As an info-sharing list for experimental aircraft designers and builders, this KRNet discussion about the proportions and arrangement of the KR empennage is the essence of why I'm still here after 28 years or so. This sort of discussion is what led to the development of the KR-optimized airfoils and other things specific to the KR, but the methodology is applicable to most other fixed-wing aircraft as well. Very useful, IMHO.
Having worked as an engineer at an R&D outfit for 10 years and seen lots of things developed and refined in many different ways, I think I can summarize the way I see the two main forks in R&D as (1) analyze, design, and then test for verification; and (2) "try it and fly it" (also known as "that looks about right", or TLAR, or the duct tape method). Jumping directly to TLAR can get you very far ahead in the development process and then analytical refinement can pick up from there to get the anomalies and irregularities out of it to get to the finish line. Conversely, careful analysis and design using simulation and models from the very beginning are what got the KR airfoils to the finish line before anything was done at full scale and with someone's neck stuck out as a test pilot. On either of the two forks of R&D on the KR, there is a huge, huge benefit to having the testing done by KR pilots who have a lot of flight experience in these airplanes, because MY sense of "it started requiring quite a bit of forward stick to hold altitude when it got above about 150 MPH" may be somewhat irrelevant empirically if it's put up against a long-time KR pilot saying "they all do that". On the other hand, it also raises the question, "WHY do they all do that?". Obviously, builders who have their own completed and flying KRs are at an advantage over those of us who just sit here at the keyboard, running analytical programs and snooping through aeronautical testing reports to figure things out. On the other hand, how many KR pilots who have their own planes want to start hacking them up to try out some new change or modification or improvement? Sure, a wingtip scrape or off-field incident or something else can provide the opportunity to try something you've been thinking about, but it still takes courage to put the Dremel to that fiberglass skin or to start disconnecting your engine and accessories to pull the whole thing off the firewall just to make an improved engine mount with a few degrees of offset in it. Oscar Zuniga Medford, OR ________________________________ -Please see LIST RULES and KRnet info at http://www.krnet.org/info.html -Change list delivery options at https://list.krnet.org/list/krnet.list.krnet.org/ Affinity List Info Board -Search recent KRnet Archives at https://list.krnet.org/empathy/list/krnet.list.krnet.org/ -Search John Bouyea's decades of archive at https://www.mail-archive.com/krnet@list.krnet.org/
