DIY Tail Tie Down Weight For Servicing Nose Wheel / Strut

Sinistar

En-Route
Joined
Sep 9, 2016
Messages
3,712
Display Name

Display name:
Brad
TLDR: A set of weights on a jack. Used tent weights vs workout weights to save a crap ton of $$$. See pictures below if interested.

Our new AP managed to service our 182 strut better than the last mechanic and I thought it would hold out all winter but the nearly -30F evenings the past week or so finally had its way and the 0.000000001 cubic inches of nitrogen finally leaked out :( So gonna need to shift gears and solve that problem...when its warmer. However, I got sick of placing sandbags or cases of oil on the tail and home brewed up something simple to pull the tail down.

For the 182 you need around 170lbs of weight on the tail if the nose strut it fully collapsed. Or you can put about 120lbs on the tail and push it the rest of the way down where it will stay due to the larger angle on the plane. I was never comfortable with placing that much weight on the surface of the plane so decided I am going to use the tail tie down instead. Here were my goals:

1.) Be able to move the weights without having to lift them
2.) Use just enough angle on the plane for the nose wheel to come off
3.) Find a cheap source of weights (exercise weights is pushing $3/lb up here!)

So the first part is easy. Having the weights on a floor jack means its easy to move around and easy to lift up and down.

As for the angle it just took some trial and error to find the distance of the tail hook to the ground. The reason I don't want it all the way to floor (maximum angle) is that the nose goes up so high its hard to reach down in and air up the strut.

Cheap weights were the most difficult part. Then one day on CL I found this guy selling off tent weights. Never even knew there were tent weights. Anyhow, these were $1.20 a pound and interlock! Each half is 30lbs. So three full disks are 180lbs.

The last step was to either fabricate a holder or buy something. When looking at exercise equipment I soon noticed there are Kettlebells handles. Funny aside - always thought they were called kettle balls. The kettlebell kit came with (2) full assemblies and a empty one is also shown in the last picture. The base of the kettlebell handle fits perfectly in the cup of the jack. About $40 for these two units. I did cut a 2x8 just long enough to sit under the weights at a 90deg angle to the split for a bit more stability. So if we don't count my 30yr old jack, about $190 for everything else. Using work out weights would be $400...$550. If you already have the weights you could do it for $40.

Disclaimer: I am well aware of the tail tiedown arguments for/against pulling(winching) it or placing weight on it.

20210220_161319-2.jpg

20210220_161935.jpg

20210220_161242.jpg
 
My A&P uses weighted sand bags on top of the horizontal stabilator and that seems to work well.
 
Disclaimer: I am well aware of the tail tiedown arguments for/against pulling(winching) it or placing weight on it.

I'm not sure what the Cessna maintenance manual states but the Piper manual says to place a weight on the tail tie down and jack up the wings until the nose gear comes up.
 
Last edited:
We did something similar—a cart with weight in it—to get our Skyhawk in and out of a 1930s hangar built for a taildragger (low door).
 
I welded up a frame made of 2 x 2 x 1/4" steel angle. Welded four sturdy casters to it. The frame held two cylinder heads off some massive old engine, perhaps a big genset or something, heads that weighed at least 150 pounds each. Big cast iron cubes, basically. The frame held them about six inches apart, and there was a pulley attached to the frame between them, down low, and a boat trailer winch off to one side that fed a rope through the pulley, with a hook on the rope. This thing would pull a tail tiedown ring almost to the floor.

Don't have pic of it. Left it behind ten years ago. Cylinder heads like that would be rare anyway.
 
Nice job!

I drilled, concrete-anchored, and put an eye-bolt into the hangar floor just under the rear tie down. I use sand bags to get it to where I can easily push down and then tie/hook the tail down.
 
Nice job!

I drilled, concrete-anchored, and put an eye-bolt into the hangar floor just under the rear tie down. I use sand bags to get it to where I can easily push down and then tie/hook the tail down.
Mine was moveable because I was in a hangar with eight airplanes and had to look after them all. Moving them around just to get the tail over a floor-ring would have been a pain. The concrete anchor is a really good way to do it in a one-airplane hangar. One could mount a boat trailer winch on the rear wall, running the rope out to a pulley that hooks into a ring screwed into the anchor. I never liked putting a lot of weight on the stab; it can deform the skins and underlying ribs. The weight required to pull the tail down is a lot more than normal air loads, since the wing's CP is much closer to the CG than the main wheels are, and the air loads are spread across the entire stab, not concentrated in a small area.

Of course, a taildragger eliminates the hassle entirely.
 
My A&P uses weighted sand bags on top of the horizontal stabilator and that seems to work well.
for the past two years i have been using (3) 60lb sand tubes so probably similar to your AP. But I figured I more likely then a AP and wrinkle or screw something up hence the switch away from that method. Your AP definitely understands the weak areas better than me.
 
We did something similar—a cart with weight in it—to get our Skyhawk in and out of a 1930s hangar built for a taildragger (low door).
its crazy how tall the tail is when the nose strut is fully deflated. And when pulled down my wife can change the tail beacon light bulb.
 
Nice job!

I drilled, concrete-anchored, and put an eye-bolt into the hangar floor just under the rear tie down. I use sand bags to get it to where I can easily push down and then tie/hook the tail down.
Eventually we are going to put a winch at the back of the hangar to pull the plane in. Was thinking of a eye bolt in the floor that I could attach a pulley onto for pulling the tail down. But then I started thinking ill trip over it. Or accidentally apply full winch force. Then we started pulling the plane into the new hangar nose first so the floor hook became less relevant. Once we have the hangar finished out we will probably stick to just one direction LOL!
 
