Matronics Email Lists :: View topic - 701 seat belt attach-Zenith fix

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

701 seat belt attach-Zenith fix

Matronics Email Lists Forum Index -> Zenith-List

View previous topic :: View next topic

Author Message

John Bolding

Joined: 23 May 2006
Posts: 281

Posted: Sun Oct 01, 2006 6:36 am Post subject: 701 seat belt attach-Zenith fix

Lo and behold,Zenith just announced a "fix" for  the failed fitting on the seat belt attach on the 701. 

 I guess I'm just hard to please but I really don't  understand the "fix".  

 The problem lies in the fact that the pop rivets  pulled out of the seat tunnel cleanly, they did NOT tear large holes where they  were installed.

 The fix is just a simple doubler on the inside of  the seat tunnel.  I CANNOT get my arms around how that fixes the problem.  If the problem was tearing out a chunk of tunnel with the fitting still  attached, then a doubler to spread out the load over a wider area(or thicker  tunnel) is a proper fix, BUT if the problem is pulled rivets then why would  not the rivets pull just a cleanly thru the doubler as well.?? Couple of bolts  MIGHT be the solution.

 I was doubtful that Zenith would respond to  this situation so I farmed out a fix for MY airplane which ended up going down  to the gear tunnel with a 2 piece fitting rived to the tunnel on 2 sides with  proper driven rivets.  The engineer that did it for me said our friendship  is over if I post a drawing as he has NO control over the rest of the structure  but he said it was capable of multiples of the load of the original.  He  questioned why that the wing spar and fuselage sides had driven rivets and this  fitting which is loaded higher has pops.??   I had no answer for  him.

  

 LOW&SLOW   John  Bolding

    [quote][b]

- The Matronics Zenith-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Zenith-List

cffd(at)pgrb.com
Guest

Posted: Sun Oct 01, 2006 7:49 am Post subject: 701 seat belt attach-Zenith fix

John,

  

 Here is a comment I made previously.

  

 When I built my 701, I did not feel comfortable with the aluminum seat  belt

attachment that was riveted to the tunnel.  In fact, somewhere 4 or  5 years

ago, on this forum, I read where the bolt between the seat belt and  the

aluminum attachment pulled a slot through the attachment.  So I made  my

attachment from 0.40" 4130 steel instead of 0.40" 6061 aluminum.  I  then

used the 0.40" 6061 as a doubler on the inside of the tunnel to give  more

thickness to keep the rivets from pulling through. I did not ask ZAC  about

this, but I feel that this is a stronger anchor which actually gets  pulled

by both the lap and shoulder straps.



Chuck  D.

N701TX



 [quote]   ---

- The Matronics Zenith-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Zenith-List

craig(at)craigandjean.com
Guest

Posted: Sun Oct 01, 2006 8:06 am Post subject: 701 seat belt attach-Zenith fix

Did you ask Zenith for their reasoning?

  

 -- Craig



   From: owner-zenith-list-server(at)matronics.com  [mailto:owner-zenith-list-server(at)matronics.com] On Behalf Of John  Bolding

Sent: Sunday, October 01, 2006 8:34 AM

To:  zenith-list(at)matronics.com

Subject: 701 seat belt  attach-Zenith fix

 

 Lo and behold,Zenith just announced a "fix" for  the failed fitting on the seat belt attach on the 701. 

 I guess I'm just hard to please but I really don't  understand the "fix".  

 The problem lies in the fact that the pop rivets  pulled out of the seat tunnel cleanly, they did NOT tear large holes where they  were installed.

 The fix is just a simple doubler on the inside of  the seat tunnel.  I CANNOT get my arms around how that fixes the problem.  If the problem was tearing out a chunk of tunnel with the fitting still  attached, then a doubler to spread out the load over a wider area(or thicker  tunnel) is a proper fix, BUT if the problem is pulled rivets then why would  not the rivets pull just a cleanly thru the doubler as well.?? Couple of bolts  MIGHT be the solution.

 I was doubtful that Zenith would respond to  this situation so I farmed out a fix for MY airplane which ended up going down  to the gear tunnel with a 2 piece fitting rived to the tunnel on 2 sides with  proper driven rivets.  The engineer that did it for me said our friendship  is over if I post a drawing as he has NO control over the rest of the structure  but he said it was capable of multiples of the load of the original.  He  questioned why that the wing spar and fuselage sides had driven rivets and this  fitting which is loaded higher has pops.??   I had no answer for  him.

  

 LOW&SLOW   John Bolding

[quote]

[b]

- The Matronics Zenith-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Zenith-List

jetboy

Joined: 22 Jul 2006
Posts: 233

Posted: Sun Oct 01, 2006 4:45 pm Post subject: Re: 701 seat belt attach-Zenith fix

I studied the revised ZAC drawing to see how it may apply to my CZAW built airframe as that has a drawing 7-F-16B dated 12/2002 showing the attach fitting (3) with 7 rivets A5 (4 along upper edge and 3 spaced between them and along lower edge)



This is noted as a change for BCAR 'S' compliance requirements

- The Matronics Zenith-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Zenith-List

_________________
Ralph - CH701 / 2200a

Display posts from previous:

	Matronics Email Lists Forum Index -> Zenith-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum