The "BEST" tie downs

[mvivion]

Being one of those who was affected by the Anchorage windstorm a few years back, I'll offer my experience. My cub was tied down (Merrill field) facing generally away from the wind. When the wind blew, it was mostly from the rear slightly quartering from the left. The tie downs and wing attach points stayed attached, but both rear struts buckled and the wings were bent forward. The elevator hinges were also cracked and I had to replace one elevator. I had spoiler wing and tail covers on at the time.

Those aircraft tied nose into the wind on other rows were mostly undamaged. Given a choice, I'd tie down facing the wind. Of course, the conditions I experienced are unusual (103 mph winds), but it was a learning experience. During the rebuild, I installed (in addition to one new wing) heavy duty lifetime struts and Atlee Dodge tie downs and spar reinforcements. Given a choice I'd still tie down facing the wind (and probably elevate the tail to kill lift).

What he said ^^^. When I lived in Kodiak, I spent a lot of quality nights baby sitting airplanes tied down at Municipal Airport. When it was windy, I’d drive to the airport, and frequently check tiedowns, chicks, etc on my personal and assigned planes. While steady winds can be bad, it’s often the gusts that cause real problems. One night as I checked on my plane, I noticed a Super Cub next to it, with rear struts start to buckle. I got under the wing and tried to hold it, when a city cop came by, and called the owner. Rigged 2 x 4s on aft struts, wrapped with line.

Was too too windy to risk turning it around. Plane was damaged, but not too bad.

Living and working in Cold Bay and Kodiak taught me more than I ever wanted to know about big winds.

Given the choice, I will never intentionally tie an airplane down facing away from the wind. Sometimes we don’t have a choice, but airplanes and their structures simply were never designed to sustain forces from that vector.

But, like a lot of things, tail into the wind works right up till it doesn’t. But when things fail, it gets ugly quick.

And it’s often the gusts that bite you.

MTV

 

[stewartb]

Being one of those who was affected by the Anchorage windstorm a few years back, I'll offer my experience. My cub was tied down (Merrill field) facing generally away from the wind. When the wind blew, it was mostly from the rear slightly quartering from the left. The tie downs and wing attach points stayed attached, but both rear struts buckled and the wings were bent forward. The elevator hinges were also cracked and I had to replace one elevator. I had spoiler wing and tail covers on at the time.

Those aircraft tied nose into the wind on other rows were mostly undamaged. Given a choice, I'd tie down facing the wind. Of course, the conditions I experienced are unusual (103 mph winds), but it was a learning experience. During the rebuild, I installed (in addition to one new wing) heavy duty lifetime struts and Atlee Dodge tie downs and spar reinforcements. Given a choice I'd still tie down facing the wind (and probably elevate the tail to kill lift).

My 180 took that storm from the right rear. I watched the struts buckle on the Cub next to me and another up the row. I watched a PA-11s struts buckle in a different storm with much lower winds. Last summer when my Rev was parked outside I preferred the wind to be quartering on the nose. Nose to the wind would pull much harder on the ropes. Slat wings make tying down even more important. They want to fly! Things we learn.

 

[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.....

Did I read this correctly, that you tied down to the eyes in the tailcone-mounted pull handles?
Curious why you would choose to do this, rather than tie down to the eyebolt at the tailwheel
(assuming you have one), or to the tailwheel assembly itself.

 

[schnell49]

Hypothetically speaking, if you had only a set number of weight to tie down to in the backcountry, obviously a sh!t ton would be ideal—

but how much weight would be minimal per wing if you could only tie down to an object? 100lbs? 500lbs? Assume for this question airplane is positioned correctly, ropes are correct strength etc etc

I’m not asking about the 1% (“rogue wave” etc)—but maybe wind/gusts up to say 45mph


thx

 

[DENNY]

My cub will fly all day with a 1,000 lb + load at 45 mph. Start from that and go up.
DENNY

 

[algonquin]

In Seldovia one of the local guys brings a tractor trailer to the airport and sets it blocking the main wind direction. Then most guys here bring a vehicle out and tie to them. We get lots of high winds here but the old dodge hasn’t moved yet.were lucky that we can do this, the wind in the 60’s -80 happen in the fall and winter most.

 

[hotrod180]

My cub will fly all day with a 1,000 lb + load at 45 mph. Start from that and go up.

I've seen a number of guys tie their airplanes down to a 5 gallon bucket full of concrete, that weighs maybe 100 pounds?
Always makes me wonder what they're thinking.

 

[BC12D-4-85]

A local did the heavy bucket thing. Spring gear 140 that rocked enough to get the buckets swinging. I heard they moved some and damaged the plane but were removed by the time I got to the airport to look. Doesn't blow much here unless a thunderstorm or dust devil gets legs.

Gary

 

[john schwamm]

Stewart,
One summer I had a Helio on floats tied down on beach on Iliamna Lake, Kahkonak bay, venuturi effect through Pile Bay slot, it blew so hard it lifted one float out of the water. Slats were going in and out, and they do that flying at about 55mph, the plane was tailed up on beach and pretty level flight attitude. Sitting in it wind was steady indicating 60 MPH and gusting higher. Had to sink some 55 gallon drums in the lake to tie to to keep the Helio from levitating! Wind blew for over 5 days. Did not get much sleep, cabin was moving non stop.
John

 

[BC12D-4-85]

Wind Story: Kodiak's Red Lake outlet 1970. PA-18 doing salmon surveys landed in windstorm expecting worse yet to come. We (summer temp fish counters) were tasked to fill the floats with buckets of water as nothing to tie to nearby. Blew and rained for three days pilot said 50-60 on his AS and was the reason I assumed the cabin had cables over the top for anchors. When it quit we (us temps again-plane crew were supers) pumped and dipped out what we could then drug and pried the plane up on shore to empty the underwater portions.

Gary

 

[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&gclid=EAIaIQobChMIqprBkZjg4wIVUxx9Ch1LQA9SEAAYASAAEgJ5n_D_BwE&hvadid=274839608079&hvdev=m&hvlocphy=9021324&hvnetw=g&hvpos=1t1&hvqmt=e&hvrand=7000992990605914554&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.


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[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/ref=cm_sw_r_cp_api_i_d2HqDb2F4MEJM


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[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-Duckbil...earth+anchors&qid=1564615940&s=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]

Anybody tried these?

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






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[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


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[BC12D-4-85]

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

Gary