Janekom

Janekom

Well Known Member
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I found this on a second hand RV6A. To me it is not acceptable and I thought the fix should be a new hole where I have placed the whit dot. I will appreciate advise on this. Then I guess it is also safe to say that one should be very careful when buying a plane someone else built.

RV6A_Elevator_Horn.jpg
 
Although ugly, the extra holes in the horn are not likely be a problem, relocating the hole up (2D away from current hole) would be a good fix but would also change the arm/throw on the elevator and could present another problem (stop to stop stick throw). Another option would be to weld a doubler on each side of the horn or just weld the exrtra holes shut.

Also you need to double check the thread engagement of the rod end into the torque tube, it looks like excessive threads showing to me.

Looking at the pic also reveals a number of rivets that have less than nominal ED.
 
not good

I agree with Walt (it does happen Walt). Remove the elevators, weld up the holes, relocate the new hole per the plans. Make sure you have the correct throw and thread engagement. In your picture look up above the jam nut at the top of the picture, to rivets side by side. What I see in the picture would have me taking the entire airplane back apart and checking every major area. I would not fly this airplane until that had been completed.

Pat
 
Pat Stewart said:
I agree with Walt (it does happen Walt). Remove the elevators, weld up the holes, relocate the new hole per the plans. Make sure you have the correct throw and thread engagement. In your picture look up above the jam nut at the top of the picture, to rivets side by side. What I see in the picture would have me taking the entire airplane back apart and checking every major area. I would not fly this airplane until that had been completed.

Pat
Click to expand...

Ditto,
I see three places with rivets on top of one another and a screw that is threaded into the radius of a longeron. This is all in a pretty small area. The repair to the elevator horns is easy enough but I would guess the rest of the airplane needs a thurough inspection.
Ryan
 
Also, are those "butter soft" aluminum hardware store pop rivets securing the end fitting to the pushrod?
 
Pat Stewart said:
... taking the entire airplane back apart and checking every major area. I would not fly this airplane until that had been completed.
Pat
Click to expand...
With a careful look at the stab and wing attach areas....

Toobuilder said:
Also, are those "butter soft" aluminum hardware store pop rivets securing the end fitting to the pushrod?
Click to expand...
How can you tell they are not MSP-42 that are specified?
10135_c.jpg

BTW: We built new ones...
 
Thanks guys.
Walt wrote:
but would also change the arm/throw on the elevator and could present another problem (stop to stop stick throw).
Click to expand...
The elevator will become slightly more sensitive as in the same movement on the stick will move the elevator slightly more.

The screw into the longeron is a #6 fixing the emp fairing. The rivets too close to each other will be difficult to fix.

The AC has been inspected very carefully and this was the only "structural" problem found that I did not like. There is one other problem - there is a soft alu fuel line in the engine bay without any fire sleeve that gives me the shivers.
 
elevator horn

If the bolt is AN3, if you have 1.5x the bolt diameter from the CENTER of the bolt hole to the closest edge of the
"extra" holes, I would leave it alone. This works out to .280 for a AN3 bolt, .375 for AN4 bolt. These are standard edge distances except for special circumstances. I do not favor welding holes closed. Welding doublers on the horns would be the next best option. DO NOT weld in a straight line across a doubler except on the outer edge. On the inner edge a couple of tack welds would be sufficient.
 
jrs14855 said:
If the bolt is AN3, if you have 1.5x the bolt diameter from the CENTER of the bolt hole to the closest edge of the
"extra" holes, I would leave it alone. This works out to .280 for a AN3 bolt, .375 for AN4 bolt. These are standard edge distances except for special circumstances. I do not favor welding holes closed. Welding doublers on the horns would be the next best option. DO NOT weld in a straight line across a doubler except on the outer edge. On the inner edge a couple of tack welds would be sufficient.
Click to expand...

I agree with Jim, IF you can confirm adequate thread engagement on the rod end.

The design is such that if the jamb nuts came loose on both ends of the rod end, and the push-pull tube rotated, it would bottom out on one rod end before it fully unthreaded off of the other.

At this point I would be much more concerned about strength of the minimal rod end engagement than I would about the strength of the elevator horns.
 
Don't be fightened by the fear mongers

The screw threaded through the longeron is exactly how Van's call for the fairings to be installed. Don't worry about it.

Likewise on 6's and others that did not have the luxury of prepunched fuselages, it was necessary to attach the bulkheads to the longerons in the fixture with a rivet, there is no other way to do it. Ideally you try to do it offset from were the row of rivets will go that will attach the skins. When you do attach the skins the rivet at the intersection of the longeron and bulkhead will be close to the first rivet. Leave it along, it is fine. If you have any doubts consult Van's.

If the construction of the airplane is of reasonable quality you will have to have some faith that the correct materials, like the push rod rivets, were used. If you do not you should build your own plane, as that is the only way to insure 100% that the correct material was used. In skydiving I have seen jumpers that have "gear fear", no matter how carefully the gear is taken care of, inspected and packed, they don't trust it. If you can't make the leap to trust your gear (airplane) after reasonable due care, you better take up bowling.

PS: I would be concerned about the soft aluminum fuel line in the engine compartment. The aluminum fuel line should not be used in the engine compartment even if it has a fire sleeve. How is it used?
 
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I agree with Frank

I agree with Frank.

The "off-center" rivets are how some things are held together until final riveting of the Non-Pre-Punched skins. Holes are laid out around the temporary rivets placement.

I do agree that the rod end needs to be checked. It looks a little long.

Maybe someone can post the exact dimension of an uninstalled rod end bearing threaded shaft length so the you can at least measure to insure you have 1/2 thread engagement.
 
Don't be fightened by the fear mongers

Well I guess I will take that personally, its not about fear its your safety. The poor quality displayed in that one small area to me suggest that you will find similar quality in other areas but I hope not, please look. If you call Vans I believe they will tell you to weld up the holes or replace the horns. Ive seen this one before. Please call Vans. I am an A&P with over 30 years experience in aircraft maintenance for what's it's worth. Your airplane and your decision.

Pat
 
Frank wrote:
PS: I would be concerned about the soft aluminum fuel line in the engine compartment. The aluminum fuel line should not be used in the engine compartment even if it has a fire sleeve. How is it used?
Click to expand...
Frank the soft alu fuel line enters the firewall through a bulkhead, then go to a gascolator (about 10 inches long) , then a fuel flow sender (another 10 inches or so). Then only does it change to a flexible fire sleeved fuel line as I am used to see and use.

I have given my advise of how to change this to the owner and they are fully aware of it and will change it. So now worries about that -I have just mentioned it as part of the conversation.

Overall it is well built and a nice example of an RV6A adn it was this guys second 6A. I have seen a lot and know them inside out. I hope :)
 
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