Don´t use pan/tilt/roll, try it with c_rotate.
This should work:

Code:

---

action plane_control
{
	my.polygon = on;
	while(1)
	{
		temp.x = 0;
		temp.y = mouse_force.y * time * 3;
		temp.z = mouse_force.x * time * 3;
		c_rotate (my, temp, IGNORE_YOU);
		my.tilt = clamp(my.tilt, -15, 15);
		my.roll = clamp(my.roll, -15, 15);
		wait(1);		
	}
}

---

Do you use a model or a mapentity as platform? Models are working better.