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Tie Down Kits

s10sakota

Well Known Member
Surely this topic has come up before! Using the search function, I can only find threads on baggage tie downs, and rope vs rachet threads.

I bought a Cherokee 160 to fly while I build my RV-7 so I need to purchase a tie down kit.

Obviously, I'd like to have something simple and lightweight, yet strong.

So, any thoughts on tie down kits? From searching the internet, one guy says Brand X is the best tie down kit ever, and then another guy chimes in with a picture of the same tie down kit that broke in a light wind! Looking for thoughts and opinions on different kits available.

(or please point me to known threads that I may have missed)

Thank you.
 
I bought the Stormforce tiedowns often recommended in here. They certainly seem like they will work well, and reviews of those using them in the great tornado fiasco of sun n fun past are good. The customer service of Stormforce leaves quite a lot to be desired though (order them months before you need them) and frankly I'm a bit embarrassed I didn't just build my own set. The aluminum angle, U-bolt and the spikes can all be had from Home Depot aviation and the rope too for that matter.

Spend an hour making a set, or spend two months waiting for them...either way I think the Stormforce tiedowns will work as well as any and better than many.
 
Lowes

Go to Lowes Aviation dept. and get 3 of the pre cut 2 ft 1/2" or 5/8" rebar and some strong rope roll up in a towel or find a bag to carry it in with a hammer now that you are a homebuilder this is how we roll and it makes just about the best tie downs money can buy. Don't forget to put them in the ground at an angle away from what you are trying to hold down.
Bob
 
I use a couple of stakes that pass through a block of aluminum to which I tie the rope. The 2' stakes need to be driven in with a hammer.

Simple.

The main thing - tie the ropes very tightly, no slack, to prevent the plane from moving.

Dave
 
Our EAA Chapter is selling some ....

Surely this topic has come up before! Using the search function, I can only find threads on baggage tie downs, and rope vs rachet threads.

I bought a Cherokee 160 to fly while I build my RV-7 so I need to purchase a tie down kit.

Obviously, I'd like to have something simple and lightweight, yet strong.

So, any thoughts on tie down kits? From searching the internet, one guy says Brand X is the best tie down kit ever, and then another guy chimes in with a picture of the same tie down kit that broke in a light wind! Looking for thoughts and opinions on different kits available.

(or please point me to known threads that I may have missed)

Thank you.

See below.
Helps our EAA Chapter.

They are based on a design that held my plane through the hurricane at SnF a few years ago.

Contact Mike.
===========================
Need a tie down kit?
EAA 242 Fundraiser: Tie Down Kits Available
If you are planning to go to Oshkosh this July, or some other destination where you will need a tie down kit, EAA 242 has four tie down kits ready to go.

Each kit includes everything you need to tie down anywhere. The kit includes:

1 each 14" bag to hold all the items
1 each extra 12" bag for tools
3 each 12-foot braided ropes rated at 396 lb. each
3 each UHMW tie down puck assemblies
9 each 12" x 3/8" steel spikes
1 each Standard 16 oz. hammer
1 each Scotch Brite cleaner pad
1 each Carabiner puck/pad keeper

All net proceeds go to EAA Chapter 242. We have sold six kits so far. Thank you to those who bought the kits! After expenses approx. $20 goes to the chapter for each kit.

We have four kits ready to go. They are $75 each. First come first serve. If you need to have your kit shipped, please add $12 for USPS Priority Mail. Otherwise we will make arrangements to have them at the SAC for pickup.

Please email me at: [email protected] to make purchase arrangements.

Thank you!
 
There was a long thread of posts here in the forums that year after the tornado hit Sun N Fun. I just don't remember which year it was! :eek: Search a little more and you'll find more designs...and more opinions! :eek:
 
I got mine

I bought a kit from Mike. I haven't had the opportunity to use them yet, but it is a nice kit. Thanks, Mike and EAA Chapter 242.
 
There was a long thread of posts here in the forums that year after the tornado hit Sun N Fun. I just don't remember which year it was! :eek: Search a little more and you'll find more designs...and more opinions! :eek:
Here is a thread on the SnF tornado and tie downs:
http://www.vansairforce.com/community/showthread.php?t=70490&highlight=sun+fun+tornado

Found the above by doing a search on Sun n Fun tornado and got these results:
http://www.vansairforce.com/community/search.php?searchid=21329603
 
That EAA 242 tie down kit description worries me. From experience, I know that 12" stakes aren't long enough for many types of soil, and the ropes need to be at least 700 to 1,000 pounds strength.

Dave
 
I bought some materials from Home Depot today and made my own tie downs. They 'seem' very strong with me pulling on the rope, but I guess they will need a real life test. Obviously I got the design idea from the Storm Force tie downs.

