So no one knows, yet, what happened in the Ethiopian Airlines disaster, and anyone who feigns certainty now should be viewed with wariness.
But here is an initial guide to the kinds of questions air investigators will be asking.
What’s the (possible) similarity between this crash and the Lion Air disaster in October 2018, in Indonesia, in which 189 people were killed?
The main known similarity at this point is that they both involved the same, relatively new model of airplane. This is a new version of the workhorse Boeing 737, known as the 737 Max 8. Both of the planes crashed shortly after takeoff—not mid-flight, like the Air France disaster over the Atlantic 10 years ago, and not on approach for landing, as with the Colgan commuter-airline crash en route to Buffalo in 2009.
What’s significant or different about this new plane?
The 737 is the most familiar and popular commercial airliner in the world. It’s been in production since the 1960s, and more than 10,000 of them have been in service. If you’ve ever taken a ride on Southwest Airlines, you’ve been on a 737, because it is all that Southwest flies. Complete standardization of the fleet has been an important part of Southwest’s business model since the start. (When I was working for Texas Monthly, back in the 1970s, I interviewed the late Herb Kelleher, a founder of the then-nascent Southwest, who stressed that with a single model of aircraft, everything about running an airline became simpler. Any pilot who worked for the airline could fly any plane the airline owned. Any mechanic at any Southwest repair facility would have the right parts for any plane that arrived, because all the planes were the same. I wrote about this part of Southwest’s vision in 1975, during the era of airline regulation, in Texas Monthly.)
Aircraft makers themselves have obviously invested in an evolutionary series of airplanes for different markets and circumstances. Thus we have, from Boeing, the long sequence from the now-obsolete 707, to the iconic and mainly decommissioned 747, to the 777 and 757 and 787 “Dreamliner,” and version after version of the 737.
Okay, but what’s “new” about this plane?
The “version after version” part is what’s significant about the 737. Airlines like it because it is standardized. Training, crew certification, parts, maintenance, are all much more similar than if you’re switching to a different model—such as a 787—or making the more dramatic shift to Airbus.
But airlines also want constant improvements: better and more efficient engines, improved avionics and other systems, and of course, more (and more crammed-in) seats. Thus the 737 range goes from the early 737-100 models, meant to hold about 100 passengers, to the latest models, which (depending on layouts) can hold 200 or more.
The 737s have gotten physically longer over the years, to hold more passengers, and that is part of the drama involving the latest model, which went down in both the Indonesian and Ethiopian crashes.