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I don't think your group should be stunned. It is common practice to not specify torques when the value is not a critical one. In that case, the values in AC43.13 should be used. In the case of the wing bolts, the joint is not tight tolerance, nor critical. It's only necessary to torque the bolts to "standard" values for that size fastener. I use manuals for many different aircraft and it it is rare to find torque values - sometimes torques are given for fasteners that should be torqued very lightly, or when the fasteners are pre-lubricated. David N6359V A J DeMarzo wrote: > > ----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- > > Here's a good question that has had the N. Texas Coupe Group stunned for > years: Where, in any of the manuals, does it state the torque values for > the wing bolts? Something to look for instead of opening presents! > > Have a Great Holiday and a Safe & Happy New Year! > Al > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > Subject: Re: [COUPERS] loose wing/bolt madness > > > The Alon parts manual calls for a standard AN bolt for the wing attach > > fittings, and I think all the other models of the plane use the same bolt. > > By definition, a standard AN bolt is not a close tolerance bolt - so the > fit > > of the bolt in the wing attach fittings is not critical (within certain > > limits, of course). The wings are held tightly in place by the torque on > the > > bolt. The torque on the bolt develops friction between the "plates" of > the > > wing attach fittings. The friction between the plates is what keeps the > > wings from moving. > > > > If the holes in the wing attach fittings are worn, or if the bolts are > worn, > > then at some point in the life of the plane, those bolts were not torqued > > properly. If they were torqued properly, the joint would have no relative > > motion in it (because of the friction between the plates), and the parts > > would not have been able to move causing the wear. > > > > If you hear a clunk when you lift your wing, and IF that clunk is coming > from > > the wing attach fittings, then in all probability it is because the bolt > is > > not properly torqued. > > > > The design and theory behind bolted joints is thoroughly discussed in > > mechanical engineering text books if anyone wants to look it up. > > > > And of course.... all of this is just my opinion, so take it for what it's > > worth. I would consult with an aeronautical engineer before I did > anything > > to change the design of the wing attach joint. In my opinion, if worn > parts > > are found, then they need to be replaced with factory original parts, not > > rigged with sleeves or wrapped with shims. > > > > Good Flying, > > > > Wayne DelRossi > > __________________________________________________ > To unsubscribe from this list please send mailto:[EMAIL PROTECTED] > > ___________________________________________________________ > T O P I C A http://www.topica.com/t/17 > Newsletters, Tips and Discussions on Your Favorite Topics __________________________________________________ To unsubscribe from this list please send mailto:[EMAIL PROTECTED] ___________________________________________________________ T O P I C A http://www.topica.com/t/17 Newsletters, Tips and Discussions on Your Favorite Topics
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