Tail tiedown hook

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Robodog
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Tail tiedown hook

Post by Robodog »

Club aircraft that is tied down outdoors.

I'm curious if anybody has a recommended tiedown hook that fits easily into the hole in the tail fin. We've been using a hand made two-part U-hook that has a bolt through the hole in the tail into a welded nut on the other side of the U. It works well but is a bit of a nuisance as the bolt can be dropped in the snow or grass and is not a simple mechanism.

With the length of the hole in the tail, it's difficult to conceive of a carabiner working but I'm curious if there are any elegant and simple solutions out there.
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Re: Tail tiedown hook

Post by BRS »

Tail-hook copy.jpg
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Re: Tail tiedown hook

Post by Boatguy »

I use a rock climbers sling. Loop it through and leave it. Soft, strong, quiet and can’t damage the plane.

https://www.rei.com/c/slings
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Re: Tail tiedown hook

Post by pietromarx »

I use a "soft shackle" (basically a split rope slip-knot) that has been fantastic. It also helps with winching the plane backwards into the hanger (reduces the shock transmissions).

https://www.amazon.com/gp/product/B011EO5U82/
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Re: Tail tiedown hook

Post by Boatguy »

Soft shackles work; I used them on my heavy weather staysail.

Or buy 1' of 1/4" Amsteel for $1.62; tie the knot of your choice and luggage tag it through the eye in the tail. 7,400lb breaking strength, after the knot still probably 3,500lb breaking strength.
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Re: Tail tiedown hook

Post by chili4way »

I also use a "soft shackle". Russ (@boatguy) gave me the pointer to Grog Knots (https://www.animatedknots.com/) to show how to tie one, and also to West Marine to get the Amsteel. I keep the soft shackle attached all the time, and sometimes get an advisory over the radio that "there's something hanging off your airplane's tail."

IMG_3476.jpg
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Re: Tail tiedown hook

Post by Tom-B »

I doubled a loop of 550 parachute cord that I would slip through the hole and unite the two ends of the loop within a carabiner. I would than secure the carabiner to the tie-down’s hook.

If you don’t have 550 cord laying around it’s a great thing to have as it also has many survival applications.

https://www.amazon.com/TOUGH-GRID-Grizz ... _s_sparkle

One note is that when you cut 550 cord you should singe/melt the end fibers together.
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Re: Tail tiedown hook

Post by Robodog »

Good stuff here, folks. Thanks for the pics and advice.

So, couple questions... not knowing what a soft shackle is, I did a little search and I'm wondering what the benefit is of that, as opposed to "the knot of your choice" recommended by Russ.

And, not being a rock climber I had to look up a sling too. What is that? Just a loop that has been sewn or somehow mechanically attached end-to-end?
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Re: Tail tiedown hook

Post by Boatguy »

All of these come from the same basic class of artificial fibers known as high modulus polyethylene, aka Spectra which are crazy strong and very light. I'm not a rock climber either, but yes, a sling is some spectra woven into webbing overlapped at the ends and sewn together. Strong enough to hold a climber in free fall.

Any of these will work and are more than strong enough to keep your plane's tail attached to the tie down chain (assuming they give you one). They won't stretch, they behave like metal. The choice of which solution is basically how much effort you want to put into it. I buy the slings because they're less than $10 and I was familiar with them from numerous applications on boats. They work right out of the package. Amsteel is awesome material and if you have a nearby source, for $2 and a knot, you're finished.

I could make the argument that the better choice is a class of line used for dock lines and anchor lines which are the exact opposite; very stretchy and absorb energy and shock loads rather than transmit it through to the empennage. I personally carry some of that material with carabiners and slip knots to use when there are no chains.

The parachute cord is nylon which means it will also be very stretchy and absorb shock loads. It also absorbs water, but that's not generally a problem in aviation.

IMHO, any of these is better than a metal shackle or hook hanging off your tail.
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Re: Tail tiedown hook

Post by perossichi »

I use a stainless D shackle available from a marine supply store or amazon

Something like:

https://www.amazon.com/Stainless-Steel- ... V94SX6DW94

The bolt the goes across the gap in the “U” and thru the hole right above the tail skid. The shackle has to be wide enough to fit around that part.

I then use a carabiner to attach to the tie down chain (thru a link in the chain) for transient tie downs.

Works great and doesn’t scratch the finish on the tail plate. Probably will hold a Gulf Stream down but it looks great. Will try to send a picture.
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