7A elevator spar crack

[RVG8tor]

I am coming up on my annual and to be honest I was not planning to put a wrench on these nuts. I set the torque when I installed them for the final time and marked them. With the discussions on this forum I have given them a close look.

What is the procedure you a talking about, do you loosen then reset the torque. I am no expert but two things come to mind, if the torque was set originally and marked and there has been no movement then all should be good. Second if you loosen then rest the torque then it seems to me you run the risk that you will make a mistake doing this then set yourself up for future issues. Kind of like a quote I heard once; "the Annual is where the mechanic takes your plane apart to see why it is still working normally". The implication is if it is working fine don't mess with it otherwise you might induce some sort of failure.

I would be curious to hear what the proper way to check these items. do you actually reset the torque on all the hardware throughout the aircraft?

This is the learning part of this hobby so I look forward to all opinions.

Cheers

[Walt]

Originally Posted by RVG8tor

I am coming up on my annual and to be honest I was not planning to put a wrench on these nuts. I set the torque when I installed them for the final time and marked them. With the discussions on this forum I have given them a close look.

What is the procedure you a talking about, do you loosen then reset the torque. I am no expert but two things come to mind, if the torque was set originally and marked and there has been no movement then all should be good. Second if you loosen then rest the torque then it seems to me you run the risk that you will make a mistake doing this then set yourself up for future issues. Kind of like a quote I heard once; "the Annual is where the mechanic takes your plane apart to see why it is still working normally". The implication is if it is working fine don't mess with it otherwise you might induce some sort of failure.

I would be curious to hear what the proper way to check these items. do you actually reset the torque on all the hardware throughout the aircraft?

This is the learning part of this hobby so I look forward to all opinions.

Cheers

from post #154

Quote:
Originally Posted by vic syracuse
That those locknuts on the rod end bearings, once tightened and torque- sealed, would never come lose without visibly breaking the torque seal. Yesterday, I found myself shaken to the core, seriously. I always visibly look at the locknuts on the all control surfaces during a preflight for just that, and I routinely touch most, but not all of them. Well, yesterday, after 720 hours on the Hobbs, I checked the tail a little more closely and I found one on the left elevator, and one on the rudder that I turned with my fingers during the preflight!
end Quote

My response:
This is precisely why I have said many times that a dab of torque seal means nothing to me when doing an inspection, its presence does not guarantee proper torque, only a wrench can do that.

Walt

[bruceg]

After finding 4 loose jam nuts on a friends RV-7 elevator, I noticed creaking noises when I wiggled the tip of the HS. There were also creaking sounds when I pushed down on the tail spring. So I put a wrench on every nut/bolt I could find in the tail area and took a closer look at everything. I found a total of 22 loose fasteners including 12 in the VS/HS attach area. Total time on this airplane is 350 and most of it is off an average grass field. Gotta really do the condition inspections

[cajunwings]

Just did a annual/condition insp on a 10 yr old 6A with 510 hrs total time. Most of the elevator and rudder rod end jam nuts needed to be tightened about 1 to 2 flats and most of nuts and bolts attaching the vertical fin and horiz stab to the fuselage needed tightening.


Don Broussard
A&P, IA
RV 9 Rebuild in Progress

[plehrke]

Originally Posted by cajunwings

Just did a annual/condition insp on a 10 yr old 6A with 510 hrs total time. Most of the elevator and rudder rod end jam nuts needed to be tightened about 1 to 2 flats and most of nuts and bolts attaching the vertical fin and horiz stab to the fuselage needed tightening.


Don Broussard
A&P, IA
RV 9 Rebuild in Progress

When you say they needed tightening do you mean they "could be turned 1-2 flats" or do you mean they "needed 1-2 turns to meet the required torque"?
Just cautioning on turn nuts just because you can and end up over torquing.

[wrongway john]

As a non-builder, not sure how anyone could get a torque wrench in such a place after the build. And how many ft-lbs are we talking if we could? I did cut a notch into a wrench like Walt, but sacrificed a Harbor Freight wrench instead. Just $15.00 for 8 wrenches with 16 different sizes. I also grinded down the head of it a bit to make it thinner to get in and out, otherwise you won't be able to get it over the shaft to get to the nut. Also had to grind down other parts of it as well. It?s still a snug fit, but does a much better job.

I checked all of the other nuts in the VS, and all showed to be quite snug. 565 TT hours on the airframe, but this 8 tail probably only has about 200 hours or so.

I think I?ll remove the main wing inspection plates next, and see what else can keep me up at night. I?ve got a CI coming up next month, I?ll spend more time on it than ever before, and will probably have more hours looking things over than the A&P himself. Maybe this will start giving me peace of mind again.

[ArVeeNiner]

Originally Posted by RVG8tor

I would be curious to hear what the proper way to check these items. do you actually reset the torque on all the hardware throughout the aircraft?

This is the learning part of this hobby so I look forward to all opinions.

Cheers

No, you don't reset the torque. What I do is put a wrench on the fastener that you want to check. Put some light to moderate force towards the tighten direction. You're not cranking hard here. If you get movement, that's when you want to re-torque the fastener.

I have used broken torque stripe as an indicator during pre-flights but as Vic pointed out, this is not fool proof. I have heard that the torque stripe can release on one surface but not the other and allow the fastener to move without showing a break in the stripe. I can't recall seeing that lately at work on our satellites or on my plane but I know it can happen.

At the CI, I'll put a wrench on those critical fasteners on the airplane that don't have a locking feature using the procedure above. This includes fuel lines, control surface jam nuts, and such. If we are talking about safetied hardware, such as those with safety wire or cotter pins, I don't generally remove the locking mechanism to check. The big exception is the prop bolts. I do remove the safety wire and check those.

I've only been through one CI on my plane and, although I didn't find many loose fasteners, the majority were firewall forward. The valve cover screws like to loosen up but I wouldn't call them critical.

That's my 2 cents.

[alpinelakespilot2000]

Originally Posted by wrongway john

As a non-builder, not sure how anyone could get a torque wrench in such a place after the build. And how many ft-lbs are we talking if we could?

A crows foot with a short extension works just fine to torque. And, we're talking in-lbs here, not ft-lbs!

[lucaperazzolli]

After doing some research I decided to perform a little mod into my flight control chain.

I'll change all the nuts/bolts with this combination :

- bolts : ANn-n instead of ANn-nA
- nuts : MS17825-n instead AN365-n
- and a cotter pin, of course

MS17825 is a castle lock nut (both world an365 + an310)

.

All the replacement cost in my 8 is circa 75 us dollars, in my opinion worth the money

[tc1234c]

I checked all my jam nuts on tail and all of them are good. This is after 1,370 hrs of service.

I also checked a friend's newly acquired low time RV. I found all the jam nuts on elevator and rudder were loose.

I did not use a torque wrench on mine. But from the outcome I can conclude that they are tight enough. Just offer one data point. Those jam nuts don't always come loose after certain hours in service.

Of course I will continue to check all nuts and screws.