When Dave Calhoun, chief executive of Boeing, addressed its employees this week about a brush with disaster on a 737 Max aircraft carrying 171 passengers, he choked up. “I got kids, I got grandkids and so do you. This stuff matters. Everything matters, every detail matters,” he told them.I don’t doubt Calhoun’s sincerity but Boeing has made emotional pledges to improve its safety record before and those did not prevent this accident. No matter how hard it pulls at its internal controls to reform how it designs and builds aircraft, it has not fully changed course. The most famous aerospace company in the US has a big credibility problem.

The latest blow to its authority came last Friday when part of the fuselage of an Alaska Airlines 737 Max 9 jet blew out at 16,000 feet, inducing a sudden decompression. No one on board was injured or died, but it could well have proved as fatal as the twin crashes of 737 Max 8 aircraft in 2018 and 2019 in which 346 people perished.

This accident was different in nature: it appears to have been caused by the failure to install properly (or perhaps at all) bolts that were designed to keep a door-shaped panel in place. The likely cause was an oversight in manufacturing or assembly, rather than the earlier, catastrophic design flaw in the 737 Max’s flight control software.