How would I make the Y axis of obj1 the same as obj2


I’m creating a UFO vs helicopter game (3d shooter). My AI script works but my Choppers always seem to be at the same height. Is there a way to make the Y position of my choppers the same as my UFO (with Damping);

var newChopperPos = new Vector3(chopper.position.x, UFO.position.y, chopper.position.z);

chopper.position = Vector3.SmoothDamp(chopper.position, newChopperPos, velocity, Time.deltaTime * damp);