Fan blade failure/engine certification

[tdracer]

Originally Posted by Jwscud

I was thinking more of large departing chunks of the cowling heading towards the empennage.

That's why this event (and the previous 2016 Southwest event) will probably end up with a two major corrective actions. First of course is to prevent the fan blades from failing - first step in that process is the inspection AD that is already out. I'd expect eventually there will be a design change to the blade to alleviate the fatigue cracking.
The design intent is that the inlet (and the rest of the cowling) remain intact during a fan blade out event. These events demonstrate that there is some shortcoming in the CFM56-7 inlet design since it's failed - twice. So I have to assume that some of my buddies in Renton are busy figuring out why it failed and how to fix it. I have little doubt that there will be a Boeing Alert Service Bulletin in the future to strengthen the inlet so it doesn't come apart if/when there is a future CFM56-7 fan blade out event.