I'd like to find a functional, convenient tiedown/anchor system to use in typical backcountry airstrip surroundings. One product that looks good on paper is "The Claw" (http://www.aircraftspruce.com/catalog/pspages/claw.php), which is sold at Aircraft Spruce for just under $100. It appears to be lightweight, and sounds like it should work OK on any natural surface except rocks.

Anybody have any pireps on this product?

Or anyone with other product recommendations?

How about this system..homebuilt...20", 1/2 " rod with two chain links welded on them..pound them into the ground at an angle with the hammer..tie the rope off at a 90 deg angle..to pull out, tap withe the hammer sideways to loosen...pull straight out. Been using these for years.

The claw has its good and bad points.

First, if you're going to use a stake or set of stakes for your connection to the ground, then you need to ensure that the load on the tie-down rope is pulling sideways on the stake, not straight up. The claw is a compromise in this regard. They aren't applying 90 degree load on the stakes, it's more like 60. They mitigate that problem to a degree by using three stakes for each tie-down. Because each of the three is pointed in a slightly different direction, they tend to handle a gusting wind a little better where the plane will rock back and forth, tugging on the rope. There is also some degree of redundancy, because if one starts to work loose, the others might still hold.

The problems with the claw are as follows:
1) The rigid nature of the claw doesn't give you the ability to move just one stake if you hit a rock while driving the stake. You have to move the entire claw and try again.
2) The stakes are too short, too narrow, and too close together for sandy soil.
3) A hatchet is a better choice than a hammer.
4) The cost is high for what you are getting.

If you like the claw, you can make a much better version yourself for a whole lot less money. Go buy a 20 ft. chain and a couple of speed links at Walmart along with a hatchet and some big tent stakes. Total cost will be about $25 to $30. Cut the chain into 2 foot lengths. Attach three of the chains together with the speed link and spread them out like the claw. You will have a 4 foot diameter circle, unlike the 1.5 foot diameter circle of the claw. If you put a stake at the three free ends of the chain slightly angled toward the center, the forces on the stakes will be much more horizontal when pulling up in the center than they are with the actual claw. If you hit a rock with a stake, you can just move that chain end a little bit and try again. If you are anal, you can drive multiple stakes along the chain. I use this system myself, and it actually weighs a lb. or two less then the claw system, while providing a slightly greater holding force.

If you love the brute force approach, hicountry's solution looks great. The biggest problem with it is that the stakes have to be longer because there is only one at each tie-down point, and you might have trouble driving them in rocky ground as deep as they need to go. Also, people will poke fun at you for compensating for something when they see you carrying that hammer! It sure looks nice and simple once you get it welded, although I'm curious what it weighs. Make sure you have long tie-down ropes so that the stake is far enough away to put a sideways load on it.

Finally, you will be amazed at how many times you can trip over the same tiedown gizmo when you're camping under your wing. Fluorescent orange paint might be a good idea!

Some derivative with stakes having large enough end plates or pads (that you can kick down in the ground with your foot)... might allow you to not carry the weight of the hammer. Especially in sandy soil.

The stakes could be a piece of sharpened angle iron, with a large "fender washer" welded on the other end - that is large enough to push with a shoe.

Kevlar or Spectra of the right weight can save weight over chains, is non-corrosive and non-conductive in a storm. t also will yield a bit under load, so you don't shock load the airplane in a gust.

Most back country pilots are always trying to save weight. Having a lighter design like this could either reduce the overall weight of the tiedown kit. Or it could allow more or bigger tiedowns for the same weight.

hicountry wrote:How about this system..homebuilt...20", 1/2 " rod with two chain links welded on them..pound them into the ground at an angle with the hammer..tie the rope off at a 90 deg angle..to pull out, tap withe the hammer sideways to loosen...pull straight out. Been using these for years.

I've only had one place where I could not drive these rods into the ground, that was Magee airstrip. The ground must have rock under a shallow dirt surface. I tried many different locations around the plane. I usually drive the rods in just to the loops, attach the nylon rope, and then drive the stakes in so just the tops of the loops are showing. There is no way the rope will come loose. To remove, just hit the stake sideways a couple of times and pull it straight out..never had one stuck in the ground.
I have tried several sizes of rod up to 1" and the 1/2" seem to work as good as any and they are less weight. As far as the hammer, I used to carry a 16 oz ball pien but it was harder to hit the stake. I have seen the "Stake " used and in sandy soil I'm not impressed. As you see in my picture I carry 4 rods and I also carry 4 ropes just in case 3 won't do the job.

