Cracks?

[MarkW]

As I was deburring my second set of wing ribs today I started to wonder. I also had just read the thread on life expectancy of a RV.
I did a search and don't find any threads on structure cracks. Van's talks a lot about deburring.
How many planes have had rib cracks that were caused by inadequate deburring. How many builders end up with cracks and wish they had done a better job deburring.
I feel I am doing a good job deburring but don't want to regret that I did not do better.

[donoltman]

I'm with you. My build partner would probably prefer that I didn't spend as much time smoothing every edge and deburring every hole but he puts up with me. As we pull clecos we also ream instead of drill as we install rivets. It may be overkill but I don't want any cracks down the road either.
Don

[Snowflake]

It's a good question. Keep in mind that Van's deburrs rivet lines on skins by running a scotchbrite pad down them.

[MarkW]

Now one has had or heard of cracks in places like ribs corners?

[JonJay]

Cracks are usually caused by metal fatigue, often due to poor design or corrosion. I do not think much of this has shown up in the RV fleet or perhaps ever will.
Early .016 skinned rudders and elevators had some cracking issues but not if they where made correctly, or it certainly reduced the problem. Outside of that, I have never heard of any.
I would hazard a guess that you could build an RV without any prep and it would probably fly for hundreds or thousands of hours without exhibiting any problems. However, that is simply not good practice. The standards we build our machines from where developed 70 plus years ago and have withstood the test of time. Of course, the methods we are using to build them are that old too!

[Kyle Boatright]

As JJ said, some aircraft have experienced control surface cracking.

There have also been cracks in the original RV-10 tailcone (later addressed by a mod/upgrade) plus cracked/broken firewall to longeron weldments in various RV's using conventional Wittman gear.