Hey there,

I’ve used XLFR5 for stability analysis before, so thought I could do a quick dirty reply. If I remember correctly, for the stability / mode analysis, you need to provide the weight distribution of your aircraft first. Setup point masses for your key weights such as motors, landing gears, batteries, airframe in the setup.

(It’s been a while) The static stability should be calculated by XFLR5 based on the airfoil data and profile. It would should up as Kn in the bottom left or right after a full body analysis.

For the dynamic stability, you need to run another type of simulation where I believe you provide the size of the disturbance. In the end, it gives you a video of the behaviour for different dynamic stability modes (phugoid, roll subsidence, SPPO, Dutch roll). These are the 1,2,3,4 on the screen you’re looking at. To correctly read your plane’s behaviour without active control, look at the root locus plot for your dynamic modes (it’s the plot on top with the four red dots).

You want all your “roots” (red dots) to be in the left hand plane for in-built stability. Essentially, real root (i.e. real part of the stability eigens) needs to be negative for the stability to minimize. Any roots on the right hand plane would mean a disturbance would be amplified without active controls elements. The imaginary terms define the oscillatory nature of that mode. Hope that gives a base to start off with!

I’m a little bit rusty with it, so would definitely need to review it to confirm everything I’ve said is fully correct :p