Having seen the fatigue test 777X emerged from the production hangars (as I covered in this post), I assumed it had moved to the test area. I once made a drive around the back of the factory at Everett to see some of the discarded airframe structures that they have stored once they are finished with.  I wrote about that in this post.  The fatigue test area is in the same place so I thought a drive around was a good idea.  Sure enough, the 777X was in the fatigue test rig.  I guess it will be there for quite a while as they push and pull it to simulate many cycles of loading and see whether the structure has any long term issues to be addressed.