section_path: Development/Quality-control issues (2019–2025)/2020
section_name: 2020
paragraph_text: 2020
  
  Early in 2020, Boeing engineers complained about depressions in the 787's vertical tail fin, affecting hundreds of planes or the vast majority of the fleet. Workers in Charleston and Everett had improperly discarded shims before the final installation of fasteners, which could lead to structural failure under limited loads. In late August 2020, Boeing grounded eight 787s due to such improper fuselage shimming and inner skin surfacing issues—issues which proved to have been discovered in August 2019 at Boeing South Carolina.
  
  The following month, Boeing admitted that "nonconforming" sections of the rear fuselage did not meet engineering standards, and the FAA was investigating quality-control lapses dating back to the introduction of the 787 in 2011 and considering requiring additional inspections for up to 900 of the roughly 1,000 Dreamliners in service. The FAA then began to inquire into the company's Quality Management System (QMS), which Boeing had previously argued justified a reduction of 900 quality inspectors, but which had failed to detect either the shim or skin surface issues. A third quality-control issue then emerged, this time with the 787's horizontal stabilizers, and affecting as many as 893 Dreamliners: workers in Salt Lake City had clamped portions of the tail section too tightly, which could lead to premature material fatigue. At this point Boeing expected a one-time inspection during regularly scheduled maintenance to address the issues and expected merely to slow 787 deliveries "in the near term".