Thanks again Larry for your excellent elaboration on the CG sensitivity issues, especially for small aircraft. So, adding airspeed could effectively changing the CG position at least momentarily, or it allows the pilot more control authority over control surfaces....
Another way I could think of, on mitigating such CG violation risks, is to prepare a two or three ponder weights (such as a small backpack or suitcase etc) inside the cockpit where you can easily grab on and quickly place it in the head or aft position in case needed, perhaps... Another way (just my thoughts for CG sensitive small aircraft) which may be worth trying is to design some simple mechanism on the luggage loading space, where the base could be made moveable at few inches back/forth flexibility. Such moving of luggage weight position doesn't need to be complex or motor driving, of course! This could be a life-saving design upgrade considering CG issue is such an imperative safety risk on GA aircraft, especially for the EAA community... Stay safe & fly high! Dr. Hsu On Mon, Aug 10, 2020, 10:11 AM Flesner via KRnet <krnet@list.krnet.org> wrote: > On 8/9/2020 11:30 AM, Dr. Feng Hsu via KRnet wrote: > > If there is any uncertainty about the CG > > spot, or to put the last two ponds of extra luggage during loading, > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > In spite of our many posts I keep thinking that flight characteristics > have not been expressed in a more meaningful way with regard to CG. > > Flight characteristics do not remain in perfect harmony throughout the > CG range and then, at some point they reach a limit and a one or two > pound difference makes the aircraft uncontrollable. This does no happen > , for example, like a stall break. Handling characteristics deteriorate > gradually as the CG / CL change during flight from ideal to a point > where they approach the forward or aft limit. The pilot should be > noticing this change with necessary changes in stick forces and aircraft > response to control inputs. Increased airspeed or load shift are about > the only two immediate options available to the pilot when the limit is > reached as Mark did on his flight. Load shift is obvious. Increased > speed gives more control surface authority. Just remember, the higher > the speed you use to overcome a bad CG, the more energy you need to > dissipate when the flight comes to an end. If the outcome is not > controllable the more disastrous the end result. > > Adding an extra pound or two here or there during build does not > necessarily make for an uncontrollable airplane. It merely limits your > loading options for safe flight. > > Larry Flesner > > > > _______________________________________________ > 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
