The comments Monday from the National Transportation Safety Board came shortly after Alaska and United Airlines reported separately that they found loose parts ... other Boeing 737 Max 9 jets.

More than 40 foreign operators of Boeing 737 airplanes ... of these actuators on their 737 airplanes," NTSB Chair Jennifer Homendy said. The issue adds to the long list of setbacks for Boeing.

Here's a short list of some of the quality-control headaches and public-relations crises Boeing has endured: 737 Max 9 blowout In January, a Max 9 door plug blew out on an Alaska Airlines flight ...