Regardless of the DARs the builders are the ones signing the airworthiness certificate. Van’s answers to them, not the FAA. Many builders will stick to the conservative approach when faced with conflicting guidance
All of that is correct, with the clarification that as the legal manufacturer of an FAA Experimental category aircraft whatever technical guidance they may choose to use is up to them, and their satisfaction with whatever they’ve bought from Vans is a commercial issue.
The cursory DAR inspection is irrelevant to this issue and as much as I’m sure many would like to get the FAA involved for their own benefit, and Vans detriment, it won’t happen. FAA Experimental Amateur Built aircraft are the product of their individual builder and are not limited to FAA approved data in their construction.
Graham wrote:
That’s nothing really
For a company that’s de facto bankrupt that’s something for sure. It says every single one will be handled on an individual basis. No one is forgotten. In all my life I can’t remember a single other company that has handled such a chain of devastating events the way Van’s has shown the last months. And it’s all in the open, for the whole world to see. And that video by Van himself, speaking to all their customers, in all openness. Any other company would simply clam up and nothing would be spoken except one or two corporate BS messages by some layers.
taken from another forum (…), these gentlemen do share my opinion on the problem, and raise some interesting issues…
The difference between a B-737 and a RV is a 737 has a service life of 55k+ hours. An RV has 10-15k max due to anodized spars and punched rivet holes. That’s the issue here. Will those faulty laser cut holes reduce the service life more than what the already “compromised” structure is reduced? Probably not. Has any anodized and match drilled RV made it to 10K yet? I don’t think so. Will we ever find out if those laser cut holes will shorten the actual service life of any actual aircraft? No.
It’s time to put this dog to rest 
LeSving wrote:
It’s time to put this dog to rest
Simple exercise. Be honest.
You want to build a kit airplane, and you are prepared to purchase empennage, wing, and fuselage kits. The kit manufacturer gives you a choice between two sets of kits. Each set sells for the same same price and delivers on the same schedule.
Kit set A consists of parts that have all been produced using methods widely accepted throughout the aviation industry.
Kit set B includes 317 parts that have been produced using a method that the aviation industry scoffs at, and, as a bonus, many of the parts are known to have a crack rate in excess of 90% when dimpled.
Which set would you choose?
By the way, I was not given that choice.
Will we ever find out if those laser cut holes will shorten the actual service life of any actual aircraft? No.
It’s time to put this dog to rest
This issue will quiet down eventually but mark my words, it will become something much bigger in the future.
Kit set A consists of parts that have all been produced using methods widely accepted throughout the aviation industry.
Since when did anodized main wing spars and punched holes become widely accepted throughout the aviation industry?
LeSving wrote:
Since when did anodized main wing spars and punched holes become widely accepted throughout the aviation industry?
Punched holes have been around probably since metal aircraft have been made. All of the flanged lightning holes in fuselage frames are punched and formed with a fly press or similar.
I meant punched rivet holes, all the way up to the correct dimension, obviously.
LeSving wrote:
I meant punched rivet holes, all the way up to the correct dimension, obviously.
Punched to final size is limited to the -10 and -14 I believe. Maybe the -12, I don’t know much about it. Everything else is punched about 45 thou undersize and drilled / reamed to final size by the builder.
Regardless, the point is that such holes, punched final size or not, don’t crack when dimpled. The metal surrounding a punched hole has not been hardened and embrittled by the heat of a laser to a point where it can no longer take the stretching which occurs when dimpling. Any builder with both sorts of parts to hand can demonstrate this to you in five minutes.
LeSving wrote:
Will we ever find out if those laser cut holes will shorten the actual service life of any actual aircraft? No.
I really hope you’re right. Van’s seem convinced they know the answer. The question is whether builders trust them based on their obvious financial incentive to come to this conclusion. To anyone who tries to suggest commercial motivations could never affect engineering or safety and that you should always trust the professionals, I say…….. MCAS.