The only 'problem' now is that I could only find 12" stakes and I'd like to get 18" ones. I'll try few other local places. The eye bolt is 1/2".



 
Tie down

Mark
I like that one. I'll bet if you drive two in the opposite direction, it would be very hard to pull it out.
 
Mark, the eye bolt can have a similar failure mode as the cheap screw-in tie downs, where the eye hook portion simply un-folds and lets the rope slip right off. Your design is a lot stronger than the screw-in style, of course, but a quick and simple tack weld where the eye hook turns back to almost touch the shank will increase strength of the hook substantially. Just an idea...
 
Mark, the eye bolt can have a similar failure mode as the cheap screw-in tie downs, where the eye hook portion simply un-folds and lets the rope slip right off. Your design is a lot stronger than the screw-in style, of course, but a quick and simple tack weld where the eye hook turns back to almost touch the shank will increase strength of the hook substantially. Just an idea...
Or use a U-bolt instead.
 
I also thought about having a welder close the opening in the eye bolt. An buddy of mine has a welder so I'll take them over and have him close them up.

My original plan was to get a steel U bolt, but none of them matched the hole layout in the steel angle so I had to go with the single eye bolt.
 
I also thought about having a welder close the opening in the eye bolt. An buddy of mine has a welder so I'll take them over and have him close them up.

My original plan was to get a steel U bolt, but none of them matched the hole layout in the steel angle so I had to go with the single eye bolt.

So that's a 1/2" eye bolt?? Talking diameter of the rod or the hole in the middle. Either way, I'm betting you could lift a small car before opening that eye bolt... Check before all that effort.

If you just have to close the eye, look at these first. http://www.mcmaster.com/#eyebolts/=sci5u6

Also, what's the load limit on your ropes? You might be surprised if you're just using twisted nylon, etc. I just ordered some new braided poly from Amazon. (Man, I love that one-click Amazon prime!)

I am warming to your idea of using the angle. Thanks for sharing!
 
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The rope you see in the pic is "airplane tie-down rope" that I ordered from Sporty's.

I will admit that it looks a lot like clothes line rope though. I probably won't be using it to tie the airplane down and will try to find some better rope. But for now it's all I have around so I tied it up and pulled like heck on it! Even with the 12" stakes the tie downs didn't budge!

(wow I like the eye bolts in your link! I may order three of those!)
 
The rope you see in the pic is "airplane tie-down rope" that I ordered from Sporty's.

I will admit that it looks a lot like clothes line rope though. I probably won't be using it to tie the airplane down and will try to find some better rope. But for now it's all I have around so I tied it up and pulled like heck on it! Even with the 12" stakes the tie downs didn't budge!...
Might be good stuff. Some of the premium (sailing, boating) ropes can be good for 1000+lb at 3/16" diameter. Would just be good to know before making all the other links of the chain significantly stronger.
 
$25 at Lowes

I held myself and the cub that lay against me at RnP with the simple chain and Caribiner method. Learned from the thrifty guys at the Cessna 150 Club.
 
Homemade Tie-Down Kit

These are my homemade tie-downs. The red base pieces are some predrilled steel angle material - each about a foot long. I had a scrap piece of this; it is available at any hardware store. 1.5? by 1.5?. Cut with a hacksaw and edges smoothed. A 4 foot piece sells for about $11.
http://t.homedepot.com/p/Everbilt-1...n-Zinc-Plated-Slotted-Angle-800517/204225758/

The u-bolts are 5/16 inch diameter and cost a dollar apiece. Got the width to match the holes in the angle. The angle iron and u-bolt assemblies weigh 12.7 oz. each or 2 lb 6oz total.

The 12 inch galvanized stakes were 70 cents each. They are slightly less than 0.5 inches in diameter and I had to enlarge the selected 4 holes in each angle iron for them. Total weight of 12 stakes is 4 lb 7 oz. Aluminum ones would be lighter, don't know how they would hold up.

The one-inch ratchet straps come from USCargoControl. They are rated at 3,300 pounds each breaking strength (tested for weakest component), 1,100 pounds each working strength. Six foot length (10 foot or custom length available) with snap-type hooks on each end. They cost $33 total for 3, including delivery. Each weighs 1 lb 5 oz for a total of ~4 pounds

The nice carry satchel was a typical symposium giveaway; similar bags are at flea markets for about a dollar. Weight 8 oz.

Total weight is 11.25 pounds (plus a hammer!)
Total cost was about $42 not including the angle iron.

IMG_0033-small.jpg
 
Recommendation for that - ditch the straps and replace them with 3/8" polyester rope and learn a couple knots. It'll be lighter and easier to adjust.

A good place to get rope (they call it line or cordage) is www.apsltd.com.

