Graham wrote:
… 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.
…and the Challenger space shuttle.
I doubt any of the three was done to save money. Just cockups, due to bad QA and lack of expert engineering input.
How about the Toyota unintended acceleration cover up.
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.
They may be right. However if I were building a plane based on both peace of mind and my own financial (resale value) motivation, I wouldn’t use parts with laser cut holes. I’d pursue parallel paths to source the replacement parts, in addition to whatever negotiations are possible with Vans and concentrate on maintaining progress and getting the plane flying. It is the builders plane and the builders project, as manufacturer and not just as a consumer. Also, if Vans is unwilling or unable to satisfy their customers in this regard I suspect others will step in to develop or sell parts or services.
I would not look to any regulatory body or their agents to assist in negotiations with Vans. FAA will not get involved in anything but the most ambiguous and advisory way (it is clearly not their regulatory role for experimental aircraft to do otherwise, and they are disciplined in this regard) and a US company making uncertified parts with no overseas operations like Vans is not subject to the authority of overseas regulators.
Silvaire wrote:
They may be right. However if I were building a plane based on both peace of mind and my own financial (resale value) motivation, I wouldn’t use parts with laser cut holes. I’d pursue parallel paths to source the replacement parts, in addition to whatever negotiations are possible with Vans and concentrate on maintaining progress and getting the plane flying. It is the builders plane and the builders project, as manufacturer and not just as a consumer. Also, if Vans is unwilling or unable to satisfy their customers in this regard I suspect others will step in to develop or sell parts or services.I would not look to any regulatory body or their agents to assist in negotiations with Vans. FAA will not get involved in anything but the most ambiguous and advisory way (it is clearly not their regulatory role for experimental aircraft to do otherwise, and they are disciplined in this regard) and a US company making uncertified parts with no overseas operations like Vans is not subject to the authority of overseas regulators.
I agree fully and likewise will not use such parts. All I will do is pressure and cajole Van’s as best I can, as a customer, to deliver the parts they agreed to supply. My individual bargaining power is low, and I have no thoughts of appeal to any ‘higher authority’, but I surmise that there is some bargaining power that lies with the customer community as a whole. They need to listen to ‘the herd’ to at least some extent, or their goose will be cooked.
Let’s differentiate a bit, and clarify:
The LCP problem
LCP = Generally speaking no measurable reduction in strength, therefore acceptable
LCP displaying visible (naked eye) cracks after dimpling and/or riveting = reduction in strength, so in principle not acceptable. Accepting the installation of cracked parts in a new build would set off a revolution in the aviation world, or has any other aircraft ever been built with parts with known existing cracks?
Authorities
USA = a generally more relaxed attitude towards aviation in general, great freedom for E-A/B
Europe = each country with its own NAA and set of rules. Quite a few of them have relegated the overview to associations such as the LAA, the OUV, the EAS, the IE, etc. These in turn have inspectors, or builder advisors, following and guaranteeing the build quality.
Graham wrote:
Regardless, the point is that such holes, punched final size or not, don’t crack when dimpled
Not yet, but what will happen after 10-15k h ? A punched hole looks like this:
You have to drill out a substantial part to remove all the residual stress.
Nevertheless, the mechanism of riveted parts is two pieces of sheet metal is held together by friction due to the rivet clamping the sheets together. Any cracking is not likely to propagate unless the rivet looses it’s tension. This can happen due to corrosion for instance or repeated bending of the joint, and so on. If the rivet looses it’s tension, then all the shear forces will be concentrated at the rivet exclusively, and having a crack there to start with doesn’t sound like a good idea IMO. If it actually matter if a crack is there or not when/if that happens, who knows? If it has a potential to crack (fatigue), it will probably crack regardless? It will depend on lots of other circumstances like the loading pattern, the loading amplitude and so on. This is what Vans has investigated, and they have come up with a solution, which parts to replace so the life span of the aircraft is not affected.
Silvaire wrote:
However if I were building a plane based on both peace of mind and my own financial (resale value) motivation, I wouldn’t use parts with laser cut holes
This is a two edged sword. In 5-10 years what people will remember is Vans had some sort of minor problem with laser cut parts, but they fixed it. People will also remember that this made lots of customers angry and upset. Vans is the supreme authority on their kits. There is no doubt about that. They will be that 5-10 years from now also. Any solution to this problem that is not coming from Vans, is not likely to increase the resale value compared with a kit fully built after Vans specifications. Laser cut parts or not will not change this, as long as the fixes are done after Vans specifications. These specifications will be there on Vans site in all foreseeable future. The reason is that people put more trust in Vans than some arbitrary angry and upset customer, because Vans is the supreme authority.
Another thing is that I cannot think of a single civil aviation authority that will put more faith in solutions made by arbitrary angry customers over the solutions by Vans. This could also be applicable to insurance, even if a solution made by someone else is technically better. This is about certainty vs uncertainty. Vans is something tangible and measurable. Everything else is randomness, a big unknown.
LeSving wrote:
Not yet, but what will happen after 10-15k h ? A punched hole looks like this:
Can’t you see what the difference is?
The punched part may indeed be stressed and may conceivably have problems at 10-15k hours as you suggest. But it isn’t cracked when first riveted together and when the aircraft is first flown. The laser-cut part is cracked from day one.
