Flight Movement with Banking

I am attempting to make an airplane automatically fly around a series of points in space. Right now the movement is locked to a plane along the X/Z axis (Y never changes) but ideally I would like to keep the option for full 3D flight open. The airplane constantly moves forward, while rotating around the Y axis to face its target, causing a little bit of an arc as it moves towards its target.

So far it is working well, but I am not sure how to add banking to the rotation calculations. As the plane makes sharp turns I want the plane to rotate around its forward axis.

I am just using the built in Quaternion.LookRotation function. I’ve tried setting the Z-rotation directly after the rotation towards the target is complete, but it seems to cause problems with the movement towards the target, and sends the plan off in undesired directions.

    // Update is called once per frame
    void Update () 
    {
        // Get the current target.
        Transform currentTarget = targets[currentTargetIndex];
        
        // Get a vector from the current position to the target.
        // This is the vector we want to move our forward vector towards.
        Vector3 lookDirection = currentTarget.position - transform.position;

        // Calculate the rotation needed for this target look vector.
        Quaternion rot = Quaternion.LookRotation(lookDirection.normalized);

        // Rotate towards that target rotation based on the turn speed.
        transform.rotation = Quaternion.Slerp(transform.rotation, rot, Time.deltaTime * turnSpeed);

        // With the rotation complete, just move forward.
        transform.Translate(new Vector3(0,0,moveSpeed) * Time.deltaTime);
    }

Let me know if there is anymore information I can add.

Try:

float bank = 30f;
Quaternion rot = Quaternion.LookRotation(lookDirection.normalized) * Quaternion.AngleAxis(bank, Vector3.forward);

hey its really great bro.i too have the same issue i.e., me flight is turning in a curved way bt its not banking during turnings.actually i achieved banking and curved turning of the flight separately but i dont know how to integrate it together,below code makes the flight to bank:
float fullbank = 40;
float h = input.getaxis('horzontal")
plane1.transform.rotation = Quaternion.Slerp(plane1.transform.rotation,Quaternion.AngleAxis(fullBank,Vector3.forward * -h),Time.deltaTime * 1.5f);
but i want to bank my flight during turnings.plz help me .