My KR-2 is plans built. However, it has Diehl wing skins that does extend the total span by 30 inches. The wing taper is greater than stock plans. I am sure that the Horner tips and winglets also effect the MAC. The Diehl tail group probably has some extra weight beyond the stock plans. Bottom line here is: the MAC and center of lift on my KR-2 is probably about 2-inches further forward than the stock plans callout. And still, I used the stock plans MAC callout for cg calculations. Been doing a lot of soul searching on this stuff lately. Having near death experiences in this machine will do that to a person. So, taking Larry Flesner's advice, I am proceeding to carefully make it right. Adding ballast to the nose will likely yield a 120 Kts airplane instead of the desired 150 Kts airplane. In the process I just may live to tell about it and be a better person to build another KR.
Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA ---------------------------------------------------------------------------------------------------- >The only thing I would think you would even consider changing is to make >the c.g. range in percentage of MAC only and not referenced to the leading >edge, +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ It's been some time since I looked at the plans but I seem to recall it being stated in percent of MAC and that translated to inches from the lead edge. If anything is changed like wing shape, length, winglets, the percent of MAC could/ will/ probably change also based on the new design and anything stated in the plans, like percent of MAC, also "goes out the window". As with building to plans, any changes made are still the responsibility of the builder, not the designer, to test and verify safety of the design. The designer is not seeking certification for your airplane, THE BUILDER IS. If the inspector notes something he / she is not comfortable with, they may not pass the inspection. If they sign it off it's all on you to test for safety. We are given a considerable latitude in the EXPERIMENTAL category. PROCEED RESPONSIBLY AND WITH CAUTION.......... Larry Flesner
