maybe I have some input. At one time I owned two KR's. one a stock original retractable and the other a pretty turbocharged fixed gear KRIIS. Both handled about the same. Didn't need both. I have never regretted keeping funky old 81JM. Ken got it right the first time.-- Sent from my Alcatel A405DL
KRnet wrote: > I should have mentioned that Ron Wanttaja wrote a Kitplanes article on tail > volume about 20 years ago while I was building my KR2S fuselage, and got me > thinking about that and the KR2's reputation for being pitch sensitive in > flight. He created a chart with about 20 airplanes on it, along with their > calculated horizontal tail volume coefficients. If the KR2 was added to that > list, it would have been dead last by a large margin, with the KR2S somewhat > better, thanks to the extra 14" bay that was added. I have that chart saved > somewhere, and will post it when I come across it again. > > Now I'm not saying that KRs are unflyable, not at all. I just thought I'd > stack the odds in my favor while I was building mine, and am quite happy with > the results. Any plane as small as these is going to be more sensitive than > a larger plane (all other things being equal), but the small tail makes it > worse. Widening the horizontal stab is enough enough....you can do it with > mere foam and carbon fiber like Troy did. It's arguable that a stress riser > is created that would increase stress of the horizontal stab spars, but if > you put enough vertical force on that tailplane, you are already done for, I > suspect. > > Mark Langford > m...@n56ml.com > http://www.n56ml.com > Huntsville, AL > > On 2/4/2021 8:50 AM, Mark Langford via KRnet wrote: >> Larry Flesner wrote: >>> > Questiion. Was and by how much was the tail area enlarged in the 2S >> >> > over the KR2? Mark, was your tail volume enlarged over the 2S? If >> > anyone has the numbers I'd be curious how my standard KR2 tail area on a >> > 24" stretch fuselage compares the the 2S. > >>> Yes, my plane is more stable as a result of the longer horizontal stab, > >>> plus the extra few inches added to the fuselage, and the more forward > >>> sweep to my wings (due to adapting the new airfoil to the existing > >>> spars). See the link below for details and how to figure it out. >>> I calculated all that stuff for the KR2 vs the KR2S twenty years ago > or >>> so, but am too busy (and lazy) to do it again. I got this from > Pazmany's >>> book, which the link below refers to. I can definitely say > that my KR2S >>> (and most others, I'm sure) is a lot more stable than the > KR2 that I'm >>> now flying, and the KR2 has a "forward of center" CG almost > all the time. >>> See link: >> >> https://www.eaa62.org/technotes/tail.htm#:~:text=For%20the%20Vertical%20Tail%20Volume,area%20and%20b%20%3D%20wing%20span >> > > > Mark Langford >> m...@n56ml.com >> http://www.n56ml.com >> Huntsville, AL > >>>> _______________________________________________ >>> >> Search the KRnet Archives at > >> https://www.mail-archive.com/krnet@list.krnet.org/. >> Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. >> see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to > change >> options. >> To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org >> _______________________________________________ > > Search the KRnet Archives at > https://www.mail-archive.com/krnet@list.krnet.org/. > Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options. > To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
