The Problem Boeing Ran Into After Designing Engine Chevrons

Boeing faced challenges with implementing engine chevrons, which reduce noise but also impact aerodynamic efficiency. Despite initial issues, chevrons are now a feature on the Boeing 737 MAX, 747-8, and 787 Dreamliner. However, Boeing opted for alternative noise-reduction methods for the 777X, such as advanced nozzle designs and acoustic linings, to avoid thrust penalties.