The International Cessna^® 170 Association

Anyone here in 170 land ever use Duck Bill earth ancors for tieing down a plane?
What size?

http://www.youtube.com/watch?v=ZAb-rIkUrME

Bill

Yeah, I use them up here when I leave the plane on a hunt and I can't find any better tie downs. I think mine are about 4 inches long, but I don't have them in front of me to measure. Takes a bit of effort to drive them in heavy, rocky gravel, but once they are in, they are really, really in! My plane has been in some big wind tied to these, and I don't worry about them at all.
KW

KW it doesn't seem that you could get these out. Is there a trick way? Or are these permanent type tiedowns.

My thoughts were kind of the same as KWs comments. Looks great till you hit that boulder just under the surface.

I'm in Alaska and also use the duckbill anchors for off-airport tiedowns. I think my anchors are 4-inch and they have a 18-inch tether cable. I carry a 24-inch bar to drive them in with and turn the bar sideways through the eye in the tether to "set" the anchor. I use an army trenching tool to dig them out. They've been recycled several times and are still in good shape but I have had occasions where I had to try several times to drive them into rocky soil.

Bill

Thanks guys,

Without a jack hammer, I assume most anything is hard to hammer into rocky ground.

Didn't think about digging them out. I have two locations where I want them permanantly. Besides rocky ground, they look easy to put in for their holding capacity. And besides the 1/2 inch rod and hammer, they are light weight.

Bill

Bruce, the best trick to remove them, is to hand your hunting partner the shovel and tell him to start digging out the anchors, while you "check the CG" and pace off the gravel bar, just to make sure!

Really, sometimes you just have to leave them in place for the next year.

I think I'd put a rope protector thing in the eye of the cable if I was going to use them with rope for long term use. I'm sure there is a name for the teardrop shaped piece of metal I'm thinking of, but I can't for the life of me think if it!

Others?!!!
KW

It's a Thimble.

Probably needless to say..... be certain the ropes you use are as up to the task as the anchors and the airplane's lifting-capacity!

zenpilot wrote:...I think I'd put a rope protector thing in the eye of the cable if I was going to use them with rope for long term use....

If the duckbill device comes with a loop already installed on the cable end, a thimble will be hard to add. Those need to be installed when the loop is initially swedged. If the loop is already there without a thimble, a carabiner between the loop and the rope would work better, IMHO.

These duck bill tie downs are similar to the anchors I use for traps and snares. They can be removed by not seating the anchor when they are initially placed in the ground. What I mean is dont pull up on them to cause the anchor to turn sideways. Then tie the plane down without much tension on the ropes. If a wind comes up and puts tension on the anchor and sets it. Then it would be a good idea to tighten everything. If it stays calm and no tension develops on the ropes the anchors can easily be removed. Put the bar back down the hole to engage the anchor and pull up on the wire. The bar prevents the anchor from seating as it is pulled out. I use this technique trapping and have not yet had an anchor not seat when a critter applied the tension. It is not always possible to engage the anchor when putting the bar back down the original seating hole so some will just be lost. Look for these in any trapper supply website or just make your own they are relatively cheap. I believe these are amazingly capable devices. Caught a badger once and it appeared a 500lb bomb was dropped at the trap site. This badger dug up so much dirt the crater he created was large enough for me to get in. The anchor had only about 8 inches of soft dirt left over it and held up to that. That was a 3 inch anchor. A 4 incher would be very sturdy. Steve

Thanks Steve, never considered buying them from a trapping supply store.
But, maybe found a little better ancor from Minnesota Trapline Products.

http://www.minntrapprod.com/catalog/ind ... 09_293_503

I think these will hold better because they are finned and they are removable. They are 3.75" to 4" long
and they added a retrieval boss to pull them back out. I don't have any dreams that they will pull out easy, but
at least it has an eye for a second cable or wire to help retrieve it.

I ordered a dozen 18" finned super stakes for $29.95 and the stake driver for $7.45. I'll add three carabiners like John suggested, or chain links, and I believe these will make very effective and relatively inexpensive tiedowns.

Looking through trapping websites makes me want to run a trap line again. Besides mice, raccons and skunks its been 25 years since I did any serious trapping. Just looking through the websites gets me motivated.

Bill

Good luck Bill. The funny thing is I have had many concerns about tie downs and then read your post. Never even thought about these anchors. My hangar is full of all my trapping supplies and not 4 feet from my plane are 30 of these anchors. The solution was right under my nose and I never saw it. Thanks Steve