Hello,
New to this site.
Thanks,
Rick
Hello,
New to this site. Am more than considering building RV-8. Only concern is design of main wing spar. Is anyone aware of sites, (or entries here) talking about Main wing spar design improvements, that have been done, are being considered, anything?
Thanks,
Rick
Thanks all for your replies.
I have been looking at the RV family for years as a way to get into aerobatics, combined with having a plane with a little extra speed for long distance trips. The 8 has always come out on top when compared against other options (most of my time is in small Cessnas). Having recently sold my plane, I am getting antsy to start on a project, and am still convinced the 8 is the plane.
Regards,
Rick
...To Sid Lambert's question... "You think it just 'looks' weak?" Simple answer is yes. I looked at one under construction last week...
Please understand here the concern is not the "wing spar", but the CG range / stick force per 'g' and low VA of the RV range. So re:My concern stems from having very little aerobatic experience, and so when I start, mistakes will be inevitable. I don't yet know the full story of the factory 8 mishap, but I have heard it involved the demonstration pilot giving the stick to the prospective buyer in the back, who then proceeded to overload the wings. Mistake.
and the RV range, please do not "learn" aerobatics in an RV. it is a "poor" aerobatic trainer for a number of reasons, which end with the fact it is easy to overstress.from having very little aerobatic experience, and so when I start, mistakes will be inevitable
All (aerobatic) RVs are designed essentially to the same principle - design load +6/-3g, ultimate load + 50% on that e.g. +9g, at aerobatic gross weight (for the benefit of doubt, IMHO that includes wing fuel). If you pull more g than that, or pull that g at more weight, the wing will fail - as it is designed to do. It is not (nor should it be) "over designed".To Sid Lambert's question... "You think it just 'looks' weak?" Simple answer is yes. I looked at one under construction last week, while hearing the story of the factory mishap from the individual showing me the spar. When I compare the wing load ratings of the RV-4 against the those of the 8, it prompts me to ask why the big difference?
...which end with the fact it is easy to overstress...
Personally, I think that there are a lot more important things to worry about when building an RV-8. Things like the integrity of the fuel plumbing and the electrical system probably probably have a much greater impact on the overall safety of the aircraft.
Thanks, Bob K.
Here's the NTSB report on the factory demonstrator:
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001211X10121&key=1
Keep in mind 6g is quite a bit, and while I can't find a definitive source at the moment, I think a typical human without a g-suit will blackout around 6g's.
Here's the NTSB report on the factory demonstrator:
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001211X10121&key=1
Towards the bottom of the full narrative you'll see they tested another wing to +6g with no deformation occurring, and then to +9g for 3 seconds without failure but with some deformation.
The wing is more than strong enough for what it's designed for, but that doesn't mean it's indestructable.
Keep in mind 6g is quite a bit, and while I can't find a definitive source at the moment, I think a typical human without a g-suit will blackout around 6g's.
If you ever looked at the inside of a C-172's wing, you would never ride in one again!...To Sid Lambert's question... "You think it just 'looks' weak?" Simple answer is yes. I looked at one under construction last week, while hearing the story of the factory mishap from the individual showing me the spar. When I compare the wing load ratings of the RV-4 against the those of the 8, it prompts me to ask why the big difference?
Regards,
Rick