Hi John, Hi Tinstaafl
I suppose it depends on whether you are in the northern or southern hemisphere!
I'd better come clean on this. Alex and I have been arguing about stability. He holds that most transport aircraft have the CP at or just aft of the basic CG, giving a wing couple that is stable and just needing the tail to add more stability. I hold that the CP will be forward of the CG, giving an unstable wing couple that is then adjusted by the tail design to give the stability required. This may sound like "how many angels can dance on the head of a pin?" but we need to keep all our P of F sections, Performance, M & B, etc. in line and would like to have a real, definitive, answer. Trim, trim forces and the up and down load on the tail are secondary problems, and not in dispute.
There are lots of experts here on Prune, so I tried to get an answer without starting a wide-ranging discussion about stabilty. I guess we will have to ask the design authority.
regards to all, Dick W
Last edited by Dick Whittingham; 15th Apr 2002 at 08:37.