Notching the aileron nose skin for pushrod attach bolt

[Loman]

I didn't realise that the A-901A aileron nose skins were handed. I didn't notice it at the time but they must have been. The part designation doesn't tell you this, but there is a section in the manual that says" Note that a small notch must be filed in the INBOARD A-904 nose rib" (my emphasis).

With Murphy's law operating smoothly, I have managed to get these notches on the outboard ends. No big problem, you might think - just notch the other end. However I am concerned at the size of the notches required and their proximity to one of the rivets.

The hatched area shown is a little generous (marked with a normal washer instead of a thin one) but it still does not leave enough edge-hole clearance

The notches are definitely needed. There is no other way to get a nut and washer onto the threads of the flat-head screw that serves as an axel for the pushrod end-bearing. It seems my options are:

A) just notch it and forget it - there is plenty of strength left in the remaining fixings that hold the parts in place.
B) put in additional rivets above and/or below the notch, in line with the other rivets and with proper clearance to all edges . It would not be easy to dimple these holes but it is possible

What do you all think?

 

[Vlad]

stick to the plans

Loman,
You marked the notch too wide. Reduce it to the point approximately 3/32 distance from that rivet. I removed/installed my ailerons couple times while rigging and had no issues to put nut on. You have to trim that screw to right lenght. In Murphy's manual it says - get extra screws I cut it three times and the thing was still short...

 

[scard]

Also, note that the nut called out there is a thin nut.

 

[cln1owner]

Not much needed...

The skin doesn't need much of a notch. It does use a thin nut.

 

[Loman]

Sorted!

Two replies within 40 minutes, and another (with photo) 4 hours later! Well done guys; you are all really sharp today!

The key piece of information is the thin nut, which I had missed. One of them had alerady been used inadvertently elsewhere but I found it quickly enough and swapped it out. They made a big difference as you can see:

The old blue line is where I originally intended to finish the notch.

The edge of the notch is a full 3/16 inch away from the dimple of the rivet, i.e. two rivet thicknesses and full edge clearance.

Thanks to all for the great replies.