LesterBoffo wrote:I agree that the default AP has too quick a reaction time, but.. The forces on the aircraft's fuselage should be more than adequate to damp out a few phugoid cycles despite the trim over run. When at 33.000 feet and at level flight with the default AP off, see how many aircraft will damp their phugoid within a couple cycles when your joy stick is neutralized. The fuselage is a huge stability factor at 300+ knots. Both FG fdm's, if made at their very basest of coding do not have much if any fuselage damping.
The fuselage dampens ? I'm not sure it does.
Longitudinal damping is very much a product of the h-stab's decalage to the main wing, along with the increase/reduction in AoA on the h-stab caused by the rate of its rotation.
A problem I also see is that the trim fcs code in for example jsbsim doesn't really reflect what's happening in real life... I'm not saying it's wrong for every plane but that the mechanics of trim are different for a WWII plane to a fast fly by wire jet.... so which trim is being used ?
Simon