Eventually we are going to put a winch at the back of the hangar to pull the plane in. Was thinking of a eye bolt in the floor that I could attach a pulley onto for pulling the tail down. But then I started thinking ill trip over it. Or accidentally apply full winch force. Then we started pulling the plane into the new hangar nose first so the floor hook became less relevant. Once we have the hangar finished out we will probably stick to just one direction LOL!
The floor anchor could be a threaded thing, and you could unscrew the pulley hook when you're not using it.
 
Eventually we are going to put a winch at the back of the hangar to pull the plane in.

My hanger has this. Someone prior to me installed it to pull a taildragger in. It’s an electric winch centered at the back of the hanger with a remote. I’ve never hooked it up to an airplane because we already have a bat operated tug. Guessing it’d work well. Are you planning to use it for a tricycle gear?
 
its crazy how tall the tail is when the nose strut is fully deflated. And when pulled down my wife can change the tail beacon light bulb.
Yup! It also gives you a different sight picture when the nose strut is inflated vs when it’s not.
 
My hanger has this. Someone prior to me installed it to pull a taildragger in. It’s an electric winch centered at the back of the hanger with a remote. I’ve never hooked it up to an airplane because we already have a bat operated tug. Guessing it’d work well. Are you planning to use it for a tricycle gear?
Yes, for tricycle gear. More of a pita pulling in by tail but would be awesome to pull in by nose.
 
Four 50# fertilizer bags stacked at the root of the horizontal stabilizer of my C210D work just fine. I would be unsure of the tiedown ring pulling 200#. Since my fertilizer bags are also stored in the hangar it's quick and cheap.
 
Four 50# fertilizer bags stacked at the root of the horizontal stabilizer of my C210D work just fine. I would be unsure of the tiedown ring pulling 200#. Since my fertilizer bags are also stored in the hangar it's quick and cheap.
That ring has a 5/16" shank on it, and it's made of a good steel. If it was the same as AN bolts it's good for 125ksi. Lets be conservative and assume 100ksi; the area of that bolt is good for a 7700-pound pull. Take off a bit for the thread depth and we're still left with 6180 pounds of tensile strength.

Based on the way it can be bent 90 degrees when someone strikes the tail, and it doesn't break off, I'd say its the same nickel steel as the AN bolts. It's not just cheap Grade 5 carbon steel. Cessna uses a longer version of that bolt on their struts as tiedowns, too, and that bolt is part of the collection of fasteners that hold the machined strut end in the strut. It carries some of the airplane's weight. And it has to withstand its share of the lift generated in a windstorm.

There's an aftermarket stainless eyebolt for the Grumman tails. It's not PMAd. Same size as the Cessna bolt. The sellers claim they've put over 2000 pounds of pull on it with no deformation. Consider that stainless is softer and weaker than nickel steel.
 
Last edited:
why do we go through this ever 6 months to a year? unless the manual says stack sh...t on your horizontal, thats not the way to do it. simple, use the procedure called out in the maintenance manual. lots of good ideas here, using weight on the tie down as called out in most manuals.
 
The floor anchor could be a threaded thing, and you could unscrew the pulley hook when you're not using it.

I had a hardpoint like that in the back of my garage/shop that I could use as a change of direction to winch a dead or engineless car up the slight incline in the driveway. It was a threaded insert that was anchored in a 1/2in hole drilled into the concrete. When not in use it was plugged flush with the ground using an Allen head bolt.
 
Last edited:
That ring has a 5/16" shank on it, and it's made of a good steel. If it was the same as AN bolts it's good for 125ksi. Lets be conservative and assume 100ksi; the area of that bolt is good for a 7700-pound pull. Take off a bit for the thread depth and we're still left with 6180 pounds of tensile strength.

Based on the way it can be bent 90 degrees when someone strikes the tail, and it doesn't break off, I'd say its the same nickel steel as the AN bolts. It's not just cheap Grade 5 carbon steel. Cessna uses a longer version of that bolt on their struts as tiedowns, too, and that bolt is part of the collection of fasteners that hold the machined strut end in the strut. It carries some of the airplane's weight. And it has to withstand its share of the lift generated in a windstorm.

There's an aftermarket stainless eyebolt for the Grumman tails. It's not PMAd. Same size as the Cessna bolt. The sellers claim they've put over 2000 pounds of pull on it with no deformation. Consider that stainless is softer and weaker than nickel steel.
It's not the bolt. I did study stress analysis. But I was thinking about the aluminum sheet metal that the bolt attaches to. In any case stacking the bags takes only a couple of minutes and it's gloriously low tech and the bags are free and only 15 feet away.

On to something more interesting like dark matter, dark energy and multiple universes.
 
It's not the bolt. I did study stress analysis. But I was thinking about the aluminum sheet metal that the bolt attaches to. In any case stacking the bags takes only a couple of minutes and it's gloriously low tech and the bags are free and only 15 feet away.

On to something more interesting like dark matter, dark energy and multiple universes.
The bolt doesn't just go through the sheet. It passes though an extension of that cast-aluminum aft bulkhead, the same one that carries the horizontal stabilizer's main spar and the vertical fin's aft spar. It's sturdy stuff.
 
Back
Top