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Unwanted Hole in Wing Spar

mikemalone

Active Member
Any Ideas on how I can fix this mistake? The nut plate holes are for attaching the most inboard leading edge rib to the wing spar. As you can see, the extra hole impinges on the nutplate attachment hole. Could I just fill the unwanted bigger hole with a flush rivet and carry on building?

IMG_0342.jpg
 
My personal (note) opinion is that you can just deburr the hole and attach the palte nut at a different angle.
 
Not so sure about the edge distance between the two large holes. Probably worth asking Vans of their opinion.

Dan
 
Do the same edge distance rules apply when the hole is for a platenut vs a rivet? I'd think it wouldn't be as critical since the screw/bolt doesn't put the same sort of force on the hole that a rivet would. Then again, I'm just a builder, not a designer. :)
 
Not too bad.

Any Ideas on how I can fix this mistake? The nut plate holes are for attaching the most inboard leading edge rib to the wing spar. As you can see, the extra hole impinges on the nutplate attachment hole. Could I just fill the unwanted bigger hole with a flush rivet and carry on building?

IMG_0342.jpg

I would open the upper right somewhat snowman shape set of holes with a unibit until it becomes one bigger hole with no stress risers. Improvise the new attach points. Maybe use a one legged nutplate
 
Do the same edge distance rules apply when the hole is for a platenut vs a rivet? I'd think it wouldn't be as critical since the screw/bolt doesn't put the same sort of force on the hole that a rivet would. Then again, I'm just a builder, not a designer. :)

I have wondered that same thing. It seems like some of the bolts that we put through the longerons etc. would violate the edge clearance distances. I never really measured, but I assume that bolts don't put outward stress on holes similar to rivets.
 
My personal (note) opinion is that you can just deburr the hole and attach the palte nut at a different angle.

I agree - just rotate the nutplate so its 2 attachment holes are at 90 degrees to the existing holes, and install it. Just debur the 2 excess holes and leave them as is. I don't think that the extra holes will weaken the spar, and filling the excess holes with a rivet will not strengthen the spar or make any difference, other than aesthetics.
 
Thanks for the replies. I like the idea of possibly fitting a corner nutplate (2 lugs at 90 angle) or even a single lug nutplate. Still awaiting advice from VANs. Anyone out there know of the designation of such parts, the equivalent to a K1000-3 platenut in original plans for an AN3-4A bolt.
 
OMG are you guys serious??

Yes the edge distance on one hole is 3 microns off 'standard'...on a part that has two other bolts holding it on...which is one of 7 parts just holding the back of the tank...

Right guys...I think as soon as that airplane left the ground it would flip over and nose drive straight in! :eek:

I don't know how any airplane from 1903 to 1940 ever left the ground!!
 
Yes the edge distance on one hole is 3 microns off 'standard'...on a part that has two other bolts holding it on...which is one of 7 parts just holding the back of the tank...

The tank attach isn't the problem. The problem is that the spar web here is one of the most highly stressed places on the airframe. That particular spot carries a bending moment imposed by half the weight of the aircraft (at one G). And it sees some of the worst abuse at the hands of turbulence.

You should definitely ask Van's about this one.

Are those pencil marks near the center hole?
 
The tank attach isn't the problem. The problem is that the spar web here is one of the most highly stressed places on the airframe. That particular spot carries a bending moment imposed by half the weight of the aircraft (at one G). And it sees some of the worst abuse at the hands of turbulence.

You should definitely ask Van's about this one.

Are those pencil marks near the center hole?

Thank you Chip, my sentiments as well, the spar is no place to be making arbitrary repairs, "it should be ok" don't cut it here.
 
pencil

The tank attach isn't the problem. The problem is that the spar web here is one of the most highly stressed places on the airframe. That particular spot carries a bending moment imposed by half the weight of the aircraft (at one G). And it sees some of the worst abuse at the hands of turbulence.

You should definitely ask Van's about this one.

Are those pencil marks near the center hole?

The point about the pencil mark is, for some of us that aren't aware, "graphite and aluminum are not compatible".
A real source of corrosion is possible. All starting with a seemingly innocuous pencil scribe.
 
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