The 'RW Designs' Otter I have has a really bad pitch oscillation (not pilot induced).  None of my other planes do this which rules out the stick, I think.  Is there an adjustment area in 'Planemaker' where dampening pitch sensitivity would be possible? 

What phase of flight? Takeoff, climb, cruise, descent? Does it enter and exit autopilot control smoothly?

I haven't noticed this with my RWD Twotter, but it's been a while since I've flown it. It always seemed a well-tamed (if not actually boring) plane to handle.

Check the following ( don't recall exactly where in the interface … ) 

.) Pitch Radii of Gyration - is it using the default ( not showing ) or manually edited ?  If it is edited, it's tricky to play with it, but you could try to lower it, say, 10% …

.) Control Phase-Out: Under the controls section of wings ( if I'm not wrong ) there's a tab where you can define the fade-out of control authority with IAS. This is used by many authors to replicate ( in a wrong way but not Austin's fault... ) the stiffening of controls with dynamic pressure. Some authors make it reduce considerably bellow a given IAS.

.) Artificial Stability, which kicks in even if you have your artificial stability sliders full left in X-Plane 11. Check the pitch channel in Art Stab in Plane Maker and see if something I programmed there to "tame" pitch bellow / up a given reference IAS.

 

 

Edited December 9, 20187 yr by jcomm

Yes it 'bobs' in all phases/power settings.  I try to avoid the 'stability settings' at all costs and will try Jcomm's suggestions.  I too have the RW DHC6 - no problems.

Just joined AVSIM and am investigating XP for use in home project.  From review of manuals (XP and PM) cannot find any info on getting AC pitch, roll and yaw inertias defined in input.  Any guidance and some clarity that they are covered and how would be greatly appreciated.  Can't go forward without this basic info.

The inertia entries in plane maker (in the weight and balance tab, IIRC) represent the radii of gyration for the 3 aircraft axes, in feet. XP takes those values (Rx, Ry, Rz) and the actual aircraft mass (m) to calculate moments of inertia (Ix, Iy, Iz) along the 3 axes:

Ix = m * Rx^2

Iy = m * Ry^2

Iz = m * Rz^2

To estimate realistic values, you need some technical knowledge. In "Airplane Design" by J. Roskam, there are tables and formulas that allow you to estimate those values according to type of aircraft, wingspan, length, etc. I think Roskam book can be found online... (It's 6 or 8 volumes total).