NASA spent years developing chevron technology for airliner engines in an effort to make aircraft quieter, which became one of the more iconic external features of the Boeing 787 Dreamliner. But Boeing has already moved beyond those quieting chevrons with its incoming Boeing 777X family powered by the huge GE9X turbofan engines. The massive size of the GE9X engines provides them with an inherent advantage that makes it easier to dispense with the chevrons and the small but measurable penalty they entail.