cracks in champ spar

[Richard]

I purchased a deceased friend's champ, and received an expensive surprise from my IA. It has several cracks in the forward spar near the lift strut. I called about getting a new spar from a dealer, and he told me that too many mechanics are switching out spars when there is no problem with them having small cracks as long as they go along the grain. I'm caught between two opinions. Any ideas?????

Richard

[flyboy1964]

If it were me I would change it. It is your ass in the sky. You might not have a choice because you might not find anyone to sign it off the way it is. Just my opinion.

[MikeB]

In my opinion, a crack is a crack. Having said that, some of these old timers have been flying with horizontal cracks along the grain for a long time but it does have to change the integrity of the spar. Some out toward the tip are able to be patched and plated. I'd be suspecious of anything near the strut attach point as that kind of smells of a possible ground loop and wing drag which puts stress in a critical area. One other thing, be sure your IA is not looking at the spar laminations. The original spars were built with various pieces 'laminated' together to form the spar. Also, be sure the IA is not looking at a horizonal scratch caused by dragging the rib during the installation process.

For your info, I had a fairly long (8 inches or so) horizontal crack in my L16 project coming out of a rib nail hole. I opted to replace the spar.

MikeB

[MikeB]

Here's the actual crack on my spar. As I mentioned it started from a nail hole and progressed both way. Was a little hard to see initially but obvious once I was able to work the spar.

Mike

[Richard]

Thanks Mike for the picture. My spar has two cracks, like those in picture, that start at plywood plate. On the other side of the lift strut there is a long crack that starts at nail hole. The small nails are pulled out of the ribs in that area.
I'm going to have the IA go ahead and replace the spar.
Rainbow Ron, at Moses Lake WA, is nearby so I'll try one of his spars.
Richard

[joea]

Rich,

The spars are 70 years old and if they show any signs of distress would go ahead and change it out.

Will it fly and fly safely for years to come? Probably but why take the chance.

Joe A