Show Me Your Hangar Floor Tail Anchor

MBDiagMan

MBDiagMan

Final Approach
Joined
May 8, 2011
Messages
5,200
Location
Mount Pleasant,Texas
Display Name
Display name:
Doc
I have need to put the Mooney on jacks. I have the jacks on the way, so now I need to lag an anchor point to the hangar floor. My thinking is to over engineer it by about five to one, but that is a side comment.

Show me what you used in your hangar floor. I would like to find some standard hardware piece of some sort. I will use flush mount lag nuts, so I can remove it when no in use to eliminate a trip hazard.

Thanks!
 
I don’t have a hangar, but I think if I needed to do what you’re doing I would fill a 5 gallon bucket with cement and put an I bolt in it.
 
MBDiagMan said:
I have need to put the Mooney on jacks. I have the jacks on the way, so now I need to lag an anchor point to the hangar floor. My thinking is to over engineer it by about five to one, but that is a side comment.

Show me what you used in your hangar floor. I would like to find some standard hardware piece of some sort. I will use flush mount lag nuts, so I can remove it when no in use to eliminate a trip hazard.

Thanks!
Click to expand...

I'll take a picture of mine this afternoon when I'm back from flying and post it here.
 
either a 5 gallon bucket or the bottom portion of a drum that has cement in it that resides on one of those furniture movers that has 4 wheels on it so it easily slides around or under a bench.

-Paul-
 
Metal rolling mop bucket filled with quick-Crete and an eye bolt sticking up in the middle. Make sure the shank is deep and put a couple large washers on it to prevent pull out.
 
Half a 55 gallon drum filled with concrete on roller wheels. Not a fan of holes in the floor unless they are going to a drain system.
 
For something like a Mooney or Cherokee you don’t need a lot of weight on the tail. The Cessna 210 on the other hand where you raise the wheels 17" from the ground requires a different approach. We put two bolts in the floor and hold the jack stand down with a 1/4" thick metal bar. Then we put 400 lbs of batteries on it and about 40 lbs of weight in the center.


TailStand.jpeg

We drilled a hole in the stand for a bolt since it can slip out of the divots.

TailStandBolt.jpeg

And because we are paranoid, we use an engine hoist to make sure the plane doesn’t drop on the nose.

EngineHoist.jpeg
 
I have used what they call “drop in anchors” for lagging in concrete. This makes for a female flush nut flush in the concrete. Unscrew the bolts when the tie down is not in use. When needed again, bolt the plate or whatever back in place.

My hangar is 60 x 60. My planes and my son in laws 172 are in there along with a road vehicle or two in different places at different times. Leaving a weight in the same place all the time gets in the way of the hangars flexibility. Having a smooth floor anchor in the position I use for maintenance with a removable plate with a smooth floor when not in use is what will work best for me.
 
MBDiagMan said:
you used in your hangar floor
Click to expand...
If you own the hangar a purpose anchor as you described will work, but most public owned hangars usually dont allow such mods.

I had a concrete filled, wheeled tub that would adapt to any aircraft and i would loan it to anyone. But had one customer who modified an old fuel bladder tank and we'd fill it with water when needed. Full it would weigh 800lbs.
 
Something to consider - if you're installing the drop in anchor (flush nut in the floor), keep it filled with a short bolt/cap screw when you're not using the big eye bolt. That will keep it from filling up with crud and or damaging the threads.
 
I have four drop in anchors that I use for another purpose. When I set them, I put them deep enough in the floor for a bolt head to sit flush. When the fixture is not in use and the bolts in place it is almost a smooth floor. You can roll a heavy toolbox over it and you can’t tell that it’s there.
 
the best way is when you pour the floor put one in using a sprinkler valve box set in before the pour.
 
I drilled two 1/2" holes completely through the 3.5" slab about 4' directly to the side of the tail tiedown ring on both sides of the empennage. I drilled the holes at a 45 degree angle, drilling inward toward the plane. I bought two 1/2" x 12" steel eyebolts at Lowes (couple of $ each), and these slide right into the holes I made in the slab floor. I have two 1/4" cables, one each going from each eybebolt to the tail tiedown. Centered on each cable is a turnbuckle for fine adjustment. The eyebolts slip in and out easily and stay with the jacks. My plane (177RG), like the 210 needs to get the tires at least 20" above the ground before swinging them.

It's important to keep yawing in check when your plane is up on jacks, and either a cement filled bucket with an eyebolt type of rig, or a jack as JScarry describes, is necessary. A cable or chain straight up from the floor doesn't hack it. My two cables keep the plane from yawing around and don't take up much room in the hangar.
 
Capt. Geoffrey Thorpe said:
How much force is applied to the anchor?
Click to expand...

Probably two or three hundred pounds, but I’ll engineer it for five to ten times that.

The idea of one anchor on each side rather than a single one in the middle sounds good to me.

I was hoping to find some standard hardware items that would speed up the project. Fabbing up something will take time elsewhere doing the cutting drilling and welding.
 
MBDiagMan said:
Thanks Mike, but I don’t want something else to have to store when not in use.

...
Click to expand...

Mine is a tripod tail stand, so does not meet your criteria.
I always want a rigid connection to the tail so it cannot go up or down. I am on and off the wing of the Aztec numerous times when it is on the jacks as I have to use the manual hydraulic pump to raise and lower the gear.
 
