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  #31  
Old 01-03-2013, 03:11 PM
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DanH DanH is offline
 
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Quote:
Originally Posted by N427EF View Post
Safety wire is installed to keep the pushrod from rotating
For whatever reason on the RV10 only.
It has no bearing on the safety of the nut and bolt.
Apparently because of the long shank on the GMM-4M-675 rod end. If both jam nuts got loose the pushrod could rotate onto the long shank and run off the short shank on the other end.

http://www.myrv10.com/Plans/RV10_Plans_sec39-pg03.html
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  #32  
Old 01-03-2013, 03:24 PM
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Is there any way the safety wire could be mis-installed, or move/slip, and alter the working of the joint such that the bolt did turn / rachet one way, and "wind off" the nut?

There's something about that drawing and the safety wire that just doesn't look ideal to me, when combined with the theory of a nyloc being safe due no possible rotation of the bolt...
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  #33  
Old 01-03-2013, 03:33 PM
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Quote:
Originally Posted by N427EF View Post
Safety wire is installed to keep the pushrod from rotating
For whatever reason on the RV10 only.
It has no bearing on the safety of the nut and bolt.
Thanks, Ernst...I do believe there was an accident in the past few years where the end bearing pulled out of the pushrod. It was on an -8 doing acro, and the pilot had time to transmit that he lost elevator control.

My question was about the possibility of adding safety wire to the rod-ends so if they did detach, for whatever reason, that you would still have safety wire making the (albeit, loose) connection. That may still give you some control, I would think.

Is my thinking out of line on the need for this? I know it doesn't happen often, but I would think the loads pulling on the eye bolt would be pretty strong in many cases (high speed, large deflection, for example).
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  #34  
Old 01-03-2013, 03:35 PM
ReidVaitor ReidVaitor is offline
 
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Default RV-10 accident

Sonny- the safety wire is not around the bolt, it is secured under the bolt to assure the pushrod does not twist from it's installed length.
There are over 400 flying RV-10s, no has ever had this problem with the properly torqued bolt.

Pascal
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  #35  
Old 01-03-2013, 04:12 PM
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Do we know where (what altitude) the failure occurred? Was the aircraft flown for a period of time with trim only? Inquiring minds want to know.
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  #36  
Old 01-03-2013, 04:18 PM
vic syracuse vic syracuse is offline
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Yes, I have seen this nut loose on a few inspections, including two very recent ones in the last month. I find it amazing that the final inspection ALL builders should perform is to go over the entire control system from beginning to end in all axis, insure each lock nut is tight, the jam nuts are tights, and the castle nuts have cotter pins in them and then MARK them with torque seal. It gives peace of mind to everyone. Once I find a loose jamnut or locknut on the airplanes I inspect, and there is no visible torque seal, I no longer trust the rest of the airplane.
It also pays many dividends for future inspections. One quick glance can confirm the security of the device.

Vic
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  #37  
Old 01-03-2013, 05:43 PM
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Ron Lee Ron Lee is offline
 
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When I did the first flight for a 7A that I did not build, I took the time to examine every flight critical connection end to end. I looked to ensure that bolts and nuts were on, rivets installed to hold those VA-111 thingies, critical engine controls and hoses were on and secured, etc.

It took a while but it was my life on the line.
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  #38  
Old 01-03-2013, 06:27 PM
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IowaRV9Dreamer IowaRV9Dreamer is offline
 
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Default what safety wire on jam nuts?

Quote:
Originally Posted by Mike S View Post
True, but if you look at the drawings, there is a jam nut, and it is safety wired.
Hi Mike - I looked at my plans (-9A) and there is no safety wire on any of the jam nuts on any of the 7 pushrods that I can see. Also can't find it in the builders manual. Is it a -10 thing, did Vans add it after my kit, or did I just miss it and will someday have an interesting inspection?
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  #39  
Old 01-03-2013, 06:33 PM
vic syracuse vic syracuse is offline
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Default only on the 10

I'm pretty certain only the 10 has the forward rod end saftied, as it is much longer than any of the others due to clearance in that area.

Vic
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  #40  
Old 01-03-2013, 07:13 PM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by vic syracuse View Post
I'm pretty certain only the 10 has the forward rod end saftied, as it is much longer than any of the others due to clearance in that area.

Vic
Vic is correct.

Keep in mind, these are all different airplanes.
Even though they are all called RV's, it doesn't mean everything about them is the same. (in fact when comparing an RV-9 and RV-10 flight control systems, there is probably more things different than there is the same)
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