We all know that sometimes cracks start at rivet holes in service. Van’s has a number of service bulletins out on this, with corrective action to take if cracks appear in certain locations. We take a pragmatic, airworthiness-based approach to cracks which develop in service because the alternatives are to replace the part (not always feasible), replace the assembly (often very expensive) or even scrap the aircraft. There is no need to take that approach and accept thousands of cracks in an aircraft structure before it even flies when the simple alternative exists of using parts which do not exhibit these characteristics.
LeSving wrote:
This is a two edged sword. In 5-10 years what people will remember is Vans had some sort of minor problem with laser cut parts, but they fixed it. People will also remember that this made lots of customers angry and upset. Vans is the supreme authority on their kits. There is no doubt about that. They will be that 5-10 years from now also. Any solution to this problem that is not coming from Vans, is not likely to increase the resale value compared with a kit fully built after Vans specifications. Laser cut parts or not will not change this, as long as the fixes are done after Vans specifications. These specifications will be there on Vans site in all foreseeable future. The reason is that people put more trust in Vans than some arbitrary angry and upset customer, because Vans is the supreme authority.
You’re wrong about this, as you are about most things on this issue. Your judgement is way out, and whether they do fix the issue (or even survive) still remains to be seen. Pretty much Van’s entire customer base has spoken and has told them “no dice” on their foolhardy and expensive attempts to justify use of these parts. That’s the main reason they are in serious financial trouble – because almost every affected customer has requested that all laser-cut parts be replaced. Van’s is no kind of authority (supreme or otherwise), it is simply a manufacturer and retailer and frankly at the moment they are the last people I would go to for advice on my build. They are the kit supplier and that’s all they are, to me at least. Trust is at an all time low, and their integrity on engineering issues is clearly compromised by financial desperation.
LeSving wrote:
Another thing is that I cannot think of a single civil aviation authority that will put more faith in solutions made by arbitrary angry customers over the solutions by Vans.
No customers (arbitrary, angry or otherwise) are proposing any ‘solutions’. They’re simply requesting the parts that were advertised and contracted for. Van’s are proposing ‘solutions’ – the main purpose of which is to reduce Van’s financial exposure – and the customers are saying “not good enough, give us what we paid for”.
LeSving, do you have shares in Vans?
Graham has ‘skin in the game’ and from the very beginning has been extremely pragmatic, reserved and well considered with his views/opinions.
I don’t have ‘skin in the game’ but as a potential future RV owner, I have taken an interest in this story.
I can see myself one day looking at several available RV’s for sale. If I see one with cracks around rivets, despite the vendor explaining / complaining, Vans said it’s all ok, I’ll be walking away to look for one without cracks.
If one or two other prospective buyers do the same (which I don’t see as a ridiculous chance) where does that leave the poor vendor?
No Authority or kit part manufacturer is gonna convince anyone cracks are ok.
So Despite what you say, this is a big issue that will hang around for years.
Graham wrote:
You’re wrong about this, as you are about most things on this issue. Your judgement is way out, and whether they do fix the issue (or even survive) still remains to be seen.
What I said was it is a two edged sword. If you believe you can fix this issue better than Vans are doing in full openness, then good luck with that. I think you will have a very hard time convincing people in 5-10 years that you know their aircraft better than Vans, and that Vans solution to this particular problem somehow is not good enough. What exactly is it with Vans solution that you don’t like? It consists of replacing all necessary parts, and then some.
Graham wrote:
Pretty much Van’s entire customer base has spoken and has told them “no dice” on their foolhardy and expensive attempts to justify use of these parts
From what I see, most people already today look at Vans solution and say, OK it’s a set back and disappointment for sure, lots of extra work, long time delays, but to finish this aircraft, to move on, it’s better to work with Vans then against Vans when all things are said and done.
Graham wrote:
Van’s has a number of service bulletins out on this, with corrective action to take if cracks appear in certain locations
For sure. But, take a look at the details. It’s all in the details. Especially the last, and dreaded SB-00036 and also older SB-16-03-28. Cracks appear not because of faulty rivets or bolts or corresponding holes, but due to not anticipated forces and vibrations causing rivets to lose their tension.
Graham wrote:
and the customers are saying “not good enough, give us what we paid for”.
Some customers are obviously saying that, I agree 
Look, I don’t think anyone disagrees with your basic premise that you are entitled to get what you paid for. I certainly do not. This is not the “issue” I have with you. The “issue” I have is this focus on making Vans look bad to justify yours, and lets be honest here, minor problems of replacing a few parts. Even if it costs you US$ 1k or at max 3k for a set of brand new all punched parts replacing every LCP part, this is peanuts in the big picture. People do make mistakes, Vans also. When you buy a kit from any kit manufacturer, you effectively enter a marriage. As in a normal marriage, the best thing to do is to stay together in bad days as in good days. The normal customer-consumer relation doesn’t work all that well here. You are a customer, but you are also a builder. Which one of those two hats is the most important when manufacturing this aircraft? I hope you get your stuff sorted out, I really do. Just don’t believe for a second I ever will agree on your “assessment” of Vans. Also, if you think you somehow can “win” this by repeated personal attacks on me (“unpleasent” and whatnot), you are also wrong.
