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  #11  
Old Yesterday, 10:52 PM
arffguy arffguy is offline
 
Join Date: Jan 2005
Location: Elk Grove, CA
Posts: 340
Default Loss of elevator control

Quote:
Originally Posted by Ironflight View Post
I don't know of any crashes caused by disconnected controls.
Actually, someone I knew did. He was a former Air Force B-47 Stratojet pilot. It was his favorite airplane.

https://www.ntsb.gov/news/press-rele...00LA155&akey=1
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  #12  
Old Today, 12:00 AM
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Ironflight Ironflight is offline
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Location: Dayton, NV
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Default

Quote:
Originally Posted by arffguy View Post
Actually, someone I knew did. He was a former Air Force B-47 Stratojet pilot. It was his favorite airplane.

https://www.ntsb.gov/news/press-rele...00LA155&akey=1
Fair enough - you're right! But....that was a jam nut that was loose and the rod end bearing backed out of the pushrods. Totally different cause than a unlock coming off. Control disconnect, just the same - but four a different reason than was being discussed here.

Good reminder to check those jam nuts!

Paul
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  #13  
Old Today, 07:10 AM
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daddyman daddyman is offline
 
Join Date: Jan 2014
Location: Fredericksburg, Virginia
Posts: 198
Default I was repairing a cracked elevator hinge

Quote:
Originally Posted by Michael Henning View Post
Daddyman,
How did you find out you lost the nut? After flying aerobatic aircraft, I put on a plexiglass inspection cover to be able to visually inspect before each flight.
I went into the space to remove the rod end as the elevator crack was discovered during annual inspection.

I believe the problem was that the original bolt was too short.
Why the builder put a critical bolt on that was too short is beyond me.

That caused the control ends to be pinched. There was not enough thread exposed to have the nut + 2 threads, just barely enough for the threads to catch.

I accept Paul Dye's comment, however, it was the original builder that began a deviation from plans. Mine was merely a fix that brought comfort to my mind.

Daddyman
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  #14  
Old Today, 08:12 AM
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az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 8,855
Exclamation Belts and braces

If you must deviate from the plans and insist on a cotter pin, then you should consider a MS17825 nut - a nylon insert locking castle nut -

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  #15  
Old Today, 11:00 AM
chris mitchell chris mitchell is offline
 
Join Date: Jul 2006
Location: near Harrogate, England
Posts: 327
Default

Paul, I completely agree with you about Vans design, and as you say there are many RVs of all flavours flying with nylocked control linkages. Now that Daddyman has told us that the original bolt was too short (and inadequately torqued??), I think Iíll stay with the plans ie nylon unless otherwise specified.

I suspect that some (many??) people do not realise how these rod end joints are supposed to work and do not know that the rotation is within the rod end, not around the bolt. Like others, I have seen control surfaces with inadequately tightened bolts, usually because the position of the rod ends was incorrectly adjusted and the only way to get fee movement was with a loose bolt.

As ever, I am impressed by how (relatively) impervious Cans designs are to builder errors - some of the mistakes I have seen have been horrendous, but there are few disasters.

Chris
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  #16  
Old Today, 12:02 PM
David Paule David Paule is online now
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,256
Default

Quote:
Originally Posted by az_gila View Post
If you must deviate from the plans and insist on a cotter pin, then you should consider a MS17825 nut - a nylon insert locking castle nut....
Darn right!

Dave
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