Not sure, but that seems to be a thing: https://www.popularmechanics.com/military/aviation/a26627917/air-force-kc-461-deliveries-trash-boeing/ https://www.popul

Not sure, but that seems to be a thing: https://www.popularmechanics.com/military/aviation/a26627917/air-force-kc-461-deliveries-trash-boeing/ https://www.popularmechanics.com/military/aviation/a26627917... > New KC-46A tankers fresh off the assembly line were found with “loose tools” and “bits of debris” in them left behind from the manufacturing process.