I make my own back country tiedowns . Easy with a lowes or Home depoet in area. Or send me 40 bucks and I'll make them up for you. Go to Lowes or such and get 3 concrete stakes I think there about 18" long about 1-1/2" wide by 1/4 -3/8 " thick. Go to hardware section and buy some of those 3 inch carabeiers with screw together lock. Go to rope section and get some 35 ft. of 5/8" nylon rope -head for home (don't forget a 1/2 " drill bit ) ----- go out to your trusty "man cave" and drill your concrete stakes center mass 1-1/2" from blunt end (for your carabiners) I cut 2 sections of the rope 14 ft. and burn the ends with lighter and crimp with a pair of pliers . Short section is for tail tiedown . 3-5 pound sledge with tiedowns at 30 degree outboard angle for mains and tail should do fine >drive stake into groind 1/2 to 2/3 . Bang side to side to remove . Mine went all over and worked real good. I have 4 sets down at ranch that have held airplanes down during 60 knot winds. Weigh about 3-4 lbs rolled up in back of baggage compartment .

I posted this same question recently and got a lot of good replies in this thread viewtopic.php?f=13&t=5010&hilit=lightweight+tie+down

I went with fly ties and I broke the head off one of the stakes the VERY first time I used it. It seems to hold well though once you get them all in and it comes with a cool tool for removing the stakes. I suspect the reason I broke off the head is I was wailing on it with the back of a Gerber Hatchet which was really narrow. Once I borrowed a sledge from another guy they pounded right in. The ground was really hard too.

My tie downs are also of the 'home brewed for less than $40' variety. They hold well, travel well, and the price was right. I carry 1/2" mooring rope and several locking steel caribeeners as well as 3 duckbills for emergency situations. All materials available at Home Depot, Lowes, Ace, etc...

1.) 3/16" steel cut to 4" triangles. Drill a hole in each corner, at either a 45* angle, or just oblong the hole.
2.) 5 ea. 3' x 3/8" galvanized rod, cut in half, sharpened on one end, a 7/16" nut welded on the crown.
3.) 3ea. 3/8" u bolts welded in the center of the triangle 'pads'

Gives a bigger 'footprint' than a single stake, and probably doesn't weigh any more since most single stake varieties tend to be 'stouter'. Someone once did a pull test with these, a pull scale, and a cherry picker. I can't locate the info, but it was favorable... Plus it's a satisfying way to kill a rainy afternoon...

Take care, Rob

The Fly Ties kit is very similiar to your set up. It uses a composite disc to guide the three stakes in at an angles. In this months EAA magazine they had some plans for a set up very similiar to this also.

Joey,

I am not all that sharp, I saw someone with Fly ties (didn't know what they were at the time) and thought they looked pretty slick. So I set out to build my own

For the uninitiated, these are duckbills. The tiny ones are 40DB's and have held my cub in decent winds, although I now keep the bigger 68 DB's in both the cub and the 180. I have 88DB's in the Thrush when out of town, they are mammouth. These things weigh nothing, cost near nothing, and are bomb proof, but they are pretty much permanent once driven. Rebar makes a good driver, but for weight factor I took a scrap piece of 4130 and welded a bolt in each end. Sorry, no pics, they are in their respective planes.


You can get them here:
http://www.amleo.com/index/item.cgi?cmd=view&Words=68db

All of these ideas once again prove there's more than one way to skin a cat!!
I like the triangle device..I bet it works well in sandy soil..as I have my own machine shop I way try my own variant of the triangle.
HC

PS: Metal tent stakes also work well if you have enough of them...always carry more than I need for the tent in case I ruin some.
HC

Rob,

Duckbills DO hold VERY well. And, as you said, unless you also carry a shovel, they are pretty much permanent.

AND, if you put a set of those suckers in some groomed airstrip like many of those in Idaho, the guys who mow those strips will strangle you if they ever catch you..... . Those cable eyes will really do a number on a mower blade. Don't ask how the State of Alaska found that out....

MTV

I use a home made set like Rob's and have had good results. Here is a good consumer video on the holding power of a few different types
http://www.youtube.com/watch?v=Loq1olceSIE

One interesting year, I had my duckbills heaved up and out by the frost. It may have been gradual, but they worked their way up to no value and one actually came out under load.

GR

Boy, some people have put a lot of thought and time into designing and building tie-downs! I'm impressed!

It seems that - not surprisingly - the backcountry guys have figured out how to deal with really tough ground conditions ... rocks, etc. ... that The Claw seems not to deal with. Maybe The Claw works good in grassy areas next to developed airstrips, but here in the Rocky Mountains, much more often than not the "soil" is just a thin layer over cobbles.

Looks like home-made is the way to go.

Thanks, guys!

