Rotation problem - Change Roll of the mesh while yaw

Hello,
I am making a simple plane game. When you press up and down you change the pitch; right and left the yaw.
When the yaw change i would like the plane to slighty change is roll (visualy). So i made a parent with the script and a child with the model of the plane.

This is how i yaw:

Code (CSharp):

1.  if (Input.GetAxis("horizontal") < -0.5)
2.         {
3.  
4.             transform.Rotate(0, -15f * Time.deltaTime, 0);
5.          
6.             var target = Quaternion.Euler(0, 0, 45);
7.          
8.             PlaneMesh.transform.localRotation  = Quaternion.Lerp(PlaneMesh.transform.rotation, target, 0.5f);
9.        
10.         }
11.         else
12.         {
13.             var target2 = Quaternion.Euler(0, 0, 0);
14.             PlaneMesh.transform.localRotation = Quaternion.Lerp(PlaneMesh.transform.rotation, target2, 1f);
15.         }

But my quaternion.lerp don't work, the mesh yaw more than the parent and keep turning. If there is no lerp (1f) it behaves like i want but it's not smooth. Any idea ?

 

found the solution; forgot the localrotation on Quaternion

Code (CSharp):

1.  if (Input.GetAxis("horizontal") < -0.5)
2.         {
3.  
4.             transform.Rotate(0, -15f * Time.deltaTime, 0);
5.  
6.             //Faire Fn rotation pendant le Yaw
7.          
8.             var target = Quaternion.Euler(0, 0, 45);
9.          
10.             PlaneMesh.transform.localRotation  = Quaternion.Lerp(PlaneMesh.transform.localRotation, target, Time.deltaTime*1);
11.          
12.            // PlaneMesh.transform.localRotation = Quaternion.Euler(0, 0, 45);
13.             //PlaneMesh.transform.Rotate(0, -1/2, 0);
14.         }
15.         else
16.         {
17.             var target2 = Quaternion.Euler(0, 0, 0);
18.             PlaneMesh.transform.localRotation = Quaternion.Lerp(PlaneMesh.transform.localRotation, target2, Time.deltaTime * 1);
19.         }