Critical Mach number and slow down as it travels around the aircraft's structure. When the aircraft's airspeed reaches the critical Mach number, the speed of the airflow in some areas near the airframe reaches the speed of sound, even though the aircraft itself has an airspeed lower than Mach 1.0. This creates a weak shock wave. As the aircraft exceeds the critical Mach number, its drag coefficient increases suddenly, causing dramatically increased drag, and, in an aircraft not designed for transonic or supersonic speeds, changes to the airflow over the flight control surfaces lead to deterioration in control of the aircraft. In aircraft
Mach Five protagonists build the Mach 6. The Mach 6's engine is not designed to run on gas, which is a crucial story point, even though gas is still used for it through most of the series. It has all the features of the Mach Five, but redesigned or changed in some form or another. For example, the rotary saws are kept, but they're turned into laser saws, and the blades can pivot so things that are over head can be cut. The new car features a transparent, holographic screen over the dashboard that the driver can use to interact live with