182 STOL driver wrote:I make my own back country tiedowns . Easy with a lowes or Home depoet in area. Or send me 40 bucks and I'll make them up for you. Go to Lowes or such and get 3 concrete stakes I think there about 18" long about 1-1/2" wide by 1/4 -3/8 " thick. Go to hardware section and buy some of those 3 inch carabeiers with screw together lock. Go to rope section and get some 35 ft. of 5/8" nylon rope -head for home (don't forget a 1/2 " drill bit ) ----- go out to your trusty "man cave" and drill your concrete stakes center mass 1-1/2" from blunt end (for your carabiners) I cut 2 sections of the rope 14 ft. and burn the ends with lighter and crimp with a pair of pliers . Short section is for tail tiedown . 3-5 pound sledge with tiedowns at 30 degree outboard angle for mains and tail should do fine >drive stake into groind 1/2 to 2/3 . Bang side to side to remove . Mine went all over and worked real good. I have 4 sets down at ranch that have held airplanes down during 60 knot winds. Weigh about 3-4 lbs rolled up in back of baggage compartment .

I drive these tiedowns in rocky soil like in my little picture near my "182 Stol Driver " -used them in Idaho last summer ,Austin ,Nevada flyin and out at Grand Canyon >>> may or may not be worth 40 bucks to you but they do work under extream conditions.

Portage Creek,

Actually, the holding ability of ANY tiedown is totally dependant on the soil type and characteristics. I had a number of duck bills sunk in and adjacent to the float pond at FAI, and those things were in great shape fifteen or eighteen years later. I finally replaced some of them because I worried they'd rusted out, but they didn't appear to have. None backed out with freezing and thawing, like ever.

But, again, the ability of any tie down to hold is totally dependant on soil type.

What is REALLY important, though, is for the pilot or owner to BE THERE when the wind blows, to tighten lines, to move things, to take care of the airplane. I've seen so many airplanes damaged and a few destroyed that could have been saved had the owner or pilot been there to tend the airplane. THAT is really the key.

MTV

Swingwing wrote:I use a home made set like Rob's and have had good results. Here is a good consumer video on the holding power of a few different types
http://www.youtube.com/watch?v=Loq1olceSIE

Too bad AOPA didn't also test <mobile home or trailer anchors> google words or

ex. http://www.antonline.com/p_59250-GP_344427.htm

It depends on soil type, of course. I've found screw-in augers like these work really well in hard pack sand (dry lake beds), grass, and non-rocky soil. I use a fly tie anchor as well and also carry canvas bags to bury or fill with rocks - - haven't used the bags yet.

AOPA pulled straight up on their tested anchors, but many anchors, such as the augers, do better when the load as at a bit of an angle.

If I was making my own drive-in pin type, I think adding a spade (either welded to the pin shaft or with a channel or tube for the pin to go through) would be a good addition for softer soil. It should provide more resistance to help prevent the pin from pulling laterally through the soil.

Pirep on the "CLAW"

Works great in sandy soil at Mexican Mountain. I was skeptical until I tried to pull them out, but they are the best I've seen. The design makes the stakes dig in deeper when a up load is applied to the rope, unlike all the other designs. Overall rating, I'd say OUTSTANDING!!

Thanks to everyone for sharing their ideas, I enjoy seeing different inventions. I realize soil composition and condition are big factors. Some of the home-made systems appear stronger than the ones on the market. I like the concrete stake idea for people who don't or can't easily have things fabricated and welded.

I've ordered 6 Snowpeak #50 steel stakes -
http://www.backcountryedge.com/snow_pea ... medium=cpc
They are about 18" long with a hook and eye at the top and flat head for pounding. I'll test 2 or 3 driven at angles under the wing and use a steel carabiner or kevlar cord looped through the eye holes for the attach point.

I think something like this, perhaps larger made from titanium would be great to keep the weight down. The longest titanium stakes I've found are small tent stakes about 8" long - and I think a large number would need to be carefully places and equalized. I don't think I'll attempt this.

I have a cargo net for my cub and I've wondered about sewing up something like it only larger using nylon webbing (maybe 1.5" wide) that could be laid out under the wing, then rocks could be piled on it and the net gathered and secured with rope or carabiners. This would be lightweight and require lots of rocks, but not necessarily big rocks. It would take a lot of work.....those duckbills look like good insurance to back up whatever contraption I use when the winds really blow or when I'll be leaving the plane for an extended time.

It seems that the easiest and lightest weight solutions are going to be weaker, with the exception of the duckbills. Not only would the airstrip caretakers curse the bastard who left cables sticking out of the ground, (without attempting to mark it or bury them) but they may also dislike a freshly backfilled excavation left behind after removing them.