You can even step down a size on the rope.

Dave
 
Screw in blade type anchor testing

Hi All,

I finished my propeller install for the last time the other day, but I had one last task for the engine hoist before I return it to its owner. That task was validating the pull resistance of the screw in anchors I purchased.
Bill R. mentions an avweb anchor analysis in his post. Avweb actually have two videos of anchor testing, however neither test reviewed the blade-type screw in anchor (only the corkscrew anchor).
https://www.youtube.com/watch?v=UIuYK_eEQ9c
The anchors I purchased were sold as trampoline anchor set of 4 for just under AUD$30
http://www.lifespankids.com.au/ANCH...MI2Y_I2rSM2gIV2CMrCh0s8gKLEAQYAyABEgJz8_D_BwE
The anchors appear to be hardened and heat treated steel (the heat treatment marks are still evident on the eye, and approximately 12" in length.
52m13l.jpg

Since I had 4 anchors, I though I'd sacrifice one and do a pull style test like the Avweb lads, setting the test up per the photo below.
The ground was slightly moist sandy red soil, as I was trying to emulate the conditions that the avweb team utilized. The anchor was easily screwed in using a 5/8" OD pipe of 12" in length.
20u6fy8.jpg

On the first pull, the metal buckle fractured at 170lbs. I then tied the straps and tried again. On the second pull, the ground in a radius of about a foot around the anchor began to lift in a dome shape. As I reached maximum load, the anchor began pulling a core of material out of the middle, and the load on the digital scale began dropping. The maximum load achieved was 305lbs, almost identical to what Avweb achieved with all the other dedicated tie down kits.
6gynm9.jpg

At maximum load there was no opening of the eyelet and upon removal, the cutting edge and rod in general appeared to be in excellent condition.
If I had an aircraft of larger wing area or very light weight or was expecting a severe storm, I think I'd be using two of them per wing, with the rope tied to one, up over the aircraft attach point, then back down and tied off at the second, but with approximately 1.5-2ft between the two anchors, as it seems to lift the entire ground around it as I mentioned previously.
I weighed the anchors, and they came to 230g each, including the tie down straps. If you assume you need 3 of these, plus a 12" long 5/8" OD pipe (200g) plus a carry bag, the total is coming to around 900g, or 2.2lbs. To put this into perspective, by the time I added the hammer and bag to the "Claw" tie down set, it was significantly more than the claimed 8 lbs, for almost exactly the same tested load in sandy soil. Oh, and they retail price of the claw here in Australia is $225, almost 8 times the price of the trampoline anchors.
Anyway, I just thought this might be of use to people out there looking to get a set of tie downs anchors.
Tom.
 
Good for, you doing some testing to evaluate performance but to find out what the maximum attainable performance of a single stem screw in tie down is, you need to test it in a manner that would copy using it correctly.

Your test didn't do that.

I often see people using screw in tie downs in a manner that will put the primary pull load straight up on the anchor (they screw it straight into the ground directly below the tie down point on the bottom of the wing..... bad idea).

The proper way (and the way Paul tried to simulate in the avweb video) is to position the ground anchor so that when finish, it is screwed into the ground at about a 45 deg angle with the rope perpendicular to the ground anchor and traveling up to the wing bottom ring at about a 45 degree angle.

This creates a load vector that is trying to pull the ground anchor sideways, vs straight up out of the ground. If you did a test pull in this manor, I am sure the load would be higher.

An additional key to performance is getting it screw full depth into the ground (if at all possible) which will aid in preventing it from being pulled sidways.
 
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Good call Scott. I pulled vertically because I thought this was going to be the most conservative, and I didn't like the idea of trying to pull at 45 degrees on a hoist I had borrowed (I was worried about damaging the sketchy castor wheels). Thinking about it now, if I put the hoist up on blocks and pinned it with some steel posts, this would be a non issue. I should re-run the test at 45 degrees, but frankly, I really must finish this RV-7 first, because I don't have far to go (hence the reason I'm testing tiedowns).
Tom.
 
http://www.flyties.com/index.html

I am using these. They are simply to use and the only thing I carry along with them in a rubber malet.
I just moved back from living nine years on the island of Utila in the NW Caribbean. I used these tie downs on an asphalt ramp. They worked fine for me with my BN 2 Britten Norman Islander. No direct hurricane hits but some serious close calls and they held well. Did not try to remove them. Only complaint is be careful to hit the head of the spike straight on. Anything else broke the head off but the "puck" was not affected. I left them in the asphalt when we sold our charter airline. I would buy them again. BTW, I upgraded the line due to the weight of the Islander to 3/4" line and used bowline knots to secure the line to the ring in the puck. Makes removal of the line much easier. Especially after a blow.
 
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