dbhill916
Well Known Member
Hi guys,
I'm looking for advice as how to proceed from a major mistake. The first thing I did with my new wing spars was mis-drill the tie down extrusion on the upper surface of the L spar. (I got cocky after the 1st 3 and drilled & tapped with the spar positioned such that extrusion was underneath the spar where I couldn't see everything that I was doing. Learn from my mistake!)
The image is a bit blurred, but you can see that the drill was angled toward the surface the extrusion and has surfaced. For the photo, I re-inserted the tap and you can see it in the surface.
So far, I have identified 3 paths to pursue. Easiest (and therefore of greatest suspicion) is to ignore it and use the tie down as if nothing happened. The threads are intact along the upper (as oriented in the photo) and lateral walls of the long axial hole, but probably non-existent on the lower edge of the hole directly under the unwanted opening. As a total WAG, I guess that there's a 30? arc x 1/2" where there are no threads. Is that lack of contact enough to compromise the strength of that bolt? (What is the function of that bolt, anyway? I'm further guessing that it's to suspend the wing in maintenance actions.)
2nd option is to ignore it completely. That is to say mark the tie-down as InOp and never use it.
3rd option is to re-drill with a larger bit and re-tap with larger threads. To ensure good strength, I would tap 2" to obtain a full inch (original spec) of completely engaged threads. Will there be sufficient aluminum to accept the larger bolt?
Any and all inputs on how to proceed are certainly welcome!
I'm looking for advice as how to proceed from a major mistake. The first thing I did with my new wing spars was mis-drill the tie down extrusion on the upper surface of the L spar. (I got cocky after the 1st 3 and drilled & tapped with the spar positioned such that extrusion was underneath the spar where I couldn't see everything that I was doing. Learn from my mistake!)
The image is a bit blurred, but you can see that the drill was angled toward the surface the extrusion and has surfaced. For the photo, I re-inserted the tap and you can see it in the surface.
So far, I have identified 3 paths to pursue. Easiest (and therefore of greatest suspicion) is to ignore it and use the tie down as if nothing happened. The threads are intact along the upper (as oriented in the photo) and lateral walls of the long axial hole, but probably non-existent on the lower edge of the hole directly under the unwanted opening. As a total WAG, I guess that there's a 30? arc x 1/2" where there are no threads. Is that lack of contact enough to compromise the strength of that bolt? (What is the function of that bolt, anyway? I'm further guessing that it's to suspend the wing in maintenance actions.)
2nd option is to ignore it completely. That is to say mark the tie-down as InOp and never use it.
3rd option is to re-drill with a larger bit and re-tap with larger threads. To ensure good strength, I would tap 2" to obtain a full inch (original spec) of completely engaged threads. Will there be sufficient aluminum to accept the larger bolt?
Any and all inputs on how to proceed are certainly welcome!