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Check your wing to fuselage fittings for tightness!

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mppalmer(at)aol.com
Guest

Posted: Mon Jun 04, 2012 1:36 pm Post subject: Check your wing to fuselage fittings for tightness!

We just completed our 16th "annual" inspection. (17th year of flying, 

3300 hrs.) I had rechecked the torque on the front and rear wing to 

fuselage fittings about seven to ten years ago, but to my surprise, the 

front screws took another quarter turn this time. The rear bolts were 

still pretty tight but needed an eighth of a turn.



I'm thinking that installing Countersunk Tinnerman washers on the front 

screws (which the factory called for in a SB and then later rescinded) 

might be a good idea. I'm guessing the screw heads are crushing the 

glass over time and, as with a wood prop and crushing fibers, need 

constant re-torquing?



(We also checked the engine mount to firewall torque years ago. Those 

bolts also needed a quarter turn more back then.)



FWIW, we fly straight & level. No aerobatics.



P.S. The plane is still for sale. glasairforsale,freevar.com



Hope this helps,



Mike Palmer <><

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n355tc(at)comcast.net
Guest

Posted: Mon Jun 04, 2012 2:40 pm Post subject: Check your wing to fuselage fittings for tightness!

With 3300 hours tightening them once doesn't sound too bad. Ironically, I just drilled these very holes to mount the wing on my glasair 3 today! 

Did you mark the nuts when you installed them to have a reference? This way you can tell if they are backing off or if indeed they are working into the fiberglass. Would be useful to know this one. Either way, 17 years and 3300 hours seems like quite a bit of flying to only need that small tweak.  Good luck with the sale, too bad you are leaving the ranks of glasairs.

Todd



Sent from my iPad



On Jun 4, 2012, at 5:06 PM, mppalmer(at)aol.com wrote:



 	  Quote: 	
		   

 

 We just completed our 16th "annual" inspection. (17th year of flying, 3300 hrs.) I had rechecked the torque on the front and rear wing to fuselage fittings about seven to ten years ago, but to my surprise, the front screws took another quarter turn this time. The rear bolts were still pretty tight but needed an eighth of a turn.

 

 I'm thinking that installing Countersunk Tinnerman washers on the front screws (which the factory called for in a SB and then later rescinded) might be a good idea. I'm guessing the screw heads are crushing the glass over time and, as with a wood prop and crushing fibers, need constant re-torquing?

 

 (We also checked the engine mount to firewall torque years ago. Those bolts also needed a quarter turn more back then.)

 

 FWIW, we fly straight & level. No aerobatics.

 

 P.S. The plane is still for sale. glasairforsale,freevar.com

 

 Hope this helps,

 

 Mike Palmer <><

- The Matronics Glasair-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:

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gossend(at)gmail.com
Guest

Posted: Mon Jun 04, 2012 4:18 pm Post subject: Check your wing to fuselage fittings for tightness!

Thanks, Mike. I'll check 'em. 

Dick Gossen

N90GG

22 years flying/1900 hours

On Jun 4, 2012, at 4:06 PM, mppalmer(at)aol.com wrote:



 	  Quote: 	
		   

 

 We just completed our 16th "annual" inspection. (17th year of flying, 3300 hrs.) I had rechecked the torque on the front and rear wing to fuselage fittings about seven to ten years ago, but to my surprise, the front screws took another quarter turn this time. The rear bolts were still pretty tight but needed an eighth of a turn.

 

 I'm thinking that installing Countersunk Tinnerman washers on the front screws (which the factory called for in a SB and then later rescinded) might be a good idea. I'm guessing the screw heads are crushing the glass over time and, as with a wood prop and crushing fibers, need constant re-torquing?

 

 (We also checked the engine mount to firewall torque years ago. Those bolts also needed a quarter turn more back then.)

 

 FWIW, we fly straight & level. No aerobatics.

 

 P.S. The plane is still for sale. glasairforsale,freevar.com

 

 Hope this helps,

 

 Mike Palmer <><

- The Matronics Glasair-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?Glasair-List

Craymondw(at)aol.com
Guest

Posted: Mon Jun 04, 2012 6:04 pm Post subject: Check your wing to fuselage fittings for tightness!

I talked to friend from Germany that built fiber glass yachts  beginning in the late 1950's through the late 1970's. Now he  produces fiber glass parts for aircraft ranging from wheel pants to wing  tips.   I remember him telling me that resin continues to cure  even after it's initial cure until it eventually disintegrates. Don't worry  because that will take a few hundred years or more. He reported the resin cures  in a curve that slowly drops off over time. I would imagine that as  the resin cures over lets say the first several years that it may also shrink.  Has anyone made any studies or taken any measurements? And could this  be the reason for screws and bolts becoming loose? Back in 1996 I had my nose  wheel assembly part company on my 1991 Glasair 2S Ft when we landed on  grass growing on a sandy type of soil and it flung into my right main  causing the wing to drop on the dangling right main strut causing the outer  bottom skin to dent a little. Those original 3/16 bolts holding on the nose  wheel  trunions stretched until they snapped causing the nose wheel  assembly to part company. When I had the wing in the shop and began to sand it  to scarf in layers of cloth I found I couldn't make any progress sanding it by  hand. So I used a body grinder beginning with 150 grit paper and nothing  happened, I kept switching paper until I ended using 80 steel grit!! I  found grinding through the factory layers harder than grinding through aircraft  sheet aluminum. My German friend asked me if I had built a tank!! 

         Here is a hint. In case you have  to make a fiber glass repair, after you use the heavy cloth and it has  cured use a very light fiber glass cloth used on model aircraft as a  finishing layer to cover up the weave of the heavier factory glass cloth weave.  After that spray it with a two part feather fill and block sand it out.   

  

  In a message dated 6/4/2012 5:37:03 P.M. Eastern Daylight Time,  mppalmer(at)aol.com writes:

  	  Quote: 	
		  -->    Glasair-List message posted by: mppalmer(at)aol.com



We just completed our    16th "annual" inspection. (17th year of flying, 

3300 hrs.) I had rechecked    the torque on the front and rear wing to 

fuselage fittings about seven to    ten years ago, but to my surprise, the 

front screws took another quarter    turn this time. The rear bolts were 

still pretty tight but needed an    eighth of a turn.



I'm thinking that installing Countersunk Tinnerman    washers on the front 

screws (which the factory called for in a SB and then    later rescinded) 

might be a good idea. I'm guessing the screw heads are    crushing the 

glass over time and, as with a wood prop and crushing fibers,    need 

constant re-torquing?



(We also checked the engine mount to    firewall torque years ago. Those 

bolts also needed a quarter turn more    back then.)



FWIW, we fly straight & level. No    aerobatics.



P.S. The plane is still for sale.    glasairforsale,freevar.com



Hope this helps,



Mike Palmer   the  ies  ay                 - MATRONICS WEB FORUMS               - List Contribution Web Site  p;                             



	


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