Van's Air Force

The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!

Tiedowns

The Big Screw kits with straps have open hooks. No way Jose. That's just stupid. Like Bob said, use closed carabiners, or tie a knot in a rope.

View attachment 89443
My tiedown carabiners are rated for 24 kilonewtons (almost 6,000 pounds) and weigh 32 grams each. Probably stronger than "just strong enough" .

Can't assess the strength of the snap hook on the other end of the Big Screw tiedowns, but I might put a carabiner there as well.

Great hint about using two tiedowns for the tail of an A model. Guess I'll be making a fourth one.

Additionally, I secure my RV-6A with the elevator centered and the flaps up. Don't want it sitting there in soft field takeoff configuration.
 
I looked all over but I couldn't find that video. It would make interesting viewing, although I'd factor in that it was clearly not an unbiased experiment. I find it odd that they would break where the spikes go through, as the weak point seems to be where the arms pivot about the center, which is why they are intended to be installed vertically.

This gives rise to a question- how strong do tie downs need to be? I'm no engineer, but I understand the concept of "just strong enough" and wonder how that would apply in this case. Any stronger than "just strong enough" is just extra weight to be carried around. So, how strong is "just strong enough?"
I think technique has a bigger part than how strong in many cases. We had an F1 microburst blow through our airport 2-3 years ago. Maybe 50 planes on the ramp, but only two got damaged. A maule had only tied down the wings and not the tail. It was found upside down in a heap. The action of the movement with no tail security was enough to rip one of the 5/8” 12 braid ropes off one of the wings. The other was a long ez and it had its tie down rings ripped out of the wings. It was thrown against a fence 10’ away.
 
I put together a simple set of tie downs.

20' stick of 3/8" rebar from the local masons supply yard. Had them cut it into 6 pieces 40" long each. $6.50

Bent them into U shapes using a pair of 5' long 3/4" steel pipe. I primed them to avoid the oxidized steel from getting on everything.

Pounded 2 in each tie down at a 45 degree angle.
Joined them with chain quick links, to avoid stressing my carabineers.
IMG_20250714_134640090_HDR.jpgIMG_20250714_133846311_HDR.jpg
IMG_20250718_200437582.jpgIMG_20250714_134823474_HDR.jpg

Getting them out, there is plenty of surface area to tug on. Any long lever can be slipped under the U, to lever the them out of the ground.

No welding, and only needs a heavy hammer to install.

So simple even I could make and use them.

Chuck
 

Attachments

  • IMG_20250718_200437582.jpg
    IMG_20250718_200437582.jpg
    5.7 MB · Views: 27
I loath chains. They are damaging on more than one level. Not only with the hammering action with no give as their slack bangs in and out in the wind. If an aircraft is tied down for an extended time with chains that same rocking action can cause brinelling of the wheel bearing races as the rollers are worked back and forth. If I have to use a permanently installed chains on pavement or cement I will pull out my ropes and clip into or tie into the chain close to the anchor point and then use the ropes to tie the airframe. Since the ropes can be tensioned when tied (unlike straight chains) the small portion of chain used is part of the system an also properly tensioned.
 
Here's one I saw just yesterday, a variation on the one described in #31 and Simple and inexpensive.
IMG_20250830_175143717_HDR.jpg
 
I bought a set of 3 walmart doggie tie downs last year for SNF. They worked without issue but we didn’t have any monster weather events that really tested them either.

When I read about the doggie tie outs breaking, I researched the options to replace them. Everything was bigger, heavier, more expensive, and when each was tested they had various issues.

The doggie tie outs have great holding capacity compared to the overpriced over engineered aircraft solutions except they have 2 problems:
1: they can snap off where they were crimped
2: the handle can bend open.

I had a buddy weld up my doggie tie outs by welding up solid the weaker crimped area and welding the handle closed into a solid loop. I will tie my rope through the loop/handle IMG_8065.jpeg
Mischief managed.
 
Drill more holes in the Aluminum angles, you may want the vertical option for some soils, but if parking first it is too hard to install under the wing.

The 45 degree angle for others, with all the hold downs pounded in buried tips toward the tie down at a 90 degree angle. Switch the open hook for a closed device or knot and double up the attachment with a half loop anchor of round steel U-bolts

I use "titanium" 14 inch long camping stakes.
 
Except for the hook - that can get expensive, when it opens up. Assuming the hole doesn't rip out first.

Dave
Good points. I may make me a set with the U-bolt in there to replace my current setup which is the 2 crossed-tubes and spikes which work well outside of T-storm country but otherwise probably need an upgrade.
 
I’ve got a set of the Claw tiedowns and after reading all this I’m thinking I should invest in either the Stormforce or the Flyties. One better than the other?
 
Here's one I saw just yesterday, a variation on the one described in #31 and Simple and inexpensive.
IMG_20250830_175143717_HDR.jpg

That's a fantasy tiedown. Not enough spikes, and as pictured, 12" nails stuck halfway in the ground are useless. And it's the vertical-pull type. If pulled at an angle, as it seems in the photo, two of the stakes are being pulled tangent to their axis, and the other two are not at 90 to the pull.

ScreenHunter_2935 Sep. 02 08.28.jpg

A Chinese dog tie, "fixed" by welding, complete with slag holes and grind marks? Tell us you're not serious. You just didn't want your Pekinese to get away, right?
 
Ha! Dan, you're right!

I was looking at the structure and missed that the little tacks aren't doing much.

Dave
 
That's a fantasy tiedown. Not enough spikes, and as pictured, 12" nails stuck halfway in the ground are useless. And it's the vertical-pull type. If pulled at an angle, as it seems in the photo, two of the stakes are being pulled tangent to their axis, and the other two are not at 90 to the pull.

View attachment 96514

A Chinese dog tie, "fixed" by welding, complete with slag holes and grind marks? Tell us you're not serious. You just didn't want your Pekinese to get away, right?

EAA (Experimental Aircraft Association)tie-downs use stakes and have performed well in tests, holding only 400 pounds before failure in one case.
The claw failed at 650 pounds of force in suitable soil,
Any of the systems that use a straight peg need to have a longer rod, driven into the ground and need to pull at an angle to be effective.

Aviation Consumer test found that a spiral "doggy" auger resisted 575 pounds of load Before the head deformed! so take away the 2 possible failure points for the Pekinese tie down and its actually a viable solution.
 
Don't forget that different soils will hold differently. Out West, some rocky sandy places will be difficult.

Dave
 
This is why I carry the $40 in 1998 Titanium version of screws for everywhere but big fly ins. Light and they work, but look like dog stakes to the unwashed.

I made a set of StormForce lookalikes for beating back the masses.
 
I had a set of the Titanium spirals (the good ones made for aircraft) and ended up selling them. Because half the time or more, they just didn't work in whatever soil type there was. Perhaps I was hasty in doing that (and, it was before this whole discussion). Anyway driving in spikes (to their full depth) has always worked better for me in most soils and "seems" more solid than I could usually get the spirals.

All of that said, the Big Screw product looks pretty compelling!
 
I don't have a picture of them at the moment, but I made my own tiedowns by cutting 3 pieces of 6"x6"x3/8" steel plate, drilled three holes in the plate out near the edges, and welded a single chain link in the center. I run the big 15" steel tent spikes down through those three holes (at an angle to each other, not all straight down) with a good hammer and use a heavy ratchet strap to the airplane. It has weathered many storms in Oshkosh and S'n'F without even beginning to budge, even when other airplanes around me were torn loose and moving around. Sure there are lighter versions of these on the market, but the capacity of these tiedowns are rated "P", for "Plenty". This way Dan doesn't get to yell at me. I even welded my tailnumber into the top of each plate so nobody got tempted to borrow one. :cool:
 
Bumping this thread. We’re getting close to that time of year! Please be responsible with your tie down choices!

I used the Big Screw system at OSH ‘23, backed up with the ultimate gust lock from AntiSplat, backed up further with the flight control locks on the ailerons and elevator (those red clamp style ones from AS). No issues with the windy storm that came through that year (45+ gusts).
 
Bumping this thread. We’re getting close to that time of year! Please be responsible with your tie down choices!

I used the Big Screw system at OSH ‘23, backed up with the ultimate gust lock from AntiSplat, backed up further with the flight control locks on the ailerons and elevator (those red clamp style ones from AS). No issues with the windy storm that came through that year (45+ gusts).
Oshkosh had a front come thorough last week with 90 MPH gusts on the field. THAT would be a problem for any of our tie-down systems. But more and better ropes, anchors and gust locks are always helpful The first thing to do is make sure the tail is tied down well. If the airplane starts to weathervane, the rest of your tie-downs won't do much good. I think this year I'm taking two tie downs for the -10's tail. gonna stake one apiece slightly behind and to the side of the airplane to better secure the tail against sideloads/weathervaning.
 
Oshkosh had a front come thorough last week with 90 MPH gusts on the field. THAT would be a problem for any of our tie-down systems. But more and better ropes, anchors and gust locks are always helpful The first thing to do is make sure the tail is tied down well. If the airplane starts to weathervane, the rest of your tie-downs won't do much good. I think this year I'm taking two tie downs for the -10's tail. gonna stake one apiece slightly behind and to the side of the airplane to better secure the tail against sideloads/weathervaning.
When at parking at OSH, I tend to have TWO tiedowns on each wing, at different angles, and two on the tail. Airplanes are made to FLY, as we all know! Can one be TOO safe? One predicable thing about OSH weather is that it will be unpredictable!!
 
When at parking at OSH, I tend to have TWO tiedowns on each wing, at different angles, and two on the tail. Airplanes are made to FLY, as we all know! Can one be TOO safe? One predicable thing about OSH weather is that it will be unpredictable!!
I believe the best way to reduce the possibility of damage is to tie-down facing WEST! For whatever reason, most airplanes are parked facing East, but most gust fronts come from the West. Even with good control locks, a strong gust from the rear has a better chance of causing tail damage than if the plane is facing the wind. Ask me how I know. BTW - the parking guys allow you to park facing any direction, as long as you stay “in your box.”
 
I believe the best way to reduce the possibility of damage is to tie-down facing WEST! For whatever reason, most airplanes are parked facing East, but most gust fronts come from the West. Even with good control locks, a strong gust from the rear has a better chance of causing tail damage than if the plane is facing the wind. Ask me how I know. BTW - the parking guys allow you to park facing any direction, as long as you stay “in your box.”
Having volunteered at OSH since 1987, all but that little break we had for some virus something, I can vouch for gust fronts coming from ALL points of the compass. Seems like the strongest come from the North, but it depends, of course, on where the storm is that it is coming from. Do storms usually come from the West? Yes; but a storm originating in the West now sitting North of the field can generate gusts going SOUTH. I have many memories of sitting in my tent with the North wall bulging in! :oops: :oops:

I believe The North 40 all park facing West or East, depending on how one gets tailed in. Vintage and South 40 are all facing North. No choice as that is how the parking lines are laid out. Homebuilt is different.

The Big Deal is (and we say this EVERY year) TIE YOUR AIRPLANE DOWN!! (Sir, you need to tie your airplane down. Yeah, I know. I'm just going to registration. Good. That can wait. Please tie your airplane down now.) Sigh...........
 
Back
Top