Actually I misremembered. It was not the plug style that causes issues but the size of the exit. The change from the throw out door to the hinge version in the

Actually I misremembered. It was not the plug style that causes issues but the size of the exit. The change from the throw out door to the hinge version in the NG is apparently a change they made to satisfy JAA: https://www.flightglobal.com/news/articles/boeing-details-emergency-exit-on-new-737-21088/ https://www.flightglobal.com/news/articles/boeing-details-em... Oddly enough that news bulletin says it's still a plug door which it clearly is not in the final design. Overall the root cause I believe is generally weight of doors and evacuation time. I had a few conversations about this around the time the second accident happened and grandfather rights were brought up by people from the industry I talked to as an expensive problem for a new type rating.