FNG Newbie Alert! New LE Rebuilder

[Dan_]

Thanks!  Yes.  Indeed it did, but it is a materially different link this time compared to the first...

[Victor Bravo]

Can anyone with knowledge please address the structural flight safety question I posted last night, in Post #26 on this thread?

[Kamcoman77]

I just clicked on the link and it also went straight to Page 20.

[Dan_]

The last link works for me the first one sent did not...  No big deal.

[Dan_]

Can anyone with knowledge please address the structural flight safety question I posted last night, in Post #26 on this thread?

I'm not an engineer, but there are several pieces of wood coming together right there with plywood gussets essentially making them all one piece.

If that is a L.E the wing spars and ribs are pretty much identical to mini-max and have been tested empirically tested.  If it is an XL it was engineered by an expensive licensed aeronautical engineer.  Put the hole where the plans say.

[Victor Bravo]

Those photos are of my LEUL that had been built by someone else and reportedly flown. I do not have any opportunity to re-locate the hole without major structural modification.

I am only asking whether this is the same problem that I had read about in one of the previous threads the other day, and if this problem is a known safety risk.

I did not bookmark or note which thread or post, which I now regret. 

[Chuck in Indiana]

Well.... I was looking at the inside of the wing on my new-to-me LEUL, and I saw something I want to ask the forum brain trust about. I remember reading something on this forum about making sure you do not touch or notch the main spar caps when you're drilling the holes for the aluminum spar root fittings.  On at least one of my wings, it appears that the bolt is "perilously close" to the spar, as had been mentioned on another build thread.

Can someone verify whether the bolt location in these photos is or is not in a safe location? I cannot imagine that the hole for this bolt does not "notch" or weaken the upper spar cap underneath the plywood plate.

*I know nothing about the LE* but I'd say that it's been flight tested. (shrug) If that is what the drawings say to do, I don't see how you couldn't drill through the spar cap.

[Dan_]

Those photos are of my LEUL that had been built by someone else and reportedly flown. I do not have any opportunity to re-locate the hole without major structural modification.

Dunno about the rest of your question but moving the hole is not a problem.  Just plug it with a dowel with epoxy --re-drill.  Simple as that.

The Tailwind guys do it this way when the lift strut holes have to be moved in the main spar.  The Tailwind is a 200 mph airplane.

I would warm the wood and coat the hole as many times as necessary to let it soak in as much of the epoxy as it will and sand and rinse with distilled water.  Same with dowel.

I you like I could try and look up the info from the TW site, but you trust me don't you..?

[Chuck in Indiana]

I took on a Pitts project one time that had a hole drilled in the wrong place. I did essentially what Dan says, although I ground a couple of spiral grooves around the dowel to keep it from pushing all the epoxy out. It's been aerobatted for 40 years..
VB, maybe what you have read is about drilling into the lower spar cap at the lift strut on the XL?

[Victor Bravo]

THANK YOU all for the replies on this. I'm just trying to be conservative, speaking as a non-engineer and a pilot who has probably used up eight of his nine lives doing a couple too many stupid things in my youth   

I looked at the hand drawn plans and it clearly shows the bolt hole to be right on the glue line between the upper spar cap and the heavy diagonal brace, with 1/8" plywood on both sides.

So my initial fear (careless workmanship during the build creating a catastrophic structural flaw) is not valid.

[Dan_]

VB,
One more thought on spar holes... 

It goes without saying I guess, but still better said than not...  

The absolute last thing you want is to have a hole egged out to let a bolt through...  

Dowel it and re-drill the correct size hole in the right place.