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How To Jack Up RV-12iS?

Amadeus

Well Known Member
I found this write up from Vans that says the proper jacking point for RV aircraft is the tie down point: https://www.vansaircraft.com/faq-technical-builder-items/how-to-jack-up-an-rv/

However, with the removable wings, I wasn't certain that this applies to the RV-12. I am adding the wheel fairings to the RV-12iS and need to remove the main gear tires to install the hardware/brackets. Any best practices tips you can share?

Also, it appears the tire assembly will also require removal from the nose gear leg to install the hardware/brackets. Can I jack at the point where the nose gear leg attaches to the fuselage? Any better suggestions?
 
You can push down on the stabilator spar while holding the front of the vertical fin and lift the front wheel off the ground. A helper can the put a saw horse on the rivet line as in the instructions. Then do the reverse and lift at the stab spar and put a sawhorse in the back rivet line.
 
Do not push up down on the stabilator

I may be wrong here if the 12is stabilator and attachment is VERY different from the first generation -12. Or perhaps I’ve misunderstood the advice given about applying pressure on the “stabilator spar”.
With that disclaimer: I’d say DO NOT purposely apply pressure to the stabilator ANYWHERE for and any reason, and certainly not the amount of pressure/weight necessary to raise the nose wheel.
To raise the nose wheel, I use a small step and lay my body over the aft fuse along the bulkhead rivet line just ahead of the vertical stabilizer.
Then my helper positions a padded sawhorse under the firewall rivet line (as I recall) carefully avoiding the antenna near there.
If I need the Main Gear up also, then I position myself beneath a rivet line under the AFT Fuselage and use my legs to push up from beneath. Again, a helper places another padded sawhorse beneath a rivet line/ bulkhead.
The Maintenance Manual page Scott referenced works the best if your floor jack has a cupped lift point so that the Nose Gear Nut can’t slip off, and if your jack is really tall to reach the AFT tie down ring.
2cents,
Dave
 
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I move my RAV-12 around when I don’t have my row bar by pushing down on the fuselage forward of the vertical stab. I would never push down on the horizontal stabilizer. Think about the asymmetric force you apply when you do that.
 
I use the wing tiedown points and a homemade tripod jack for the main wheels. I use a light-duty come-along between the tail tiedown ring and the hangar floor (via a fixed floor point or weighted point) to pull down the tail / lift the nose. Do not press on the stab spar.
 
Not for your wheel fairing project, but this will work if you have to change a tire and there are no sawhorses handy.

jack.JPG
 
Remember that the stabilator is attached to the aircraft with two 1/4 inch bolts. Scares me every time I think about it.
 
With the wings on, these work great. Bottle jack from Harbor Freight.
 

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Not for your wheel fairing project, but this will work if you have to change a tire and there are no sawhorses handy.

View attachment 17130

I'm doing the jacking on Wednesday to install the Wheel Fairing hardware and I plan to use Jon's method. I have the appropriate lumber and C-clamps along with the floor jack to do the lifting.

For the nose-gear riveting, etc. I am planning to use a come-along attached to the rear tie-down to lift the nose then slip a saw-horse across between the steps to hold it while I do the work required for the Wheel Fairing installation.

Unless, of course, I see something that inspires me to try a different method.

Jay
 
Tony,

If material strength is the basis for the concern about shearing a bolt on the horizontal stab attachment I don’t understand why one would worry. Maybe there is something I am missing.

Rich
 
Common tool for “jacking up” stuff.

Common tool for “jacking up” stuff.
 

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Tony,

If material strength is the basis for the concern about shearing a bolt on the horizontal stab attachment I don’t understand why one would worry. Maybe there is something I am missing.

Rich

Did I say I was worried? Just musing is all, everyone's opinions count. The size of the bolt is an indicator of robustnous of the attachment structure.
 
This is what I use. I use it to lift the entire airplane from the center or I put it under one wing tie-down and lift one main wheel up for service. To lift the nose wheel I added a short chain with a hook that I attach to the tail tie-down eye then lower the table, the weight of the lift pulls the tail down. The handle is easily modded to lay flat so it’s not in the way.

Harbor Freight $319

D5726633-5AE7-4FAF-B77F-08CD68F63079.jpeg
 
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This is what I use. I use it to lift the entire airplane from the center or I put it under one wing tie-down and lift one main wheel up for service. To lift the nose wheel I added a short chain with a hook that I attach to the tail tie-down eye then lower the table, the weight of the lift pulls the tail down. The handle is easily modded to lay flat so it’s not in the way.

Harbor Freight $319

View attachment 17234

I like it!

When not using it as a jack I can see various other uses for this device.
 
Tony,

Unless my math is wrong it takes 1000 pounds in shear just to get a 1/4” bolt to deform. It would take 5 times that to get it to fail. Seems pretty robust.

Rich
 
Tony,

Unless my math is wrong it takes 1000 pounds in shear just to get a 1/4” bolt to deform. It would take 5 times that to get it to fail. Seems pretty robust.

Rich
Your math is OK. And, the bolts are in double shear as well. I never meant to question your numbers, my 1st post in this thread was only to acknowledge that a PH.D engineer/professor would be familiar with shear strength. The stab is interesting, but this is probably not the thread to discuss it and I'm afraid we've run it off the tracks.
 
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Optimum saw horses

According to the RV-12/RV-12iS maintenance manual you should use a "25 inch tall stand" with 500 pound capacity under the appropriate rivet lines to get your RV-12 off the ground.

But where are you going to find a 25-inch-tall stand? I was at Home Depot one day and saw pre-made "Burro Brand" sawhorses. Label on the sawhorses said they are rated at 2000 pounds if you have two of them because, I suppose, no one ever buys just one sawhorse. They come in two heights 24" and 29". I bought two of the 29-inchers.

https://www.homedepot.com/p/Signature-Development-29-in-Wooden-Sawhorse-378739/100029549

When I got them home, I discovered the distance from floor to top of sawhorses was 28.5 inches. The legs don't go straight down, of course – they are 15 degrees off vertical. So how much to cut off to make top of the sawhorse 25" above the ground? I did some serious trigonometry (because I enjoy that sort of thing) and figured it out exactly...but it occurred to me that all I had to do was measure 3.5 inches off the floor and I put a dot on the outside of the leg (if you measure with a ruler laying against the leg you should put the dot at 3.633 inches...got that from my trig analysis).

I say put a dot vs. drawing a line because you want that line to be parallel with the ground. The way I accomplish that is by holding a small level against the leg right at the dot, center the bubble, and then draw the line. You want the bottom of the legs to be flat on the floor, of course. The legs are 15 degrees off vertical so set the angle on your skill saw to 15 degrees and cut on the line.

So I did all of that, laid a folded-over-several-times blanket on top of the sawhorses, did the drill to put saw horses under the appropriate places on the belly...and neither tire cleared the ground! So, I added a 2x6 to the top of the sawhorses (so now the height is 26.5 inches). That puts the tail lower after I put the sawhorse under the boarding steps, but I can still get under the tail for the lift to put the other sawhorse under the rear wing spar receptacles without any trouble. (I have two locations. For the second set I cut 2 inches vs. 3.5 off the legs using my technique above so I didn’t have to add the 2x6.)
 
Jacking an RV12

Wintermotorsports did develop a Jackpoint for the RV12 a couple of years ago but there was no demand so we discontinued it.
 
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