I am surprised that the speculation says just over the summer season. I have heard reasonable and sober sources stretch the dates out to the year's end. I do not have purview to venture an estimation but running it out twelve months would not surprise me.
Maybe reduced rates on 777s might fill the breach until the behind the wire reserve battalions can move forward. At least in the U.S. there are an innumerable number or 50 seat regional jets that can step up to do yeomen's duty. They nailed their flag on to the little frames that the passengers
Love...
I do think it will be fall before we see real possibilities for a flying test plan. Could be wrong. Lots of work to be done and the other countries will be watching closely.