While already at high speed, what happens if Mach is allowed to increase?

As speed increases and approaches Mach 1, several aerodynamic changes occur that can significantly affect aircraft handling and performance.

When the Mach number increases, airflow over various parts of the airplane can indeed exceed the speed of sound, which leads to the formation of shock waves. These shock waves generate pressure gradients and changes in airflow characteristics, impacting the lift and control of the aircraft.

Additionally, when shock waves form, they can disrupt the smooth flow of air around the wings and fuselage, resulting in airflow separation, which can compromise aerodynamic efficiency and control forces. This separation can lead to unexpected pitch responses, including pitch-up or pitch-down tendencies, and can also produce buffeting, a condition characterized by turbulence experienced by the aircraft.

Therefore, as the Mach number increases, all of these effects—airflow exceeding the speed of sound, shock waves causing separation, and changes in pitch and buffeting—can occur simultaneously. This comprehensive understanding of aerodynamic behavior at high speeds is crucial for pilots to maintain control and ensure safe flight.