Broken gusset plate...

Anyone seen this before? This is an older 1200 hour airframe.



No problem repairing, just wondered what may have caused it so it can be prevented in the future. The lower firewall mounts were changed to the stronger pieces by the previous owner. Were the uppers also beefed up and these possibly not changed? Prudence says I should change both uppers while doing the repair. If upper mounts were also beefed up along the way, I'll be ordering both tomorrow!
Thanks for your comments!

I've seen it before, on an RV-4 that had the early weaker parts.

Too many harsh landings can do it too, especially if operated off rough grass runways.

WD-402 brackets

The new upper brackets are similar to the new lower brackets. They are made from much thicker material and are not split between the webs.

Naturally, the rigidity of the new webs makes them unable to flex into position, so when making the repair, care must be taken to ensure the brackets fit flush on all contact faces.

As you are making the repair, you might also want to check the squareness of the firewall and engine mount, as you may find one or the other is tweaked.

M

Thanks!

Going by the airport tonight to make sure the lowers are the new style. Order necessary parts for the repair this evening.