Controlling flight direction from OVR head rotation

I am trying to make a flight controller with the OVRCameraRig prefab, where the plane forward direction will be equal to the OVR eye forward direction.

I have a "Plane" gameObject with the OVRCameraRig as it's child.

The Plane object has the following script attached to it:

 Quaternion rotation = OVRRig.rightEyeAnchor.transform.localRotation;
 Quaternion combinedRotation = transform.rotation * rotation;
 Quaternion relative =  Quaternion.Inverse(transform.rotation) * combinedRotation;
 transform.rotation = relative;

With this approach the plane does turn but only a fraction of the actual head rotation. For instance if looking on the right at 90degrees, the plan with steer right by lets say 40degrees.

I've also tried simpler approaches like:

 Quaternion rotation = OVRRig.rightEyeAnchor.transform.localRotation;
 transform.rotation *= relative;

This results with the plane incrementing its rotation by the amount or head rotation on every frame. Let's say i look 20degrees on the right the plane will keep turning around until I look straight. A little like having a joystick.

No matter what combination I try I always seems to end up with either of the above results, any help would be greatly appreciated.

Thanks