No One Knows How Dangerous Boeing’s 737 Max Actually Is

A faulty automated system leaves lingering questions

After a Lion Air 737 Max crashed in Indonesia last October, killing all 189 people aboard, Boeing anticipated that the plane’s flaw would be relatively straightforward to fix. A faulty sensor had caused an automated system to kick in and push the plane’s nose down; the startled flight crew struggled against the system and eventually lost control. Boeing set about rewriting the control-system software, so it wouldn’t misbehave in the same way again, and issued a directive telling pilots how to deal with such situations in the meantime.

When an Ethiopian Airlines 737 Max went down less than five months later under similar circumstances, killing all 137 people onboard, it caused a worldwide furor—and ultimately the grounding of the entire 737 Max fleet. But Boeing still stood behind its plane. The assumption was that the Ethiopian Airlines pilots had lacked the skills and training to follow Boeing’s advice. (Much was made of the pilot’s “panicky” voice during the incident.) “The 737 Max is a safe airplane that was designed, built, and supported by our skilled employees who approach their work with the utmost integrity,” the company said in a prepared statement the day after the crash.

While the twin catastrophes were embarrassing in the short term, Boeing hoped that a few quick tweaks to the faulty automated system would suffice to win back public trust in the plane. These tweaks, however, may not account for the sheer complexity inherent to the software underlying the 737 Max. Lingering problems could slip by regulators and put passengers at risk.

Developments over the last few days have already undermined the notion that Boeing has the problem under control. Ethiopia’s Ministry of Transport released its preliminary accident report yesterday showing that, based on analysis of black box data, the pilots in fact had done just as Boeing’s directive had suggested, but to no avail. Ethiopian Airlines issued a statement declaring that its pilots “followed the Boeing-recommended and FAA-approved emergency procedures to handle the most difficult emergency situation created on the airplane. Despite their hard work and full compliance with the emergency procedures, it was very…