https://tech.slashdot.org/story/20/02/22/0812248/after-inspecting-50-airplanes-boeing-found-foreign-object-debris-in-35-fuel-tanks
"Materials left behind include tools, rags and boot coverings, according to industry officials familiar with the details... [T]he new problem raises fresh questions about Boeing's ability to resolve lingering lapses in quality-control practices and presents another challenge to Chief Executive David Calhoun, who took charge in January... Last year, debris was found on some 787 Dreamliners, which Boeing produces in Everett, Washington... Boeing also twice had to halt deliveries of the KC-46A military refueling tanker to the U.S. Air Force after tools and rags were found in planes after they had been delivered from its Everett factory north of Seattle. "
How does something like that get by? I mean, I guess I could understand one or two things once in a while - stuff does happen, edge cases, etc. But 35 of 50 inspected? Even if they don't find another, 35 out of 400?