The other night I was in the AHIII MA testing my settings. My normal flight input is mode 1 for my joystick, but I accidentally hit my mode 3 button causing the mouse to take over. I have mode 3 set for GVing and to operate gun turrets. Some features remained effective on the joystick including the hat switch, fire buttons and rudder - but I had no aeliron or elevator input. The pov became stable so that I was always upright with respect to the ground even though the plane was doing barrel rolls.
In short, simply changing back to mode 1 did not fix the problem. It was like the game only acknowledged mode 3 at that point. I would have to tower out to get back to my normal mode 1 flight controls.