I'm testing the waters of twin-fuselage aircraft engineering and I'm having a bit of a problem with my lite practice craft if you will. It'll pitch fine and good if spawned in the air but after a bit of flight time or after a nudge into rolling it begins to spin about like a dodgy compass, doing what it likes yaw-wise. The problem might even be blatant to my more seasoned peers here but nonetheless here is a peek:

Typically the issue lies with faulty verticle stabilisers or a lack thereof but I've tweaked them every which way to no avail, making sure to re-mirror each time as well.

(also thanks to MemeKingIndustriesAndMegaCorporation for showing me how to do image tags!)