mdredmond said:Has this ever happened to an RV before (wing folding in straight & level)??
szicree said:I think that the Van's demonstrator RV8 had a wing fold up, but I don't believe anybody ever figured out for sure why. I think most figure that it was due to somebody overstressing the airframe by cranking back too hard, but since the aircraft has no data recorder, you can't know for sure. They subsequently stress tested the b-jeebers out of the wing design (very publicly, to their credit) and it passed with flying colors.
mdredmond said:I found that accident . The probable cause was:
"The intentional or unintentional sudden application of aft elevator control by an undetermined aircraft occupant that exceeded the design stress limits of the aircraft. The aircraft gross weight, which exceeded the maximum allowable for aerobatics, and airspeed, which exceeded the maximum maneuvering speed for the weight, were factors in this accident."
So pilot error on that one. That's no surprise...
RV505 said:If I remember there was a wing mod that was supposed to be done on early RV aircraft..
mdredmond said:Has this ever happened to an RV before (wing folding in straight & level)??
It happened to a Zenith Zodiac earlier this year, Zenith's utter silence on the matter sealing my decision to build an RV...
I'm sorry to jump in here, but you're posting some awfully subjective comments. 1. The -8 wing failure *was* due to overstress caused by pilot error (probably the passenger over pulling). It's definite and well documented. 2. Van's subsequent static loading of the -8 wing passed. I would hardly say Van's tested the b-jeepers out of it. It just passed. 3. Do some very basic investigation and read the NTSB report. There was a witness who's comments supported the scenario of overload. Also, the failed components indicated pure overload failure.szicree said:I think that the Van's demonstrator RV8 had a wing fold up, but I don't believe anybody ever figured out for sure why. I think most figure that it was due to somebody overstressing the airframe by cranking back too hard, but since the aircraft has no data recorder, you can't know for sure. They subsequently stress tested the b-jeebers out of the wing design (very publicly, to their credit) and it passed with flying colors.
Low Pass said:The -8 wing failure *was* due to overstress caused by pilot error (probably the passenger over pulling). It's definite and well documented.
Also, there was recorded flight (airspeed) information. It was a VM1000 system as I recall.szicree said:I stand corrected. Can you tell me where I can find the documentation of the over pull?
RVWanabe said:I have a buddy building a 601XL. He called the factory regarding the fatal accident mentioned on this post.
The 601 failure was due to the plane being assembled at the airport...and the pilot using non graded bolts to attach the wings to the fuselage. I would not consider that a design flaw. Ivan/Sugar Land, Texas.
Two reasons come to mind. First, Van lost a friend and co-worker in that accident and if I were him, I would want to know what caused the wing to come off. Was it an engineering error, construction error, what?szicree said:... The NTSB report cites an overpull as the "probable" cause, so I don't see how we can rightly use a term like "definite". Further, if it was "definitely" caused by a pilot error, then why spend all that time and money to stress test the wing?...
N941WR said:Two reasons come to mind. First, Van lost a friend and co-worker in that accident and if I were him, I would want to know what caused the wing to come off. Was it an engineering error, construction error, what?
Second, Vans had a lot of time and money in the "new" RV-8 and its wing design. The stress testing they performed, the openness in which they preformed it and published the results helped keep the business afloat.
N941WR said:Two reasons come to mind. First, Van lost a friend and co-worker in that accident and if I were him, I would want to know what caused the wing to come off. Was it an engineering error, construction error, what?
Second, Vans had a lot of time and money in the "new" RV-8 and its wing design. The stress testing they performed, the openness in which they preformed it and published the results helped keep the business afloat.
As for the test, Vans bought a set of wings from a builder who lost interest in building and used those wings for the test. The thinking was that user built wings might not be as strong as a pair built in Vans' shop. Turns out they were much stronger than Vans' ultimate (yield) design load calculations. Unfortunetly I don't remember the exact number.
mdredmond said:Has this ever happened to an RV before (wing folding in straight & level)??
It happened to a Zenith Zodiac earlier this year, Zenith's utter silence on the matter sealing my decision to build an RV...
Steve buddy, I have about a grand of time in RV-4's, just be careful, when you have a passenger the stick forces get very very very light. I had flown quite a bit solo acro in the dash 4. I remember the first time I did my normal 3 g pull-up with a passenger, I over shot quite a bit, say 4.5 g. Also landing you can't flare too much, you almost hold forward stick to keep the tail off, depending on speed. My RV-4 was at the fwd CG limit solo BTW. Just be careful.szicree said:Having read everything I can about it, I'm pretty sure they got it right, but I also know that smart people get things like this wrong sometimes.
gmcjetpilot said:Lesson is just don't let anyone play with your stick.
there you go, thats my thought as well.f1rocket said:If I can't see them, they aren't touching the controls.