I bought a $10 HF furniture dolly and four big concrete blocks (about $3 apiece at Lowe's). Screwed some 3/4" plywood to the dolly, drilled it in the center and installed an eye bolt, and set the blocks on the plywood. Then, it's just a matter of cinching the tail down with your favorite ratchet strap. Nice to be able to easily roll it to the corner of the hangar when not in use.
 
JohnAJohnson said:
I drilled two 1/2" holes completely through the 3.5" slab about 4' directly to the side of the tail tiedown ring on both sides of the empennage. I drilled the holes at a 45 degree angle, drilling inward toward the plane. I bought two 1/2" x 12" steel eyebolts at Lowes (couple of $ each), and these slide right into the holes I made in the slab floor. I have two 1/4" cables, one each going from each eybebolt to the tail tiedown. Centered on each cable is a turnbuckle for fine adjustment. The eyebolts slip in and out easily and stay with the jacks. My plane (177RG), like the 210 needs to get the tires at least 20" above the ground before swinging them.

It's important to keep yawing in check when your plane is up on jacks, and either a cement filled bucket with an eyebolt type of rig, or a jack as JScarry describes, is necessary. A cable or chain straight up from the floor doesn't hack it. My two cables keep the plane from yawing around and don't take up much room in the hangar.
Click to expand...

So John, how big is the plane you use this setup on? My Mooney, when on its gear, has the rear tie down point about 28” above the floor. I am thinking it needs to be about 8” or 10” higher than that when on the jacks. It would seem that 48” to each side would be a shallow angle. I am thinking that about 3’ to either side would give about a 45 degree angle. Since you have done this before, is there a reason you have a shallow angle, or maybe you have a taller plane.

Thanks for taking time to describe your arrangement.
 
MBDiagMan said:
So John, how big is the plane you use this setup on?
Click to expand...

This setup if for a Cessna 210. The bottom of the wheels are 17" above the floor so it gets exciting if you don’t have the plane stabilized. I don’t know exactly how high the tail is but I’d guess that the tail is about 36-40" from the ground.

I use the same setup for my Cherokee and for a Comanche—but they are only a few inches above the ground so we don’t need the engine hoist. The tail is probably 24" above the ground with them.

My previous mechanic didn’t mind the instability—but maybe he has better insurance than my current mechanic.

Cessna 210 on Jacks.jpeg
 
Furniture dolly with a 30 gallon galvanized wash bin. Put a piece of 1" pipe with a piece of rebar through the end of it in concrete. hato a hole in the other end with a telescopic pole in it that I can put a bolt in to lock in place.
 
Creekrat said:
either a 5 gallon bucket or the bottom portion of a drum that has cement in it that resides on one of those furniture movers that has 4 wheels on it so it easily slides around or under a bench.

-Paul-
Click to expand...

This is what my AP has and he just rolls it out of the way when not in use. Since you don't want to store anything, can you just take it outside and ratchet strap the tail to a tie down on the ramp somewhere?
 
Thanks for the ideas, but I don’t think I want to leave my newly painted, beautiful airplane setting on the ramp. I have a very large, fabulous hangar. One of the reasons I have a hangar is so that I can do maintenance and leave things apart if necessary, out of the weather, behind lock and key. The ramp doesn’t meet that criteria.

I have enough room to store some contrivance, but I don’t want anything unnecessarily accumulating. Things will accumulate enough as it is.

My plan is some D rings tied to the floor with drop in anchors. When not in use, I will have an Allen head set screw in place to keep out dirt and prevent a trip hazard.
 
Doc,
The wing jack pads sit 88" off the floor when jacked, and the tail tiedown ring is 48" off the floor when the aircraft is jacked. For a low wing which doesn't require space between the tire and cement, I would think 3' should be plenty. Problem with the Cardinals is that the mains come downward and inward before going back into the wheel wells, so the bottom of the tires have to be 20" above the cement before swinging them.

I'd send you some pictures but the plane is in the paint shop for at least another couple of weeks.

MBDiagMan said:
So John, how big is the plane you use this setup on? My Mooney, when on its gear, has the rear tie down point about 28” above the floor. I am thinking it needs to be about 8” or 10” higher than that when on the jacks. It would seem that 48” to each side would be a shallow angle. I am thinking that about 3’ to either side would give about a 45 degree angle. Since you have done this before, is there a reason you have a shallow angle, or maybe you have a taller plane.

Thanks for taking time to describe your arrangement.
Click to expand...
 
Thanks a bunch John! I got the D rings positioned three feet either side of the tail. I used a plumb bob on the rear tie downto position it directly over the center point between the D rings.

I got two pieces of chain, removable links and turnbuckles. I plan on giving the chains enough slack for the rear to be three inches higher than it is now then begin raising the wing jacks until they are three inches higher. Hopefully this will give adequate clearance under all three tires.
 
This worked great! I started raising the plane. When the tail starting getting a little tension one side, I adjusted the turnbuckle on the slack chain until it was about the same tension. I then raised the plane until I could fit a 2x4 block under each wheel. I then swung the gear and all worked well. Once chains were removed, you have to know where the anchors are located or they are unnoticeable. I am very pleased with this setup.

Thanks John!
 
Very nice Doc. I admit I also use a third cable straight down, but I really like the dexion piece you're using. I think I''ll borrow the idea Thank you.
 
I have already put away the jacks and chains. I should have taken a picture first. I will try to remember the next time it’s on the jacks to take pictures. Hope it’s not any time soon. The annual is next month, but Maxwell is doing the first annual as part of the purchase deal, so it will be on jacks in his hangar not mine. If it is on jacks before next years annual it will be because I’m having trouble of some sort.
 
You must log in or register to reply here.
Back
Top