Forward wing bracket platenut

[Camillo]

Hi.
I forgot to attach the platenut on the forward left wing attack bracket. I noticed that when I mounted the right one.
Now, I would not like to disassemble the fuselage attach bracket, which would be necessary in order to achieve space to install the platenut.
I was wondering if a standard nut instead of the nutplate would be ok or if for some reason a platenut is the only way (for instance, for lower resistance should the wing go off in an accident).
Thanks.
Camillo

[roee]

Camillo,

I'm assuming that you're talking about the fuel tank support bracket, and I'm assuming that on the -9A it is similar to the -7A.

I think it is important that you install the nut plate exactly as shown on the plans (and pay attention to the orientation of the legs of the nut plate). In the event that the wing is pulled off in an accident, the nut plate will help keep the bolt stationary at a right angle to the brackets, which should allow them to slide apart cleanly. If you use a standard nut instead, then in the same scenario the bolt will more easily tilt, which may cause it to bind the brackets instead of allowing them to slide apart cleanly. If it binds and keeps the brackets from sliding apart, then the inboard rib of the fuel tank will be torn open, and then bad stuff can happen...

Anyway, what is the big deal about removing and reinstalling the bracket on the fuselage side? It is only two bolts. Should take less time than reading this message.

Good luck
-Roee

[Camillo]

Thansk-you, Roee. You're right. I will install shortly that platenut.
Camillo

[IowaRV9Dreamer]

The last sentence in the instructions for the fuel tank bracket say...install the plate nut in the T-905 fuel tank bracket. Note the orientation of the platenut, it is important.

Why? Do they mean that it is important that the platenut goes on the correct side of the bracket? Or that the platenut is horizontal?

If I put it horizontal, I may not be able to make edge distance on the outer rivet. I don't see why horizontal orientation is important.

[rvbuilder2002]

Originally Posted by IowaRV9Dreamer

If I put it horizontal, I may not be able to make edge distance on the outer rivet. I don't see why horizontal orientation is important.

Positioned horizontal provides the most resistance to the bolt tilting/binding from the friction load as Roee correctly described above.

In this case, proper orientation of the nutplate is much more important than rivet edge distance (which is not really a factor considering the low load on the rivet and the thickness of the bracket).