Spars Cracked (Yes now into the wings)

[Jim Herpst]

Moved into finally cutting open the wings now that everything else on the plane is being covered or as in the tail section ready for cover...did not take long to see what looked like a small crack in the right wing rear spar just beyond the last aileron attach point fitting as heading out board . THEN opened the left wing and found a no doubt big time crack/failure in the same general area as the left. ! Right above the crack I saw a tag as pictured here near a plywood skin glued on the spar above the actual cracked area stating TAC MFG REPAIR. It looks to me like this area had some damage or better yet rejected area on the spar when new and they thought when new and they thought they fixed it. It looks almost like the wood had a felling area of damage to the wood when orginall the tree was cut. The very lower edge showing "crumpling" as in the grain crushed. Wowa. New religion. Wings being gutted. About what I expected. Everything thing else on the plane has been the same story and now as new. Only fitting the wings would of course be the same. In fact i was almost the exact nightmare I figured!

[Mark Bowden]

Good catch and quite interesting with respect to the mfg. repair tag. That tag maybe a quite rare bit of trivia and historical reference. It will be interesting if you can determine what the orginal rejection was and how they did the repair. Taylorcraft certainly glued spars up out of pieces.

Where was this damage located? You mention outboard of the last aileron hinge but it looks more like where the outboard strut attach fittings bolt on. There is an inspection ring hole in the fabric which was never opened up and a cover put in place. If outboard of last aileron hinge then not much load on that part of the wing.

Alway good to see progress and see you planned for this so the suprise wasn't a suprise.

Are you putting in the increased gross weight wing attach fittings?

[Jim Herpst]

Gross weight going to 1320 per the Bowden ST .Damage starts at the aileron hinge bracket. It does not run all the way to the strut attach fitting area. Yes that inspection hole was never opened. Dad and his partner were the last ones to cover it .That was 1967. Sold in 1972. As ratty as it had gotten ALL these covers should have been opened! What is really funny is some genius thought it a great idea to install a plate some time way after it was covered above the middle aileron belllcrank attach point on TOP of the wing which certainly gives one great access there to see the mechanics of it and perhaps lube however never thought to open up ALL the inspection covers below the wing.. No damage was noted to the wing..wonder how long it was like this? The plane was taken down in 1985

[Hank Jarrett]

As Mark said, really low loads outboard of the last aileron hinge area. If you have ever seen a wing bending diagram you can see how it actually tapers off to zero at the tip in straight and level flight. If that is the only damage the spar should be repairable and if it is worse than it looks the old wood in those spars as FAR superior to more modern wood. They would be VERY valuable to anyone wanting to do a clip wing. Any damage to the ROOT end of the spar would be a BIG problem, but that looks very repairable.

Hank

[Jim Herpst]

As Mark said, really low loads outboard of the last aileron hinge area. If you have ever seen a wing bending diagram you can see how it actually tapers off to zero at the tip in straight and level flight. If that is the only damage the spar should be repairable and if it is worse than it looks the old wood in those spars as FAR superior to more modern wood. They would be VERY valuable to anyone wanting to do a clip wing. Any damage to the ROOT end of the spar would be a BIG problem, but that looks very repairable.

Hank

Hank, the "last" aileron bracket is actually the first (meaning the one closest as one moves to the center of the wing). Also, the crack runs from this fitting towards the strut fitting but not all the way to it. Yikes. Not a good area of the wing

[Hank Jarrett]

OK, I'm not clear. Is the split at the bracket closest to the TIP or the root? Any photos of the damage?

Hank

[Jim Herpst]

OK, I'm not clear. Is the split at the bracket closest to the TIP or the root? Any photos of the damage?

Hank

Closest to the root. Page up in the thread for ohotos

[Hank Jarrett]

Yea, that's not good. Sorry I got your post confused with another persons spar split at the tip. Remember the wood from a bad spar is still really good wood! I used damaged spar wood for all kinds of smaller parts on my plane.

[Jim Herpst]

Yes I wish I had all the spar material that has passed through my hands! I would rip it all up and laminate new ones!

[Hank Jarrett]

If someone doesn't have good enough Stitca Spruce you know you can use Douglas Fir (still has to be inspected and is a bit heavier but can be allowed).

Hank

It is also stronger for the same dimensions.

[Jim Herpst]

If someone doesn't have good enough Stitca Spruce you know you can use Douglas Fir (still has to be inspected and is a bit heavier but can be allowed).

Hank

It is also stronger for the same dimensions.

Thanks Hank, Yes aware of the Doug fur. AC Spruce does have Spruce for those following this. I am going a different direction on the wings all together. Back later.