Mach cutoff flight can result in secondary sonic booms

Supersonic aircraft require specific atmospheric conditions to achieve Mach cutoff flight. Previous studies have demonstrated it is possible to fly under Mach cutoff conditions, enabling overland supersonic flight without generating loud sonic booms below the flight path. However, while atmospheric conditions closer to the ground may enable Mach cutoff flight, certain upper atmospheric conditions can still lead to secondary sonic booms. This study investigates the atmospheric conditions that enable Mach cutoff flight while simultaneously generating secondary sonic booms due to upper atmospheric winds. We examine seasonal timing, geographic location, and altitude as key parameters to determine their resulting impact on ground-level noise due to secondary sonic booms created by Mach cutoff operations. [Work supported by the FAA through ASCENT Project 57 under the supervision of Sandy Liu. Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the FAA.]