The "BEST" tie downs

[logjam]

I could be the most unskilled pilot out there and If I made good decisions I would never put an airplane at risk. That includes choosing how and where to tie down an airplane, and when to move it out of a bad situation. High on the list of decision making assets is local knowledge. That’s why employers and insurers place a high premium on Alaska time even though alaska time is no guarantee of good decision making.
Some places in Alaska the big winds always come from the same direction. Other places as the low passes the wind shifts all the way around the compass rose. This Thread brings back memories of one storm out west where another member here and I spent the night moving our cubs into the wind. By morning our two cubs were the only ones on the field without our wings lying on the ground, including the guys that used the two by four method of lift strut protection.
In other places moving my airplane out from being downwind of under secured airplanes saved my bacon several times. I did that in anticipation of weather events. Couldn’t have moved once they started.

[Ed Ruebling]

Logjam,

Some very good thoughts. I'm on floats now so along those same lines, multiple ropes, attachments to solid parts of the aircraft, on floats not just the float cleats but around the strut attachments to the floats, on the wing a loop through the wing struts.
When I tie-down on water I look at which way the winds are blowing and think about what might happen to the airplane if a strong gust came along. Ideally I'd want it to turn into the wind if possible yet not travel down the shore and hit another airplane.
I use duckbills on shore, a line from the float strut in to shore, a line out to the back of the floats on each side with separate anchors for each.
I can loose 2 or 3 of these lines and still hold the plane at the tie-down.
Its also helpful turning the plane around since I can go different directions depending on the wind. It always wants to weather vane into the wind so use it to your advantage.

[DavePA11]

Where does one buy the duckbills tie downs with the wire to pull them out? Thanks.

[stewartb]

In the Anchorage area we have multiple dealers. Elsewhere? No idea. And FWIW, you don’t pull them out. You might dig them out but I don’t know anyone who would. Use them and leave them.

[mvivion]

Where does one buy the duckbills tie downs with the wire to pull them out? Thanks.

Here: https://www.amazon.com/s?k=duckbill+earth+anchors&adgrpid=58883126874&gcl id=EAIaIQobChMIqprBkZjg4wIVUxx9Ch1LQA9SEAAYASAAEgJ 5n_D_BwE&hvadid=274839608079&hvdev=m&hvlocphy=9021 324&hvnetw=g&hvpos=1t1&hvqmt=e&hvrand=700099299060 5914554&hvtargid=kwd-302450881565&hydadcr=12162_10197798&tag=hydsma-20&ref=pd_sl_7bcm47x9h1_e

Or, they are commonly used to guy power poles, etc. so an electrical contractor store.

Ive seen them at Lowe’s also.

MTV

[Chicken Hawk]

Where does one buy the duckbills tie downs with the wire to pull them out? Thanks.

I’ve never seen the 2 wire duckbills for sale anywhere. Most people add the second wire themselves. Just drill a hole in the longest part of the open end & install your own pull wire. You can get them to come out in softer soils.....not so much in tight compacted earth.


Sent from my iPhone using SuperCub.Org mobile app

[algonquin]

The company’s that sell the tarp covered buildings sell them, Shelter lodging I think is one.

[Chicken Hawk]

Anybody tried these?

4'' Earth Anchor (4 Anchor Set) W/3/16'' Cable Assembly https://www.amazon.com/dp/B07BWSSFQ2..._d2HqDb2F4MEJM


Sent from my iPhone using SuperCub.Org

[DavePA11]

Thanks for all the feedback. So even Amazon sells them without the retrieval wire that people add, and from Stewartb the #68 is the correct size. I can see now how this could be an issue at airports on grass for mowers if used for a lot of planes and not retrieved.

https://www.amazon.com/Pack-Duckbill...gateway&sr=8-1

[stewartb]

In soft soil you can drive 68s with a piece of rebar but in stubborn soils the tempered drive rod is worth having. Rebar will fold up when the ground is hard. The drive rods are very tough, even against glancing blows from a tired old man.

[DavePA11]

I could be the most unskilled pilot out there and If I made good decisions I would never put an airplane at risk. That includes choosing how and where to tie down an airplane, and when to move it out of a bad situation.

Logjam - I think having the weather smart apps help in forecasting the bad weather to make those decisions. Much harder in the past without them. IMO.

[55-PA18A]

[QUOTE=Chicken Hawk;751654]Anybody tried these?

4'' Earth Anchor (4 Anchor Set) W/3/16'' Cable Assembly https://www.amazon.com/dp/B07BWSSFQ2..._d2HqDb2F4MEJM


These look interesting. Reviews indicate they work well in rocky soil. The aluminum duck bills don't do so well in rocky soil.

