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RV-12 Tie Down

JoeM said:
Would it be acceptable to use the wingtip handles to tie down?
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Hi Joe,

The wing tie-downs are very strongly attached to the front spar to take the load, the wing tip handles were designed to allow you to hold about 50 pounds (the maximum weight you will see at that end of the wing) when handling the wing, they work just fine as hand holds but would not take the load of the aircraft trying to fly while tied down. It is a very simple thing to screw in the tie-down rings when you tie it down.

Best regards,
Vern
 
There is also a loop welded to the lower portion of the nose gear leg that can also be used for tie down purposes. The presence of a nose wheel pant makes such use somewhat problematic, but you could still "triangulate" some kind of tie down rope/spike arranagement if the winds were forecast to really howl. David
 
Tie Down

What drawing shows the tie down?
We did not build the wings. We do not have a hole where the tie dowen should be attached
 
If you look at the top of the wings, you will find a small hole just opposite of where the tie downs go on the bottom of the wings. If you ever need a crane to lift your 12 straight up (for loading on a barge for example), you can drill out these holes in the top of the wings, insert 3/8" eye-bolts and attach a lifting cradle to the eye-bolts. Learned this little tidbit on a recent visit to the factory. They are always thinking ahead.
 
Unless you are going EAB. For the ELSA people, you are supposed to drill out the top wing "tiedowns" as well as the bottom. I am looking for some sort of machine gun or rocket fixtures to fill the holes with.

ChuckC said:
If you look at the top of the wings, you will find a small hole just opposite of where the tie downs go on the bottom of the wings. If you ever need a crane to lift your 12 straight up (for loading on a barge for example), you can drill out these holes in the top of the wings, insert 3/8" eye-bolts and attach a lifting cradle to the eye-bolts. Learned this little tidbit on a recent visit to the factory. They are always thinking ahead.
Click to expand...
 
Alschief said:
What drawing shows the tie down?
We did not build the wings. We do not have a hole where the tie dowen should be attached
Click to expand...

There is the (maybe remote) possiblilty that the builder did not tap the holes for the tie downs. Why would they not open the access holes?
 
On the factory red plane, they have drilled out the tie down access hole on the bottom of the wing. But, on the top of the wing, the access hole has not been drilled out.
 
The plans do not specify that you have to drill out the top holes
and my skins have no pilot hole on the top,.
I only final drilled the bottom holes, but I did tap the AEX on both sides, just in case.
 
Tony_T said:
There is the (maybe remote) possiblilty that the builder did not tap the holes for the tie downs. Why would they not open the access holes?
Click to expand...

hi have a look for a hole without a rivet in it or they may have placed a rivet in the hole to fill it up look for a rivet that doesnt line up with the others
you can then drill the rivets out and if need be tap the tie down brackets then
 
Rv-12 Tie Down

Thanks for the input. We did not receive the drawings for the wings.
We will try and locate the points and tap them today
 
tim walter said:
The plans do not specify that you have to drill out the top holes
and my skins have no pilot hole on the top,.
Click to expand...

All of the skins have the pilot hole at the top location. Maybe when your wings were assembled, someone installed a rivet in that hole location? (The pilot holes are the same size as all of the other rivet holes)
 
Upper "Tie-Down" port for aircraft lift

As hangar space availability is a real issue over here, I am planning ahead for having the option to lift my bird up to the ceiling.
If I have understood correctly, the upper 3/8 threads of the tie-down parts on the wing-spars are meant for that purpose and I assume they are strong enough for an empty RV-12 with full fuel on board at max.

Now I am wondering if anybody has already lift his bird on these ports and which third hard point was used on the plane. I am not yet that far in the building process, but I guess I would add something similar somewhere on the firewall or using the engine mount for that. Would that makes sense?

Any inputs or experience in lifting your RV-12 are greatly appreciated.
Thank you !!
 
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Tie down fitting

The original wing skins had a #30 hole and you opened it up to a 1/2"with a step reamer. If the fitting is not threaded , which it should be, you can tap it, I think it's 3/8 tap. This should be an easy job to do.
 
As a point of reference, my nosewheel had 133 pounds on it with 304 (L) and 313(R) on the mains. Total 750 empty no fuel. I was thinking you could consider a sling behind the prop, but that's likely not a great idea. Using the motor mount would require taking off the top cowl and covering with towels or something. I haven't read here of anyone actually using those suspension points. I tapped my top ones but then put rivets in the holes.
 
3/8" hole on top of wing

I (unfortunately) drilled out the 3/8" hole on the top of the wing for the tie up and was wondering what others have done to cover it up (so water... does not get in the wing) while not (if ever) in use?
 
Not a big deal. My Cherokee has a plug on each wing to gain access to the landing gear strut charging valve. Each has a small cap that pops out to get to the Schrader valve.

Since you have the hole you may as well tap it in case you want to use it as a lifting point later.
 
You can use the HW-00003 plastic caps used at the 3/8 holes near the gear:

Schermafbeelding%25202015-03-31%2520om%252010.26.56.png
 
Gagarin737 said:
You can use the HW-00003 plastic caps used at the 3/8 holes near the gear:

Schermafbeelding%25202015-03-31%2520om%252010.26.56.png
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Very crafty, Joery! I had the same thought but gave-up explaining what it was and where it was. Your picture saved the day!
Who said "a good picture is better than a long speech"?
 
The KAI says jacking the plane at the wing tiedowns is OK. If you can jack it you can lift it. It's the same applied loads and the same supporting structure. It would make me feel uncomfortable to see it lifted this way---I guess I need to see safety nets. But I taught structural design for many years and the textbook answer is that it should work.
 
Charlie, you're logic seems sound, but if the threads pull out lifting the plane any substantial distance the consequences seem worse than if the threads collapse under compression from jacking because the threaded Jack rod will bottom out against the portion of the tie down block that has not been final drilled for tapping.

Rich
 
I agree. That's the kind of safety net that I would prefer to see.

But on a 3/8 bolt the area that would have to fail in shear to pull out the threads is pretty big. A few hundred pounds tension on whatever fastener is threaded in should not be any real threat even with aluminum threads.

Last year I asked someone at Van's about why I was instructed to bother tapping the top of the fitting. The answer was that there was once a concept floating around to use the top of the fitting as a lift ring to create a device to assist with solo installation of the wings. The idea faded away but I kind of like it.
 
Charlie,

I agree it's unlikely the threads would pull out, but that's little consolation if it happens. I once attended a lecture on risk. It was defined as probability times consequences. Extremely low probability times unacceptable consequences produces high risk! 😱

Rich
 
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