Boeing Keeps Stretching the 737. Here’s Why That’s a Big Problem.

Why was the emergency door that blew out of the Alaska Airlines Boeing 737 MAX-9 there if not needed? The answer to that question reveals how far some airlines will go to pack a cabin to its limits—and how far Boeing is willing to go to accommodate them.

The MAX-9 is the largest (so far) of the 737 MAX series. At maximum permissible coach density it can have 220 seats. The Alaskan version has 188 seats: 16 in First, 24 in premium and 138 in coach. That difference meant that the emergency exit at row 26 was not required to provide additional emergency evacuation of the cabin in the case of a crash. Hence it was “plugged”—supposedly locked securely in place. Except that it wasn’t, as investigators have already discovered, along with numerous other manufacturing defects on other MAX-9 jets.

Behind this event is the amazing story of the little airplane that suddenly began to get a lot larger. As each model of the 737 has appeared the cabins have become longer and longer… and longer.

Read more at The Daily Beast.