[JWE]

Anyone have any experience with the Big Screw tie down system? They claim 1200 lbs per screw.

https://www.youtube.com/watch?v=eW7vG7Qwmnc

[Lotro]

I'm late to the party.
I thought Lift Spoilers were the way to go in high winds... someone once suggested strapping a few pool noodles to the leading edge. Or is the concern too much wind on the rudder?

[DENNY]

They do help I have a set of mesh covers with lift spoilers on them, but you still need a good tie down when the wind blows hard.
DENNY

[BC12D-4-85]

Spoilers on top of the wings help reduce overall lift but there's still some wind that pushes on the wing's bottom and tail. Swirl's around and buffets the entire plane. If there's loose snow blowing the wind's pattern can be seen. Solid covers unless vented or made of mesh will blow up off the wings and can damage the trailing edge and controls by getting too tight. Cessnas and others can end up with bowed tops to the ailerons as a result of that wing cover tension.

Gary

[stewartb]

New improved Duckbills.






Sent from my iPhone using SuperCub.Org mobile app

[BC12D-4-85]

The design's stepped end mimics some of the newer ice spuds used to open holes for fishing. They gradually penetrate hard surfaces rather than the whole end trying to go though all at once.

Gary

[Doug Budd]

Had my pacer tied down in Dickinson ND with heavy duty racket straps. The forecast was calling for 70mph wind with higher gusts. Made me nervous so I bought some rope and double tied all three corners. Glad I did wind blew at 90 degrees and two straps failed the rope saved my plane. Now I don’t use straps, they start to fray then tear


Sent from my iPhone using SuperCub.Org

[BC12D-4-85]

Unless twisted along their length flat straps will flutter and can fail.

Gary

[Gordon Misch]

Yah, like Tacoma Narrows Bridge - ha!

Shanghai Tower (super-tall) has a twist to it, supposedly for that same reason (vortex mitigation). https://www.google.com/search?q=shan...QL0Ex73P695SM:

[BC12D-4-85]

Von Karmen shed vortices are a contributing factor.

Gary

[RVBottomly]

Unless twisted along their length flat straps will flutter and can fail.

Gary

Right. I learned that from hay truckers long ago.

[hotrod180]

….. The tail tie down failed because I had it fastened to the tail spring loaded handles. The 60+mph first gust ripped the eye off of the handle leaving the claw in the ground. When the plane spun 180 into the wind, it pulled up the Wing Claws. …...

I've seen this kind of thing in different type of failures,
most notably, a scaffold-- one support was hit by a truck and collapsed,
bringing down the whole structure.
It was fine, however, until that first support was damaged.
I'm curious why you fastened to the eye(s) in the pull handles?
Do you not have the eyebolt where the tailwheel assembly attaches to the stinger?
That, or the t/w fork or head itself, seems to me to be the best attach point(s).

[TurboBeaver]

Dont forget a very important factor to holding a Cub in winds in excess of 50kts is the flimpse piece of channel that conects your spar to your strut is the fuse........ Hundreds have failed over the last 65 years. The best ropes and tie downs are useless to you, when this part fails. Atlee has two different cures. Either modify yours or its simply a matter of time before you
will learn the hard way........

Sent from my LM-X210 using SuperCub.Org mobile app

[Tnathan]

Hello,

Interesting thread. I was curious if there is a final ranking AV consumer didn’t test the claw that I use.

I bought a claw based on recommendations, but I thought I heard that at SnF it was a claw on the husky that flipped. Could be wrong.

Abe’s looks like a cool design. This is new to me.

My wife use to use a dog tie out auger. She said it is cheap and hasn’t let her down yet. Then again she hasn’t tested in some of the winds you all are talking about.


The duckbills looks light and easy but I wonder about cost. I suspect I would lose these over time so they could end up costing more than the other options.

I wonder if some work better in different soils clay versus sand. Anyone pick their tie down based on the soil they are expecting. I ask because I thought augers are the least strong, but one of the comments above said they use an auger for Sandy soil? Should I throw my wife’s augers away or do they have a purpose for some soils?

Secondly. I didn’t understand about the pool noodles to break air flow or a spoiler. Sounds interesting but I can’t visualize how these would get attached. My fear is they will come partially loose and whip the wing all night. Anyone have a picture?


Sent from my iPad using Tapatalk

[Colorguns]

Sewed a 9-10” sleeve on top at the crown of the wing. Insert the noodle then put the wing cover on the wing. Takes about 6 minutes each to install. Haven’t done thieves lot and sure it will go fast with practice.
this is what Turbobeaver is talking about.

