldn't, but not strong enough to impede the pilot chute from lifting the freebag in a total malfunction situation.

I thought there was also a small risk that the lanyard can slip off once the skyhook flap was closed, particularly if things move about in the final flap closing sequence or perhaps after as the rig flexes in use? A correctly fitted thread will prevent this - although if it did come off - you'd be left with a "normal" RSL.