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
Ford Mustang Mach 1 horsepower calculations. The following year also produced the fewest Mach 1 sales of the 1971-73 generation. There are no major differences in the '71 and '72 Mustangs externally, other than the addition of a "Mustang" script on the right side of the trunk panel (excluding Mach 1). The '72 Mach 1 also saw deletion of the pop-open gas cap, which was replaced with the standard twist-on cap found on the other Mustang models that year. The 302 Windsor remained as the base Mach 1 engine, with the 2 or 4 barrel 351 Clevelands as the only options. In 1973, the