[DENNY]

I buy duckbills 30 at a time so I get a bit of a discount. I make up sets of 3 and put in plastic ziplock bags. The final cost is 25 dollars a set, I use 1-3 sets per year. The cost is nothing compared to that damage that could be done if the wind comes up. YOU GET WHAT YOU PAY FOR when it comes to anchors.
DENNY

[BC12D-4-85]

If using dog rope augers try putting two or three (best) in at each wing or tail tie down. Screw them flush with the ground and spread them out in a triangle a couple feet apart at least. Connect them with rope or cable from each to a flat central point in the middle of the triangle. Tie your ropes or cables to that point - a heavy steel ring makes a good attachment. If the wind blows the rope to the wing or tail being pulled up will try to pull the three anchors sideways towards each other and not as much up. They'll hold better under a side than a vertical pull.

Gary (uses duck bills and ice screw anchors plus wing spoilers)

[StalledOut]

For us with floats..........one big advantage to duck bills is you can drive them into a lake or stream bottom.
If the wind comes up and you're on a beach with the floats rocking back and forth against the bottom or shoreline go drive some duck bills in deeper water and pull the plane off the bank and tie it down faced into the wind.
Can't do that with other tie down systems.
I am with Denny, the cost is cheap. And they flat out work.
Just make sure you have a good driving rod and that's long enough.

[stewartb]

I've had no luck with Duckbills in water saturated soils. FWIW.

[aktango58]

I've had no luck with Duckbills in water saturated soils. FWIW.

we got between 1,500 and 1,800 pounds on a pull test in saturated sand (glacier till) when we did our pull test with them. To get that we drove them four feet into the ground, which is not practical without having machinery to drive them. Not much will hold in saturated soils, no matter what you do. A sheet of plywood buried would be your best bet there.

[StalledOut]

Huh, I've not had any problems other then them eventually rusting. I have them in Lake Spenard, in Shulin Lake and even had some in the mud on the Deshka by the ADF&G cabin (adjacent to the island). All those have held over the years. The only place they wouldn't work would be the pond at the Kustatan. Not much works there when it's wet.

Since the dock floats and is 64 feet out in the lake I use them at the end with a chain to keep the dock straight. No pipes or posts sticking up to hit that way.

I guess I've just been lucky.

I don't use the tiny ones, I use the medium sized ones that AIH carries.

[RaisedByWolves]

Where do you guys buy the duckbills from?


Sent from my iPhone using Tapatalk

[DENNY]

Arctic wire and rope is the best price I have found in Anchorage. If I was in the lower 48 I would do amazon.
DENNY

[BC12D-4-85]

Full size ducks in wet soils or underwater are the best unless electrical pole tie screws are used. It takes 3' or more and even then a railroad jack can slowly pull them out...side loads are best so don't install them vertically under the tie down locations. Most up loads are not a steady pull and use two or more spaced apart for best strength. Stainless cable lasts and doesn't corrode. After years and galvanized can rust out at the thimbles if the water/upper bottom soil interface goes anoxic and low pH sulfide compounds create acids.

Gary

[Skywalker]

Why so little interest in tail stands? I would think the first thing would be reducing wind load in the first place. Perhaps a more easily stowed post guyed 3 ways.

[Steve Pierce]

Hello,

Interesting thread. I was curious if there is a final ranking AV consumer didn’t test the claw that I use.

I bought a claw based on recommendations, but I thought I heard that at SnF it was a claw on the husky that flipped. Could be wrong.

Abe’s looks like a cool design. This is new to me.

My wife use to use a dog tie out auger. She said it is cheap and hasn’t let her down yet. Then again she hasn’t tested in some of the winds you all are talking about.


The duckbills looks light and easy but I wonder about cost. I suspect I would lose these over time so they could end up costing more than the other options.

I wonder if some work better in different soils clay versus sand. Anyone pick their tie down based on the soil they are expecting. I ask because I thought augers are the least strong, but one of the comments above said they use an auger for Sandy soil? Should I throw my wife’s augers away or do they have a purpose for some soils?

Secondly. I didn’t understand about the pool noodles to break air flow or a spoiler. Sounds interesting but I can’t visualize how these would get attached. My fear is they will come partially loose and whip the wing all night. Anyone have a picture?


Sent from my iPad using Tapatalk

I was at Sun & Fun and I don't think anything would have saved some of those airplanes short of a few box vans blocking the wind.

[Steve Pierce]

Where do you guys buy the duckbills from?


Sent from my iPhone using Tapatalk

Tractor Supply here has them.

[mvivion]

I've had no luck with Duckbills in water saturated soils. FWIW.

I used them as tiedowns in Fairbanks for ~ twenty years IN the float pond, to secure Cubs and Cessnas up to 206 on floats, and on shore on wheels. They were in there for years. After ten years or so, i augmented the early ones that had galvanized cable with ones with stainless. But, after twenty years the ones with galvanized cable were still stout.

These went through some pretty serious gusty winds from T-Storm outflows. Which also creates wave action, to work against the anchors. I never gave a thought to whether they’d hold, there was never a doubt.

MTV