Bob-
I may have misread your post, but from the above portion you seem to imply that you've seen a lot of planes that have crashed due to structural failures that were the result of poor workmanship. Or, did you just mean that the planes you've seen that have crashed from pilot or systems failures just happened to have non-crash-related structural issues as well?
I've seen reports of a lot of planes that have crashed due to systems failures, but I've seen very few RV crashes that were attributed to anything structural, builder-related or not. I'd be interested in being pointed to the results if I'm mistaken.
I think for most builder's there is no correlation between the occasional cosmetic mistake or imperfectly set rivet and the overall airworthiness of the aircraft. Chronic cosmetic or riveting issues may be a different story.
Steve, when an RV breaks up in flight there will be no need to strip it down for repairs....because there will be nothing left to strip down or repair. So the answer to your question is obvious in that the deficiencies I observed did not lead to an inflight structural failure. However having said that, it might also be seen as relevant that I have now assisted in the partial strip down of 3 RVs and each one of them proved to have what I consider to be serious defects in build quality which only became obvious to me as a result of the stripdown.
The fact that these particular RVs (and many other RVs for that matter) did not suffer inflight break-ups given their construction flaws is NOT an indication that they were airworthy....it's an indication that they were probably never pushed anywhere near their specified load limits.
For instance it is a fact that one of Van's staff reported he came across an RV that had NO BOLT AT ALL in a rear wing spar (at the fuselage connection)...so the plane had been flying for an extended period of time with absolutely no connectivity between the rear spar and the fuselage. But of course if that plane had ever been pushed to +6G that pilot probably wouldn't be here today.
Many RV builders are older guys who are simply interested in puttering around in the sky. And most of those who DO any aerobatics confine it to the occasional loop or roll pulling no more than +3G. And in particular those builders with lots of skeletons in the closet probably have enough brains (and sense of self preservation) to refrain from going out to the zone where the wind is whistling and the wings are creaking.
In the end it all comes down to one's definition of an "airworthy" RV airframe. MY definition is that the airframe will repeatedly and safely accomodate the loads as specified by Vans (ie +6G -3G at and below aerobatic gross weight) and be capable of going out to +9G before ultimate failure. Will all RVs do that......I don't think so from what I've seen!!!
As I've said previously the advantage of good construction becomes more important at the edge of the flight envelope....and during a crash (a pilot might survive 15G but the fuselage might not). It will also become more important as an aircraft ages and the stress cycles mount up. At the moment the Vans fleet is relatively young....most RVs have less than a 1000 hours on them.
There have been a number of documented cases of RVs breaking up in flight (Van's own demonstrator RV8 being the most famous) following aerobatic manoeuvres. A local RV4 came down recently after completely losing its empennage during aerobatics.
On top of that we often hear of RV pilots drilling their planes into the ground while performing aerobatics. Usually it's due to poor pilotage, but there's certain to be a number of structural/linkage/control surface failures in there as well. The truth is that the NTSB isn't interested in sending out a team of experts and spending millions of dollars collecting, assembling and analysing the charred remnants of an Experimental aircraft.
But having said all that, I certainly agree with you that construction flaws in aircraft systems is the really big danger.
