Rigid body rotation question

Hi, iam working on this game where you sort of fly a rc plane and i have this problem with rotation… When i try to turn the plane around, it continues flying in the direction it was flying before instead of a new direction achieved through rotating.
Iam moving the plane using

var plane : rigidbody;

var planetran : Transform;

plane.AddRelativeForce(planetran.forward* (speed - plane.velocity.magnitude));

and Iam rotating the plane with

transform.eulerAngles.y += rotat;
//where "rotat" is incriesed or decreased based on which direction i want to turn

Ive tried both addforce and add relative force but it seems to have the same effect.
The plane does turn a little bit but the moment I turn a little bit more than just about 5% it ends up flying sideways and also accelerating to enormous speeds…

If you want the force to be along the object’s forward, you must use AddRelativeForce as you are. Relative force is applied to the Local transform. I also suggest using transform.Rotate instead of eulerAngles. As the page here: Unity - Scripting API: Transform.eulerAngles suggests that it will fail after 360 degrees, not something I would think you want.

On this page: Unity - Scripting API: Transform.Rotate
The last script example shows Rotation around the x-axis at 1 degree per second. Change that to the y-axis and change the degrees per second.