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Bellcrank bolt loose for stabilator control rod


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When rod ends are involved, especially with soft plastic inserts, the torque spec is "snug" unless otherwise specified. It's so you don't bulge the bearing in the rod and prevent rotation. So point 1 is moot, and point two doesn't matter since the locktite that I applied is much stronger than the fiber.

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Great video - including the sound effects.  Thanks for superimposing the translation.  "A picture video tells a thousand words"!  The information I've seen in this thread leaves no doubt that I will check for fastener integrity on my CT (immediately and periodically).

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Have a look at this video done by my mechanic: CTSW 2007 / 1000 hours. I never done the test before, and never though I needed to check the rear bolt... Now I do!

Did you feel the stabilator being loose in flight?

 

Are the dams on your stabilator standard in Europe? I'm not familiar with them.

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exactly the same problem as mine..  that was at landing that I noticed it.

(pulling on the stick..the cable (teleflex) was moving forward)

 

merci Marco01 for the video

 

Jim, I have seen the 'dam' only on European model  ..Marc will tell if they are standard

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When rod ends are involved, especially with soft plastic inserts, the torque spec is "snug" unless otherwise specified. It's so you don't bulge the bearing in the rod and prevent rotation. So point 1 is moot, and point two doesn't matter since the locktite that I applied is much stronger than the fiber.

 

Corey, I don't think I have seen any rod ends with soft plastic inserts on a CT. I also don't find any notes about torque for rod ends, other than the standard torque for the size bolt being used. In my experience rod ends with a steel ball get standard torque for the size bolt being used. The whole purpose for using a rod end is so the bolt can be tightened down, allowing rotation without wearing out the holes or fastener.

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Did you feel the stabilator being loose in flight?Are the dams on your stabilator standard in Europe? I'm not familiar with them.

i have felt one time strange vibration while,going done with high speed in turbulence... Few days weeks after, FD published a CN that VNE was set to 225Km/h max until stab modification is down (compensating stab needed to be shorten + vertical dam to be added).
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i have felt one time strange vibration while,going done with high speed in turbulence... Few days weeks after, FD published a CN that VNE was set to 225Km/h max until stab modification is down (compensating stab needed to be shorten + vertical dam to be added).

this CN only apply to CTSW made for Europe.
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Andy, interesting to see the short anti-servo and Marco's comments.

 

I have ordered ball ends from FD in both the 5mm and 6mm size.  My experience with these joints both from the factory and replacements shows all have steel throughout the joints.  I have not seen any plastic.

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Corey, I don't think I have seen any rod ends with soft plastic inserts on a CT. I also don't find any notes about torque for rod ends, other than the standard torque for the size bolt being used. In my experience rod ends with a steel ball get standard torque for the size bolt being used. The whole purpose for using a rod end is so the bolt can be tightened down, allowing rotation without wearing out the holes or fastener.

 

The aileron and flaps in the hinges use plastic bearings on our planes, I meant to also include those in that statement. I'll doublecheck, but I'm pretty sure that rod was plastic too (was dark outside and I only had a flashlight trying to look down in there). I don't remember seeing a bearing surface on the bellcrank either, and I didn't want to torque it down and possibly lock up the flight controls if the rod end seized.

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Marco01,

 

would you have the link (info) on your trim tab mod

 

I have found this 

http://www.daec.de/fileadmin/user_upload/files/2012/luftsportgeraete_buero/LTA/61151/Anlage_LSG_12_003.pdf

 

but it looks like 3 years ago...is it the right one....

 

just curious   I alreay have the short trim tab on my 2005

Yes that's the right one: I was late to get the modification done, but OK until I don't go over 225km/h. If you have already the short trim tab, nothing to be done...

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The aileron and flaps in the hinges use plastic bearings on our planes, I meant to also include those in that statement. I'll doublecheck, but I'm pretty sure that rod was plastic too (was dark outside and I only had a flashlight trying to look down in there). I don't remember seeing a bearing surface on the bellcrank either, and I didn't want to torque it down and possibly lock up the flight controls if the rod end seized.

 

Like I said before I don't think I have ever seen a plastic rod end on a CT. The bellcrank doesn't have a bearing, nor does it need one. That is what the bearing in the rod end is for. By design the rod end should be tight against the bellcrank. Personally I would be concerned with it being loose rather than to tight. The way the design is if it is loose you will be working the bolt and creating a possible catastrophic failure point. At least that is the way I see it based on 35 years working on airplanes.

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Have a look at this video done by my mechanic: CTSW 2007 / 1000 hours. I never done the test before, and never though I needed to check the rear bolt... Now I do!

 

Make sure you report your findings to your distributor. It's definitely something FD should look at.

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Like I said before I don't think I have ever seen a plastic rod end on a CT. The bellcrank doesn't have a bearing, nor does it need one. That is what the bearing in the rod end is for. By design the rod end should be tight against the bellcrank. Personally I would be concerned with it being loose rather than to tight. The way the design is if it is loose you will be working the bolt and creating a possible catastrophic failure point. At least that is the way I see it based on 35 years working on airplanes.

 

I wouldn't say it's loose. I've tightened it to "snug", which means there isn't any play, but I'm not binding anything either. I'm waiting for a response from Arian about the torque spec of that bolt anyways.

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Andy.  Both the 6mm nut which fastens the rod end to the bell crank and the large nut which connects the teleflex cable to the aluminum bracket are shown to have loosened up in the thread.  Jacques photos have arrows pointing to both of the fasteners and Marcos video  shows the loose nut on the teleflex.

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I would like to try to sum up what has been reported for my own benefit.  The lock nut which fastens the 6mm bolt used to connect the rod end and also the large nut which connects the teleflex cable to the stationary aluminum bracket are being reported to have have loosened up.  Corey started the thread by reporting he found the nut had backed off the 6mm bolt which fastens the rod end in the front tunnel area.  Both Jacques and Marcos report that the nut which secures the teleflex cable to the aluminum bracket had backed off resulting in a loose cable.  Jacques photos has arrows pointing to both the 10mm nut and also the large nut which fastens the teleflex.  Marcos video shows the loose nut on the teleflex cable and the play in the cable resulting from this looseness.  Although it's not loose, this video also shows the rod end used to connect the teleflex to the stab bracket in the foreground.  The same 6mm bolt and nut used to connect the rod end and the teleflex fastening nut are used at the other end of the cable in the tunnel area.  Someone please correct me if wrong. 

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Hi Dick

 

you got it right.. 2 differents ''issue'' here   both related to the  elevator cable system.

 

but the problem is the same..=  nuts  that came loose ...because they had NO system to prevent this

 

the 2 M6 nuts at each end should be castle nuts with cutter pins  (standard practice)

the big nut  on the teleflex  could have been ''safety wired '' to prevent loosing

 

 

just my 2 cents

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Hi Dick

 

you got it right.. 2 differents ''issue'' here   both related to the  elevator cable system.

 

but the problem is the same..=  nuts  that came loose ...because they had NO system to prevent this

 

the 2 M6 nuts at each end should be castle nuts with cutter pins  (standard practice)

the big nut  on the teleflex  could have been ''safety wired '' to prevent loosing

 

 

just my 2 cents

I will have to lok at a parts catalog for a couple other airplanes, but I think a lock nut is pretty standard in this application.

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