So who to believe? Aviation engineers, aircraft designers and people actually doing structural testing – or – the internet ? 
In all honesty though, I cannot say I like this “normalization” of acceptance of cracked parts. A builder doesn’t have the resources, time and equipment to test like Vans are doing. A builder has to rely on his eyes and feeling by hand to determine if it’s OK or not (crack vise). A true and trusted method. Even if it should lack in scientific evidence, it is a conservative method that puts the soul at rest. But, this was a one off, a mishap. It will never happen again in a hundred years IMO, and in that sense I would go with Vans here.
Thinking (or dreaming) of cracks:
Before anyone starts speculating about the work Vans have done doing these tests, watch this video from 4 true aviation engineering heavyweights who visited Vans and have gone through all their work.
LeSving wrote:
4 true aviation engineering heavyweights
Not exactly how I would describe them… more like people indirectly employed by Van’s, brand fanatics, and a gang of good old partial friends.
We are, ladies and gentleman, very lucky indeed! Lucky in that aviation is experiencing a revolution of which we are the witnesses.
Aluminum airplane building has been done for more than 100 years (the Blechesel probably being the first), and today, thanks to Van’s, it has now been proven that cracks don’t affect structural integrity. Great news, though I’m not sure what other kit or aircraft manufacturers will make out of it…
Despite these fantastic revelations, I will continue to abide to the multiple SBs affecting most RV models and relating to cracks, e.g. SB-00036 Inspect outboard elevator hinge on the horizontal stabilizer rear spar, replace if cracks found, SB 16-03-28 Cracking of wing aft spar web at the inboard aileron hinge bracket attach rivets, SB 14-02-05 Cracks in Elevator Spar, SB 14-01-31 Horizontal Stabilizer Cracks…
Dan wrote:
Great news, though I’m not sure what other kit or aircraft manufacturers will make out of it…
Well, Boeing seem to be copying Vans…
Not exactly how I would describe them… more like people indirectly employed by Van’s, brand fanatics, and a gang of good old partial friends.
Of course you are right. Having worked all their lives at the very spear end of NASA, and so on and so forth is nothing compared with the unsurpassed intellect of the average internet hero
Despite these fantastic revelations, I will continue to abide to the multiple SBs affecting most RV models and relating to cracks, e.g. SB-00036 Inspect outboard elevator hinge on the horizontal stabilizer rear spar, replace if cracks found, SB 16-03-28 Cracking of wing aft spar web at the inboard aileron hinge bracket attach rivets, SB 14-02-05 Cracks in Elevator Spar, SB 14-01-31 Horizontal Stabilizer Cracks…
Did you even watch the videos?
@LeSving wrote:
So who to believe? Aviation engineers, aircraft designers and people actually doing structural testing – or – the internet ?
Some people chose the trust but verify method over blind trust. People that are affected by this might be paying attention to the small details that you may overlook. Such as their switching definition of Primary and Secondary Structure.
For the longest time Van’s claimed they were suggesting replacement of all laser cut Primary Structure in order to seam like they were inline with FAA guidance. Now they are calling the same parts Principal Structure Elements. Which is definitely closer to the truth.
People lose faith when it is clear they are being deceived. The only other option is they really are incompetent.
RV8Bob wrote:
Some people chose the trust but verify method over blind trust.
Which is exactly what Vans have been doing. Tons and tons of tests. Then, if you watch that video, you will find 4 super high competent persons discussing the work Vans have been doing. They have been given time to study their work, and they have been at Vans first hand to see for themselves how they do it. They give Vans the thumb up.
I have been working as an engineer all my life (PhD). Not in the aviation industry, but in the energy sector, turbines and powerplants as well as all kinds of related stuff, also in the oil industry. I also have more than a decade as lecturer at the University (part time) and have worked for several years at a private research institute. I would say I have developed a pretty good nose for recognizing good engineering work and good engineers when I see them. The people at Vans, and the work they have done checks all the boxes. Even the part where they were given a “D minus” for communication is a true sign of good engineers Those 4 guys in the last video, they need no further verification of competence by anyone, their CVs speak for themselves. That, and the fact they have been in experimental aviation all their lives.
IMO this as as rock solid as it gets in any kind of engineering circumstance. Even in a court of law (which happens all the time), this is as solid as it gets. Only complete morons would try to make a case against Vans here, and they would lose, 10 out of 10 times. Not that this particular case has anything to do in a court of law, but the principles of it would be similar.
As far as I’m concerned this case is closed. The lid is on, and the nails are firmly hammered down (with proper edge distance ) Some people will of course never let it go, but that’s their problem. They will never let it go for the same odd reasons that some people believe the earth is flat, man never walked on the moon, vaccines are full of 5G nanoparticles and so on. Nothing will change their opinions, hence there is no point in further discussions.
Sure, great speech, but I would really like to know if and where Dr. Engineer LeSving worked on any nuclear power plant so I can make sure I don’t live downwind of it.
Producing parts that are worse quality than what you did before and what is industry practice, up tl and including cracks, is bad enough. Trying to play it down for as long as they did is the real problem, it destroys trust and I can’t blame people who don’t listen to a word anyone who is connected to Vans says, even if by now they seem to have mended their ways.
