Revision 9.9.13

[SvingenB]

The revision found here: http://www.sonexaircraft.com/documents/ ... wholes.pdf

Has anyone found out what exactly to do? It is completely fuzzy to me: 1 what is wrong in the first place, and how do I find out. 2 what exactly is the correct place to put the angle, and how do I measure it? What about the bolt holes? are they OK? In the drawing it looks like they also are moved, which will require new parts. I have asked Sonex, but did not get any wiser. I have asked again, but, I guess some of you here already have made this change.

Thanks

[Bryan Cotton]

It looks like bad CNC holes - a mistake in design or parts fabrication. It does seem like a typical Sonex response - add rivets elsewhere to ensure the shear loads are carried. From an engineering perspective it is probably fine. It is similar to my issue of a Sonex #5 vertical for the Waiex application. I would rather have clean parts though.

[Don_P]

The Onex revision of 9/9/13, which changed the hole locations in the rear spar attach angles (ONX-W10-03R/L), was made to better align the root rib and doubler plate with the rear spar. To implement the revision, Sonex offers two options: 1. Move the existing attach angle to the new location and attach it by drilling a whole set of new holes; or 2. Make a new attach angle and mount it using the existing holes in the root rib and doubler. On my project (Onex 0095), I elected to drill out the old part and to fabricate a new one (on both outboard wings). The Swiss-cheese approach just did not appeal to me. This was not that difficult of a problem. When you fabricate the new part, leave off the holes that mate the angle to the root rib and doubler. Then clamp/bolt the new part in place (in its new, correct location) and use the holes in the root rib and double as a pattern to drill through into the new attach angle. Implementing this revision did a couple of things for my project: 1. The wing skin, where it comes off the root rib flanges (top and bottom), is much better aligned with the flanges on the rear spar; 2. The rear spar is no longer under strain from having been forced into a misalignment with the root rib and doubler. Also, taking the strain off the rear spar improved the fit of the aileron and made it easier to remove or insert the piano hinge.

[SvingenB]

Thanks Don-P

I get what I have to do. But nowhere in the SB does it say how to align things up to achieve the correct angle or whatever is supposed to be aligned. I'm away from my shop, and will be for another week, but my parts went together just fine, and looked OK although I did not look for anything special in detail. What measurement shall I take to see what is wrong, and how much, and consequently to get it right? I have not started with the skins yet.

[Don_P]

Svingen,

Implementing the ONX-W10-03R/L part revision will lower the inboard end of the rear outboard spar by about 1/8 inch (in relation to the root rib/doubler). The important thing about positioning the new attach angle is to align it (once it's bolted to the rear spar) so that the center (the up and down center) of the rear spar is centered on the trailing (vertical) edge of the root rib. You can also check the alignment by putting a straight edge along the rib flange and checking to see that is runs directly onto the spar flange with no gap.

If you haven't fitted on the outboard wing skin, there is something else of which you should be aware: On my kit (0095), the middle wing skin was 5/64 inch too wide. To get it to fit inside the double plate at the root rib, it was necessary to grind down the full length of the inboard edge of the skin by that amount (I used a sanding drum on a Dremel tool). Sonex may well have corrected this problem on later kits. You'll know if you have this problem if, when you cleco the skin to the rear spar, the inboard edge of the skin will not drop down inside the doubler plate.

[Mike53]

.Maybe a one of or a few ?as my kit #80 fit perfectly.I think it's just the nature of kits in general.I have had parts where the holes are misaligned .Everything Sonex sells in there kits are made out of house and there are bound to be mistakes in stampings and cutting of stock at the vendors that make them.Ideally mistakes should be caught before they are shipped but in the real world mistakes are inevitable.

[SvingenB]

OK, I think I get it now, thanks. It is still not 100% fixed though. It can be moved in x and y direction, but also rotated. But I think this is close enough.